EEVblog® Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: VEGETA on April 06, 2024, 12:09:32 am
-
Hello,
I have designed and sold this product: https://thundertronics.net/product/dreamcast-universal-power-supply/ (https://thundertronics.net/product/dreamcast-universal-power-supply/)
I am currently making a batch of 40 which are expected to be sold fast too... However, I am using a very good and expensive power module from Recom (https://www.digikey.com/en/products/detail/recom-power/RACM30-12SK-277/17801494).
PCB manufacturer gets it for me for about 23-24$ in quantities from suppliers like Digikey and Element14-CN. I got quotes from manufacturer themselves for 12.1$ per unit in quantities but I have to set shipping carrier account...etc. Overall still very expensive component.
I wanted to go to next level and design my own flyback regulator... it outputs 12v or 15v then I hook whatever buck regulators after it as I need.
I contacted Power Integration and they suggested Innoswitch3 IC and gave me example design with everything detailed. they said the transformer can be made from magnetics makers for 7$.
I contacted Prem magnetics and they are looking into this suggested transformer design... if price is ok i will modify the design to my liking which won't be much different.
I cannot wind my transformer myself for many reasons, I have to get it ready and delivered to pcb manufacturer.
Kindly inform me about your experience doing this + the cost of this circuit especially the custom transformer. Is it realistic that I hope the transformer be in 2-5$ range? what other good manufacturers (in China for example, but still good) that can make it cheaper?
please give me full recommendation and your experience doing this.
P.S: this product is for Dreamcast and it is 30W (DC is just 22W), I am doing a Saturn version which is <15W and could do more versions for other devices and stuff. Current design has noise and ripple value of <25mv p-p (a third party friend confirmed 15mv) and it is ice-cold. Only downside is BOM cost and availability.
I attached the Innoswitch3-CE suggested design for 15v 2A max output + all transformer details.
-
The transformer size will be dependent on switching frequency, primary inductance and power rating. The circuit from Innoswitch3 looks good and quite efficient with a synchronous rectifier on the secondary side, handling the regulation and isolation in one chip is an added bonus. Custom transformers can be quite cost effective when ordering in bulk, just be sure to choose a magnetic core that has good availability, like ICs not all cores are equally available and you would like your transformer design/pcb layout to last the test of time.
Just one problem, certification, devices connected to the mains need to be certified and pass qualification testing. This is probably one extra thing your purchased PSU did for you.
-
The transformer size will be dependent on switching frequency, primary inductance and power rating. The circuit from Innoswitch3 looks good and quite efficient with a synchronous rectifier on the secondary side, handling the regulation and isolation in one chip is an added bonus. Custom transformers can be quite cost effective when ordering in bulk, just be sure to choose a magnetic core that has good availability, like ICs not all cores are equally available and you would like your transformer design/pcb layout to last the test of time.
Just one problem, certification, devices connected to the mains need to be certified and pass qualification testing. This is probably one extra thing your purchased PSU did for you.
what cores do you suggest I use?
as for certifications, i won't need them since i sell direct or via some niche suppliers in retro gaming industry. won't need any certifications as also i never needed them when i sold my current design itself.
how much does the transformer cost in your opinion? approx.?
-
> PCB manufacturer gets it for me for about 23-24$ in quantities from suppliers like Digikey and Element14-CN. I got quotes from manufacturer themselves for 12.1$ per unit
https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12C_C18203068.html (https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12C_C18203068.html) - $5.45
https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12_C2761166.html (https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12_C2761166.html) - $10.49
https://www.lcsc.com/product-detail/Power-Modules_TDPOWER-TAS30-12-W_C570985.html (https://www.lcsc.com/product-detail/Power-Modules_TDPOWER-TAS30-12-W_C570985.html) - $8.1
Take a look also at Meanwell and Chinfa models.
Recom is a quite expensive manufacture.
-
> PCB manufacturer gets it for me for about 23-24$ in quantities from suppliers like Digikey and Element14-CN. I got quotes from manufacturer themselves for 12.1$ per unit
https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12C_C18203068.html (https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12C_C18203068.html) - $5.45
https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12_C2761166.html (https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-30M12_C2761166.html) - $10.49
https://www.lcsc.com/product-detail/Power-Modules_TDPOWER-TAS30-12-W_C570985.html (https://www.lcsc.com/product-detail/Power-Modules_TDPOWER-TAS30-12-W_C570985.html) - $8.1
Take a look also at Meanwell and Chinfa models.
Recom is a quite expensive manufacture.
yes i know recom is expensive but very high quality and safe (medical rated). chinese units are not guaranteed to be safe and reliable as you well know. i marketed the device as a safe PSU, since you can find other solutions for that market which are not safe enough. this one was labelled a premium product by customers which it is for sure.
I know recom is expensive but it fits my pcb tight space and so on... it also has all components inside like input protection unlike most others.
-
as for certifications, i won't need them since i sell direct or via some niche suppliers in retro gaming industry. won't need any certifications as also i never needed them when i sold my current design itself.
"yes i know recom is expensive but very high quality and safe (medical rated). chinese units are not guaranteed to be safe and reliable as you well know. i marketed the device as a safe PSU, since you can find other solutions for that market which are not safe enough. this one was labelled a premium product by customers which it is for sure.
I know recom is expensive but it fits my pcb tight space and so on... it also has all components inside like input protection unlike most others."
You realise that there is a contradiction in these two statements? You buy the Recom because it is medically rated and very safe, but you don't need to certify a supply you build yourself? Also Meanwell are very decent PSUs, it takes experience to make good PSUs.
-
as for certifications, i won't need them since i sell direct or via some niche suppliers in retro gaming industry. won't need any certifications as also i never needed them when i sold my current design itself.
"yes i know recom is expensive but very high quality and safe (medical rated). chinese units are not guaranteed to be safe and reliable as you well know. i marketed the device as a safe PSU, since you can find other solutions for that market which are not safe enough. this one was labelled a premium product by customers which it is for sure.
I know recom is expensive but it fits my pcb tight space and so on... it also has all components inside like input protection unlike most others."
You realise that there is a contradiction in these two statements? You buy the Recom because it is medically rated and very safe, but you don't need to certify a supply you build yourself? Also Meanwell are very decent PSUs, it takes experience to make good PSUs.
I mentioned the high ratings of recom in product description, and will be mentioned in product video when it is done. it is just that i don't want to do any official certification for my product.
yes meanwell are nice, it was my first choice but the space is so tight and it didn't fit. recom one is shorter... the 12v 30w ones anyway.
the topic of this discussion is about flyback converter and custom transformer design, not power modules. i did ask about power modules here before and got similar recommendations to use recom or meanwell.
overall, getting a custom transformer with innoswitch could be cheaper in the long run but i wanted to ask if someone went this route to help me by giving details about custom transformer price and reliability of this solution. since all these power modules are just that, a flyback converter with input + output filtering and protection.
-
Custom flyback is a not simple thing to develop. First of all there is not a transformer in flyback but a multiwind inductor. They have different construction and can't be interchangebly used. Flyback inductor has a air gup in core, and this gap is essential.
Next - China supplier will not produce custom goods, they specialise on mass product, and flyback inductor is not a 'mass product'
On the other hand, even custom China based inductor still be Chinese product, and reliability of whole power supply will be compromized by this inductor. So why you think that ready made Chinese module will be less reliable?
It you want to find something ready nade you should take a look at Coilcraft for example.
As for custom designed flyback - I'd made one mamy time ago . It was based on TOP2 family from PowerIntegration and custom transformer (made on EPCOS ferrite). It works fine 24/7, and finally blown up after 5-8 years of service.
-
40...few 100 pcs not worther the NRE, MPQ to DIY the SMPS.
Get a cheaper off the shelf module, from China if you like to.
suggest you learn a bit....find and Read a few SMPS texts on design and magnetics, safety and compliance.
j
-
How about just have a DC input and include a wall wart with the product?
-
Custom flyback is a not simple thing to develop.
everything is done by power.com tools. if i settle on a certain design then i will get a sample transformer from them since they have such a service. after that i can check to see who can make them for me. right now i am waiting prem magnetics to respond.
i want to use innoswitch3 ic
40...few 100 pcs not worther the NRE, MPQ to DIY the SMPS.
Get a cheaper off the shelf module, from China if you like to.
suggest you learn a bit....find and Read a few SMPS texts on design and magnetics, safety and compliance.
my product works fine as it is now, i am just looking for cheaper ways to make it.
Hi-Link modules are so nice in terms of price, no argument there. like 5$ for the 30w version! do you think such modules are good and safe to use? also do not produce much heat at max 22W?
current recom one is fantastic in all terms, heat, performance and so on.it has everything included in terms of input protection too.
right now i am doing a saturn power supply which i used Mornsun module (https://www.mornsun-power.com/html/pdf/LS15-23B12DR3.html). it is about 5-6$ vs the Hi-link module (https://www.lcsc.com/product-detail/Power-Modules_HI-LINK-HLK-15M12C_C18203065.html) which is <3.5$. both require external components.
the current market of retro psu replacements do not like chinese stuff, labelled as low quality. do you think hi-link ones are good quality?
How about just have a DC input and include a wall wart with the product?
tons of solutions in the market like this and people do not like them. the idea is plug-and-play high quality, safe, universal, power supply replacement
-
I guess just get some of the cheap ones and do some testing on it? The big ones I can think of are thermals under load and a hipot test from primary to secondary. Should be pretty straightforward to make test jigs for those and randomly test a few units from each batch received if you're concerned about them cheaping out the design in the future.
-
Mornsun is a quite respectable manufacture. All there modules certified and has very good documentation. But be aware that many Chinese manufacturers making clones of these modules (under its own names).
HT-Link also made certified modules, but it less known for public and its documents not so high quality (and mostly in Cheese). I think these modules can also be used, but they require some testing beforehand.
-
I designed another PSU for Sega Saturn using Mornsun module: https://www.mornsun-power.com/html/pdf/LS15-23B12DR3.html (https://www.mornsun-power.com/html/pdf/LS15-23B12DR3.html)
still not finished but I think of replacing it with Hi-Link one if it is high quality. I can do testing for prototype unit but cannot do that for each batch. all other batches will be produced and sold.
I have designed a good input protection circuit for the Mornsun one following datasheet maximum recommendation, please check it in attachment. I can use the exact same one for the Hi-Link. It also uses resettable fuse protection after the module (12v output) for extra layer of protection.
If I made a PSU like that, what would the tests be? I have an electronic load where I can use it to draw current at rated or above to see thermal behavior and then to see if short circuit protection works...etc those are the ones i can think of.
Hi-Link ones are of a price I cannot neglect anymore. Like for my Dreamcast power supply, instead of about 24$ for Recom one I can get Hi-Link one for <5-7$! if I put my own protection (like in attachments) then I guess it will give exact same protection and safety, just without the medical certifications.
is it a good move?
EDIT:
HLK-30M12C is about 4.12$ in 100 quantity, 86-88% efficiency which should be good enough not to generate heat. especially that i will run it at maximum 22w not 30w.
there is this HLK-40M12 GaN module claiming 91% efficiency but nearly double price, not worth it for me to get this at this price.
-
From a business POV - does it make sense to redo the design?
If you are doing a production run of 40pcs. - and maybe save 200$, while going from a "known good" design to "who knows how good this will be" - where is the savings? Assuming you could earn some money elsewhere, or use that time to design another project.
-
From a business POV - does it make sense to redo the design?
If you are doing a production run of 40pcs. - and maybe save 200$, while going from a "known good" design to "who knows how good this will be" - where is the savings? Assuming you could earn some money elsewhere, or use that time to design another project.
it costs me around 45-50$ to make, I sell it for 85$ and this is the first batch so I will see how it sells. it is expensive for sure, and selling to retailers will reduce profits.
Making it significantly cheaper means i can sell it for less and gain more profit.
I am already making another project which is a power supply for Sega Saturn, in this one I will try putting Hi-Link module since it is very very cheap tbh. saturn is rated at 10-12w and the power module is about 15w so much room available. with my protection circuit i think it will be fine. will do some tests for sure.
many solutions are there in this market but none provide a universal plug-and-play same formfactor like i do. plus low noise, very low heat, high quality...etc I want to keep doing this at same level.
If Dreamcast PSU is sold for 70$ instead of 85$ it will be huge as no one would get the other solutions since they will cost about the same. assume 70$ selling price and now about 30$ cost if using cheaper module... means 40$ profit. while now 85$ - 50$ = 35$ or so.
I think I will see what performance it will deliver in Saturn PSU when I do prototype, then will do a prototype for DC.
-
Rebonjour:
Exactly what is this product, market, sales area eg US, UK, EU, Worldwide?
What is the load?
Safety and EMI compliance needed or ignored?
I would estimate 3..6 months.. to design, protp, debug and get compliance and get delivery on any DIY offline SMPS.
For modules suggest the many USA old line firms eg Lambda.
Nowadays 99.9% of elctronics made in Commi china , USA major brands use better fab, parts and QC than any CCP junk.
We like and have bought many from Lambda/TDK USA
https://www.us.lambda.tdk.com/products/acdc-power-supplies/pcb-mount.html (https://www.us.lambda.tdk.com/products/acdc-power-supplies/pcb-mount.html)
Avail from DK
https://www.digikey.com/en/products/detail/tdk-lambda-americas-inc/PH50A280-12/4519350 (https://www.digikey.com/en/products/detail/tdk-lambda-americas-inc/PH50A280-12/4519350)
Bon chance,
Jon
-
Rebonjour:
Exactly what is this product, market, sales area eg US, UK, EU, Worldwide?
What is the load?
Safety and EMI compliance needed or ignored?
I would estimate 3..6 months.. to design, protp, debug and get compliance and get delivery on any DIY offline SMPS.
For modules suggest the many USA old line firms eg Lambda.
Nowadays 99.9% of elctronics made in Commi china , USA major brands use better fab, parts and QC than any CCP junk.
We like and have bought many from Lambda/TDK USA
https://www.us.lambda.tdk.com/products/acdc-power-supplies/pcb-mount.html (https://www.us.lambda.tdk.com/products/acdc-power-supplies/pcb-mount.html)
Avail from DK
https://www.digikey.com/en/products/detail/tdk-lambda-americas-inc/PH50A280-12/4519350 (https://www.digikey.com/en/products/detail/tdk-lambda-americas-inc/PH50A280-12/4519350)
Bon chance,
Jon
it is a power supply for retro gaming console, market is worldwide but mostly USA. No compliance or anything needed, just the confident that the product works fine without any safety problems.
those lambda modules are very expensive, no way i can use them in such a product.
-
see
https://webench.ti.com/power-designer/switching-regulator?powerSupply=1
for some ideas. It will give you the magnetics design too. You can farm out transformer winding to a third party.
I'm thinking that I'd farm out the whole project to a Shenzhen Prototyper to maximize my margin. Get a quote or thousand!
If you want to sell into international and domestic markets you need to show EMC and safety compliance for the device as a whole.
-
see
https://webench.ti.com/power-designer/switching-regulator?powerSupply=1
for some ideas. It will give you the magnetics design too. You can farm out transformer winding to a third party.
I'm thinking that I'd farm out the whole project to a Shenzhen Prototyper to maximize my margin. Get a quote or thousand!
If you want to sell into international and domestic markets you need to show EMC and safety compliance for the device as a whole.
Power.com already gives detailed transformer design, all it remains is to make it. this one i forwarded to prem magnetics but they still didn't respond.
I created everything else, since i can do it cheaply and in high quality. please check the product link above.
as for selling, i will be selling via my own website which delivers to people via mail shipping... and via some known distributors which never ask for any certifications. they sell other solutions which are less quality too,.
-
Within the EU it is mandatory that your product complies with one of the relevant safety standards. If you can not prove that your product meets these safety standards, then it is forbidden to sell these products within the EU. The construction of a flyback converter is critical for safety in particular when it is powered from the mains. If you have sold products where you did not perform a safety assessment, then it might have legal impact.
The same applies for EMI/EMC. You need to verify that your product meets EMC standards. You are not allowed to sell your product without testing. EMI certification by a lab can easily cost 10K. The safety assessment you can do your self, but you need to have experience with this
Another thing to take into account is that custom designed transformers usually require minimum order quantities (>1000?). So for this reason if your sales volumes are low it is probably better to keep using modules of Recom, Traco, TDK Lambda and if you want really low price have a look at Mornsun. Be care full with chinese power supplies. I have seen many cases where the module combined in product did not comply with radiated and/or conducted emission tests. You need to add extra components in order to pass emission tests.
-
Within the EU it is mandatory that your product complies with one of the relevant safety standards. If you can not prove that your product meets these safety standards, then it is forbidden to sell these products within the EU. The construction of a flyback converter is critical for safety in particular when it is powered from the mains. If you have sold products where you did not perform a safety assessment, then it might have legal impact.
The same applies for EMI/EMC. You need to verify that your product meets EMC standards. You are not allowed to sell your product without testing. EMI certification by a lab can easily cost 10K. The safety assessment you can do your self, but you need to have experience with this
Another thing to take into account is that custom designed transformers usually require minimum order quantities (>1000?). So for this reason if your sales volumes are low it is probably better to keep using modules of Recom, Traco, TDK Lambda and if you want really low price have a look at Mornsun. Be care full with chinese power supplies. I have seen many cases where the module combined in product did not comply with radiated and/or conducted emission tests. You need to add extra components in order to pass emission tests.
if i use a module like recom or hi-link, those who are certified and verified... will i need to get testing again? or is it enough?
please look at above circuit where I used and put all input protection possible for ac-dc module. besides that i don't think there is much to do. please check
-
Hi
I have following remarks regarding your flyback circuit:
1) You need to know the leakage inductance for proper dimensioning of your RCD clamp. Leakage inductance is completely determined by construction of your transformer!
2) Does your product belong to class 1 or class 2 safety class?
3) As always with reference circuits, you need to spend additional thoughs about EMI filtering. There is a big chance that this design will fail conducted emission tests. There is a big chance that the 0.33nF capacitor is not sufficient to pass these tests.
4) I don't see any surge protection at the input. All EMI standards have some form of surge testing at mains.
-
You spend so much money on the AC power supply and then you go with some SamYoung electrolytic caps ... at least that's what I think they are... can't even read a series on them, so who knows what they are. Maybe NXP because it's the only yellow series on lcsc ... but they print the series on the label on that one.
Why would you even need 3300uF worth of capacitance, aren't you using buck regulators running at high switching frequency to produce 5v and 3.3v? Not sure it makes sense to have so much capacitance...
1200-1500uF 16v solid capacitors from good brands are like 30-50 cents each
-
Hi
I have following remarks regarding your flyback circuit:
1) You need to know the leakage inductance for proper dimensioning of your RCD clamp. Leakage inductance is completely determined by construction of your transformer!
2) Does your product belong to class 1 or class 2 safety class?
3) As always with reference circuits, you need to spend additional thoughs about EMI filtering. There is a big chance that this design will fail conducted emission tests. There is a big chance that the 0.33nF capacitor is not sufficient to pass these tests.
4) I don't see any surge protection at the input. All EMI standards have some form of surge testing at mains.
the design was automatically done by power.com using innoswitch3 after i gave them the specs needed. however, please look at my circuit in attachment for input protection for a Mornsun (or Hi-link) power module. it has all recommended input protections done.
as i mentioned, i have very simple way of doing stuff. i designed this awesome power supply around recom power module (+ my own buck regulator circuits after it) and had only 5 in stock as test batch. all sold instantly even without me advertising it. i made a quality power supply for the market which demands it. it is for sega dreamcast console... a true better replacement of original power supply which excels at everything and provide better performance.
i plan to make this and sell it via my personal website + 2 big retailers in the small niche market (retro game consoles). absolutely no certification or paid tests will be done... i just don''t have enough money to do them. these retailers never asked for anything either.
maybe what you guys say apply when i want it to be soled at a bigger level or more mainstream... but this niche i don;t think it would matter.
You spend so much money on the AC power supply and then you go with some SamYoung electrolytic caps ... at least that's what I think they are... can't even read a series on them, so who knows what they are. Maybe NXP because it's the only yellow series on lcsc ... but they print the series on the label on that one.
Why would you even need 3300uF worth of capacitance, aren't you using buck regulators running at high switching frequency to produce 5v and 3.3v? Not sure it makes sense to have so much capacitance...
1200-1500uF 16v solid capacitors from good brands are like 30-50 cents each
caps are samyoung NXH series: https://www.lcsc.com/product-detail/Aluminum-Electrolytic-Capacitors-Leaded_SamYoung-Electronics-NXH-25V3300-16-25_C359208.html (https://www.lcsc.com/product-detail/Aluminum-Electrolytic-Capacitors-Leaded_SamYoung-Electronics-NXH-25V3300-16-25_C359208.html)
not bad ones, 105 degrees 10k hours low esr. i needed big caps to eliminate last bit of noise. i saw them being used in apple chargers + did research and read about their specs before using them. my go-to for good quality and cheap were Lelon RZW but these were better.
i think if i enhanced the layout just a little more i will get better result without big caps... someone told me so after giving him the layout and a unit, he said i need to let the return current be forced to return to output caps negative side first then all the way to source...instead of having ground vias everywhere like i do now. plus i have 2nd stage filtering which i think can be eliminated as well.
i will try his suggestion in my next project which is saturn psu, and if it worked better then i will revise this design to make it better.
i did use some good low esr solid polymer caps but weren't enough for 3.3v rail at 3amps due to layout not fully optimized. thus bigger caps were the compromise i did to solve it for that version and it did.
-
Which polifuse you plan to use? Proper selection of them could be challenging 8)
Good quality once can costs more than all other stuff (including HT-Link module). Cheaper one could trip in short circuit case after all PSU will burned out :-//
Plain fuses here could be safer.
-
They're probably used in apple chargers because iPhones can negotiate voltages higher than 5v, so they needed a 25v capacitor I guess.. you don't.
On 5v and 3.3v you could use 6.3v rated or 10v rated solid capacitors...
These NXH 3300/25v are 13mOh esr, 3.6A ripple current in 16x25 package...
Former Samxon, now X-Con / Man Yue Tech 1500uF 10v ULR series 8x16 solid capacitors are 10 mOhm esr, 5.9A ripple current and they're 10 cents each at lcsc : https://www.lcsc.com/product-detail/Solid-Capacitors_Man-Yue-Tech-ULR158M1AF16RR_C840181.html (https://www.lcsc.com/product-detail/Solid-Capacitors_Man-Yue-Tech-ULR158M1AF16RR_C840181.html)
Aishi SPZ 1500 / 6.3v 1500 6.3v has 10mOhm / 5.4A current and it's 15 cents each : https://www.lcsc.com/product-detail/Solid-Capacitors_AISHI-Aihua-Group-SPZ0JM152F11O00RAXXX_C160193.html (https://www.lcsc.com/product-detail/Solid-Capacitors_AISHI-Aihua-Group-SPZ0JM152F11O00RAXXX_C160193.html)
Apaq 1500/6.3v 7mOhm 6.1A 10x11.5mm 3000h @ 105c are around 25 cents each : https://www.lcsc.com/product-detail/Solid-Capacitors_APAQ-Tech-6R3AREP152M10A2T_C2681208.html (https://www.lcsc.com/product-detail/Solid-Capacitors_APAQ-Tech-6R3AREP152M10A2T_C2681208.html)
They're 2000h but the lifetime rating of solid capacitors is calculated differently than electrolytics... you double the lifetime with every 10c drop on electrolytics, while with solid capacitors the formula is different, something like L = L orig x 10^ (Tm-Ta)/20
So for example 10k@105 electrolytic at 65c ambient is 20k@95, 40k@85, 80k@75, 160k@65c and a 2000h solid capacitor is 2000 x 10^ (105-65)/20 = 2000x10^2 = 2000 x 100 = 200,000 hours
-
Which polifuse you plan to use? Proper selection of them could be challenging 8)
Good quality once can costs more than all other stuff (including HT-Link module). Cheaper one could trip in short circuit case after all PSU will burned out :-//
Plain fuses here could be safer.
chosen components so far:
CMC: RC212-0.5-10M (https://www.digikey.com/en/products/detail/schaffner-emc-inc/RC212-0-5-10M/11687459)
fuse: BK250-400-SZ (https://www.lcsc.com/product-detail/Resettable-Fuses_Brightking-BK250-400-SZ_C522962.html) a bit higher than required?
resistor: YAGEO PNP300JR-73-6R8 (https://www.lcsc.com/product-detail/Through-Hole-Resistors_YAGEO-PNP300JR-73-6R8_C1763209.html)
x cap: PANASONIC ECQUAAF224K (https://www.lcsc.com/product-detail/Suppression-Capacitors_PANASONIC-ECQUAAF224K_C99029.html)
y cap: TDK CD45-E2GA102M-VKA (https://www.lcsc.com/product-detail/Suppression-Capacitors_TDK-CD45-E2GA102M-VKA_C340633.html)
varistor: Brightking 561KD14 (https://www.lcsc.com/product-detail/Varistors_Brightking-561KD14_C78355.html)
still not final though.
They're probably used in apple chargers because iPhones can negotiate voltages higher than 5v, so they needed a 25v capacitor I guess.. you don't.
On 5v and 3.3v you could use 6.3v rated or 10v rated solid capacitors...
These NXH 3300/25v are 13mOh esr, 3.6A ripple current in 16x25 package...
Former Samxon, now X-Con / Man Yue Tech 1500uF 10v ULR series 8x16 solid capacitors are 10 mOhm esr, 5.9A ripple current and they're 10 cents each at lcsc : https://www.lcsc.com/product-detail/Solid-Capacitors_Man-Yue-Tech-ULR158M1AF16RR_C840181.html (https://www.lcsc.com/product-detail/Solid-Capacitors_Man-Yue-Tech-ULR158M1AF16RR_C840181.html)
Aishi SPZ 1500 / 6.3v 1500 6.3v has 10mOhm / 5.4A current and it's 15 cents each : https://www.lcsc.com/product-detail/Solid-Capacitors_AISHI-Aihua-Group-SPZ0JM152F11O00RAXXX_C160193.html (https://www.lcsc.com/product-detail/Solid-Capacitors_AISHI-Aihua-Group-SPZ0JM152F11O00RAXXX_C160193.html)
Apaq 1500/6.3v 7mOhm 6.1A 10x11.5mm 3000h @ 105c are around 25 cents each : https://www.lcsc.com/product-detail/Solid-Capacitors_APAQ-Tech-6R3AREP152M10A2T_C2681208.html (https://www.lcsc.com/product-detail/Solid-Capacitors_APAQ-Tech-6R3AREP152M10A2T_C2681208.html)
They're 2000h but the lifetime rating of solid capacitors is calculated differently than electrolytics... you double the lifetime with every 10c drop on electrolytics, while with solid capacitors the formula is different, something like L = L orig x 10^ (Tm-Ta)/20
So for example 10k@105 electrolytic at 65c ambient is 20k@95, 40k@85, 80k@75, 160k@65c and a 2000h solid capacitor is 2000 x 10^ (105-65)/20 = 2000x10^2 = 2000 x 100 = 200,000 hours
X-Con, SamXon, Man Yue Tech, Aishi... do you recommend these brands?
I will definitely use solid caps in next revision... actually in my current project (saturn psu) i am using ceramics + solid polymers at output (+ one small 10u elec for damping), for switchers input i use ceramics + one sold cap (270u) and the main output from the module is CLC filter and the caps are elec. caps
for saturn, 5v is main rail with 2 amps.. right now i put 5 22u 1210 ceramics + 3x470u polymers + one 10u elec to help with damping a bit.
-
The solid capacitor division of Samxon was branded / named X-Con ... both brands are owed by Man Yue : https://www.manyue.com/02about06.html (https://www.manyue.com/02about06.html) - so all three are same thing.
Samxon has a decent reputation, the capacitors are used in Corsair power supplies and other brands, the solid capacitors are used often on video cards ... for example here they are on a nvidia gtx 970 card : https://www.reddit.com/r/AskElectronics/comments/122b95q/anyone_know_the_exact_capacitor_on_this_msi_gtx/ (https://www.reddit.com/r/AskElectronics/comments/122b95q/anyone_know_the_exact_capacitor_on_this_msi_gtx/)
Apaq capacitors are used a lot on Asus motherboards on VRMs, I think also on Gigabyte boards and Asrock motherboards... for example you can see the logo all over this Asrock board : https://www.techpowerup.com/review/asrock-b550-pg-riptide/3.html (https://www.techpowerup.com/review/asrock-b550-pg-riptide/3.html) or on this Gigabyte board https://www.gigabyte.com/Motherboard/B550M-AORUS-PRO-P-rev-12#kf (https://www.gigabyte.com/Motherboard/B550M-AORUS-PRO-P-rev-12#kf)
Aishi are less common, it's more popular inside led lightning, they're less known for solid capacitors
-
The solid capacitor division of Samxon was branded / named X-Con ... both brands are owed by Man Yue : https://www.manyue.com/02about06.html (https://www.manyue.com/02about06.html) - so all three are same thing.
Samxon has a decent reputation, the capacitors are used in Corsair power supplies and other brands, the solid capacitors are used often on video cards ... for example here they are on a nvidia gtx 970 card : https://www.reddit.com/r/AskElectronics/comments/122b95q/anyone_know_the_exact_capacitor_on_this_msi_gtx/ (https://www.reddit.com/r/AskElectronics/comments/122b95q/anyone_know_the_exact_capacitor_on_this_msi_gtx/)
Apaq capacitors are used a lot on Asus motherboards on VRMs, I think also on Gigabyte boards and Asrock motherboards... for example you can see the logo all over this Asrock board : https://www.techpowerup.com/review/asrock-b550-pg-riptide/3.html (https://www.techpowerup.com/review/asrock-b550-pg-riptide/3.html) or on this Gigabyte board https://www.gigabyte.com/Motherboard/B550M-AORUS-PRO-P-rev-12#kf (https://www.gigabyte.com/Motherboard/B550M-AORUS-PRO-P-rev-12#kf)
Aishi are less common, it's more popular inside led lightning, they're less known for solid capacitors
I will add them to my list of accepted brands then, first time i know they are used in such very high end stuff!
for saturn as i said i used 5x 22u 1210 x7r caps + 3x 470u polymer 7mOhm Lelon. do you think i am over-doing it? notice that saturn psu will have better routing and layout as seen in attached images... still not complete though. I did a forced ground routing to caps negative terminals and the bottom ground pour (hidden in images) not connected to ground connections at output to prevent current from going away from caps negatives... but rather connected up near the main ac-dc module itself.
i will see after Eid how stuff is gonna be and will get a small prototype
if it is fine, then i will do a revised edition of DC one to be like this with fewer caps and more solid caps in general + better layout. I could also try hi-link ac dc module.
-
for saturn as i said i used 5x 22u 1210 x7r caps + 3x 470u polymer 7mOhm Lelon. do you think i am over-doing it? notice that saturn psu will have better routing and layout as seen in attached images... still not complete though. I did a forced ground routing to caps negative terminals and the bottom ground pour (hidden in images) not connected to ground connections at output to prevent current from going away from caps negatives... but rather connected up near the main ac-dc module itself.
i will see after Eid how stuff is gonna be and will get a small prototype
if it is fine, then i will do a revised edition of DC one to be like this with fewer caps and more solid caps in general + better layout. I could also try hi-link ac dc module.
Without knowing the maximum output current on each voltage and what switching regulators you plan to use, I really can't tell if the layout is good.
But most likely you don't need X7R capacitors, especially in that big capacitance value, as they would be expensive.
Just paralleling capacitors to reduce ripple is ok, but you'd get more results with some filters like capacitor - inductor - capacitor , or you could get less noise if you go with a 2 phase dc-dc converter
Also, considering the small size of the board and the low volume of boards you may sell and high markup, it may be worth going with a 4 layer board as it wouldn't cost more than maybe a couple dollars extra per board. Then you'd be able to have a whole inner layer and most of the bottom as ground and use top and some of the bottom for traces.
Some random google searches point to being several revisions , some with 9v instead of 12v, some with 3.3v instead of 5v... you'll have to account for that. seems like max 21w in total (they use a top202yai which is advertised as 15-30w in the original psu shown here https://www.pixelrefresh.com/resaturn-psu-review-when-your-sega-saturn-power-unit-dies/ (https://www.pixelrefresh.com/resaturn-psu-review-when-your-sega-saturn-power-unit-dies/) ) or something in that range...
The replacement psu in the link above used jumpers for selection, I'd consider using some elegant surface mount slide switches or dip switches instead of jumpers
-
for saturn as i said i used 5x 22u 1210 x7r caps + 3x 470u polymer 7mOhm Lelon. do you think i am over-doing it? notice that saturn psu will have better routing and layout as seen in attached images... still not complete though. I did a forced ground routing to caps negative terminals and the bottom ground pour (hidden in images) not connected to ground connections at output to prevent current from going away from caps negatives... but rather connected up near the main ac-dc module itself.
i will see after Eid how stuff is gonna be and will get a small prototype
if it is fine, then i will do a revised edition of DC one to be like this with fewer caps and more solid caps in general + better layout. I could also try hi-link ac dc module.
Without knowing the maximum output current on each voltage and what switching regulators you plan to use, I really can't tell if the layout is good.
But most likely you don't need X7R capacitors, especially in that big capacitance value, as they would be expensive.
Just paralleling capacitors to reduce ripple is ok, but you'd get more results with some filters like capacitor - inductor - capacitor , or you could get less noise if you go with a 2 phase dc-dc converter
Also, considering the small size of the board and the low volume of boards you may sell and high markup, it may be worth going with a 4 layer board as it wouldn't cost more than maybe a couple dollars extra per board. Then you'd be able to have a whole inner layer and most of the bottom as ground and use top and some of the bottom for traces.
Some random google searches point to being several revisions , some with 9v instead of 12v, some with 3.3v instead of 5v... you'll have to account for that. seems like max 21w in total (they use a top202yai which is advertised as 15-30w in the original psu shown here https://www.pixelrefresh.com/resaturn-psu-review-when-your-sega-saturn-power-unit-dies/ (https://www.pixelrefresh.com/resaturn-psu-review-when-your-sega-saturn-power-unit-dies/) ) or something in that range...
The replacement psu in the link above used jumpers for selection, I'd consider using some elegant surface mount slide switches or dip switches instead of jumpers
switchers are AP62300, switching frequency is fixed 750khz. 5v is at 2 amps while 3.3v is so much lower, most likely just half an amp or so. i already have circuit for 9v or 12v selection but it is not shown in the images, using jumpers for now since people here advised me previously that sliding switches do not handle high current. the current need to pass the switch\jumper in this design.
i think this these parallel low esr caps + good layout shown i can get low noise performance. going 4 layers is a viable option but first i will test normal 2 layer board to see first prototype result and then i judge what is going to happen.
looks like i got convinced on using Hi-Link power module suggested here instead of mornsun one.... due to price most likely. can't beat 2.5$ for quantity of 100! especially that in both cases i need to do the input protection myself which i did.
the replacement psu you linked requires external adapter as you know. they always suggest high powered adapter but really the saturn is rated at about 12w so a 15w power module is good enough for it. testing will make sure this is correct too.
EDIT:
a had a stupid idea for the DC power supply to use 2 parallel ac-dc modules (mornsun ls15). 2 rated at 15W to be 30W. both modules + input protection would be less than high quality recom one. is this solution reasonable or as i said, stupid?
-
CMC: RC212-0.5-10M
fuse: BK250-400-SZ a bit higher than required?
resistor: YAGEO PNP300JR-73-6R8
x cap: PANASONIC ECQUAAF224K
y cap: TDK CD45-E2GA102M-VKA
varistor: Brightking 561KD14
Regarding Y1 capacitors. You can also pick 2 SMD Y2 capacitors and place in series (which is equivalent to Y1 cap). Have a look at safety capacitors from Johanson. You need to verify with the applicable safety standards but I think you need a bleeder resistor with X-cap. You need to investigate in further detail the inrush current of Mornsun module. I think the module you selected has no soft start. I see inrush currents of 20A in datasheet. You need to ensure that resistor/fuse can handle this. Since you have no way to perform conducted emission and other EMC tests, you should follow the recommendations in datasheet. Datasheet recommends input choke.
-
CMC: RC212-0.5-10M
fuse: BK250-400-SZ a bit higher than required?
resistor: YAGEO PNP300JR-73-6R8
x cap: PANASONIC ECQUAAF224K
y cap: TDK CD45-E2GA102M-VKA
varistor: Brightking 561KD14
Regarding Y1 capacitors. You can also pick 2 SMD Y2 capacitors and place in series (which is equivalent to Y1 cap). Have a look at safety capacitors from Johanson. You need to verify with the applicable safety standards but I think you need a bleeder resistor with X-cap. You need to investigate in further detail the inrush current of Mornsun module. I think the module you selected has no soft start. I see inrush currents of 20A in datasheet. You need to ensure that resistor/fuse can handle this. Since you have no way to perform conducted emission and other EMC tests, you should follow the recommendations in datasheet. Datasheet recommends input choke.
i do have common mode choke, what other choke you mentioned? you mean "LDM"?
i will look into having 2 y caps in series for sure.
i tried applying "Application circuit 3——Universal system recommended circuits for indoor industrial environment".
note 2 says:
Note 2: According to the certification requirements, the X capacitor needs to be connected in parallel with the bleeder resistance, the recommended
resistance value is less than 2.5MΩ, and the actual need to be selected according to the certification standard.
so it is just a resistor, say 1 mega ohm 1 watt or so, in parallel with x cap? seems easy and cheap.
-
Please note that there the bleeder resistor selection must meet requirements in safety standards. Resistor value selection is base d on discharge time in safety standard.
common mode chokes are for damping common mode currents. The Mornsun power supply draws impulse input currents. For this reason you often see a choke (LDM) in series with input. This way the impulse currents are filtered by input capacitor. You need to pick the application note section for indoor class B emission. Please also note that the Mornsun application section for indoor has no surge protection. My advice is add surge protection! The mornsun power supply does not specify switching frequency. You need to select common chokes matching with mornsun power supply. Hope this helps
-
Please note that there the bleeder resistor selection must meet requirements in safety standards. Resistor value selection is base d on discharge time in safety standard.
common mode chokes are for damping common mode currents. The Mornsun power supply draws impulse input currents. For this reason you often see a choke (LDM) in series with input. This way the impulse currents are filtered by input capacitor. You need to pick the application note section for indoor class B emission. Please also note that the Mornsun application section for indoor has no surge protection. My advice is add surge protection! The mornsun power supply does not specify switching frequency. You need to select common chokes matching with mornsun power supply. Hope this helps
i was hoping to design input protection circuit which suits not just mornsun module but others like hi-link ones. more of a universal input protection which can work for most options.
adding a series inductor for low current of 0.5A is not a big issue, they specify 1.2mH meaning about 1200uH? many of them on LCSC like these 2:
https://www.lcsc.com/product-detail/Power-Inductors_COILMX-MACM5045-102_C19076710.html (https://www.lcsc.com/product-detail/Power-Inductors_COILMX-MACM5045-102_C19076710.html)
https://www.lcsc.com/product-detail/Power-Inductors_PROD-Tech-PSPHAQ127-102M_C2983085.html (https://www.lcsc.com/product-detail/Power-Inductors_PROD-Tech-PSPHAQ127-102M_C2983085.html)
what surge protection is to be added in your opinion? I mean what more am I missing to make the circuit very safe and robust?
I could look for mornsun\meanwell recommendation and follow it with using other brands like hi-link. since most of it is the same, even switching frequency is similar which is on the lower end.
-
switchers are AP62300, switching frequency is fixed 750khz. 5v is at 2 amps while 3.3v is so much lower, most likely just half an amp or so. i already have circuit for 9v or 12v selection but it is not shown in the images, using jumpers for now since people here advised me previously that sliding switches do not handle high current. the current need to pass the switch\jumper in this design.
i think this these parallel low esr caps + good layout shown i can get low noise performance. going 4 layers is a viable option but first i will test normal 2 layer board to see first prototype result and then i judge what is going to happen.
looks like i got convinced on using Hi-Link power module suggested here instead of mornsun one.... due to price most likely. can't beat 2.5$ for quantity of 100! especially that in both cases i need to do the input protection myself which i did.
the replacement psu you linked requires external adapter as you know. they always suggest high powered adapter but really the saturn is rated at about 12w so a 15w power module is good enough for it. testing will make sure this is correct too.
EDIT:
a had a stupid idea for the DC power supply to use 2 parallel ac-dc modules (mornsun ls15). 2 rated at 15W to be 30W. both modules + input protection would be less than high quality recom one. is this solution reasonable or as i said, stupid?
You're not switching the voltage, you're switching between two resistors on the feedback of the switching regulator.
For example, if you stay with AP63200, the datasheet recommends 31.6k and 10k for 3.3v out, and 52.3k and 10k for 5v out.
So you could have 31.6k in series with a 20.7k ohm resistor (or a 20.5k if you want to stick to E48 resistors and get ~4.97v out) and if you want 3.3v out, the jumper/ slide switch simply shorts out the 20.7k resistor creating a 0 ohm path, so the regulator will only see 31.6k and 10k - With a jumper there's a small downside as in if the jumper is missing, the regulator defaults to 5v instead of 3.3v, there's less risk of damaging a console if you default to outputting the lower voltage.
With a slide switch, you could use a double slide switch and have a status led for each voltage light up, depending on the position of the slide switch only one of the leds would light up... so user could set the slide switches before connecting the cable to the unit, see the voltage leds light up and be sure he got it right, then turn off power and connect cable to console.
As for 12v/9v out obviously won't get 12v out with 12v in, but you could just use a 15v DC out converter (your regulators are good up to 18v in) or most good AC-DC converters will have a TRIM / ADJ pin that you could take advantage of to make the AC/DC converter output 12.5v ... 13.5v instead of 12v
You can get 15v 40w open frame power supplies for 8.5$ a piece if you order at least 5 : https://www.digikey.com/en/products/detail/mornsun-america-llc/LO45-10B15/13168116 (https://www.digikey.com/en/products/detail/mornsun-america-llc/LO45-10B15/13168116)
or sealed ones for 8-11$ : https://www.digikey.com/short/vzn9v3ct (https://www.digikey.com/short/vzn9v3ct)
AP63200 is fine, relatively cheap ... if you want to optimize some more you could use buck regulators with 2 or more outputs.
For example, Richtek RT2723 is around 1$ on lcsc, around 2.12 EUR if you get 10 at Mouser , around 2.4$ at Digikey if you buy 10, but has 3 outputs, supporting 3A/2A/2A continuously , or maximum 3.5A/2.5A/2.5A
Digikey : https://www.digikey.com/en/products/detail/richtek-usa-inc/RT7273GQW/3986811 (https://www.digikey.com/en/products/detail/richtek-usa-inc/RT7273GQW/3986811)
Mouser : https://eu.mouser.com/ProductDetail/Richtek/RT7273GQW?qs=amGC7iS6iy9%2Fyt7eO0%252B6kw%3D%3D (https://eu.mouser.com/ProductDetail/Richtek/RT7273GQW?qs=amGC7iS6iy9%2Fyt7eO0%252B6kw%3D%3D)
LCSC : https://www.lcsc.com/product-detail/DC-DC-Converters_Richtek-Tech-RT7273GQW_C3028966.html (https://www.lcsc.com/product-detail/DC-DC-Converters_Richtek-Tech-RT7273GQW_C3028966.html)
See example at page 9 in datasheet... it's a more pain in the ass footprint, and you'd have a bunch more passives (resistors and ceramic capacitors), but you would get 3.3v , 5v and 9v with a single chip and could have 12v straight from the ac - dc converter.
You could also get some inspiration from the evaluation board : https://www.richtek.com/m/~/media/EVB%20PDF%20File/EVB_RT7273GQW/EVB_RT7273GQW-00_EN.pdf (https://www.richtek.com/m/~/media/EVB%20PDF%20File/EVB_RT7273GQW/EVB_RT7273GQW-00_EN.pdf)
-
You're not switching the voltage, you're switching between two resistors on the feedback of the switching regulator.
i know about this but i was referring to the solution where i have 12v input, this way i need 15v input.
I can use this module: https://www.lcsc.com/product-detail/Power-Modules_HI-span-style-background-color-ff0-LINK-span-HLK-15M15C_C5120968.html (https://www.lcsc.com/product-detail/Power-Modules_HI-span-style-background-color-ff0-LINK-span-HLK-15M15C_C5120968.html)
which outputs 15v to deliver it to your suggested triple buck IC, which I really found it a month ago when I was searching. I don't really know if this total price will be lower than my own using AP62300.
meanwell irm-20-15 is +8.3$ for 100 quantity while above module is about 2.5$. meanwell is better name brand + does not require external protection components while hi-link does. even mornsun module LS15-23B15DR3 requires external components.
mornsun LD15-23B15R2-M seems cheaper and does not require much external components.
so now i have 4 options:
1- use very cheap Hi-link module and build all input protection myself.
2- use Mornsun LS15-23B15DR3 module and build all input protection myself, similar to option 1.
3- use Mornsun LD15-23B15R2-M module, just put a mov and input series resistor as everything else is inside.
4- use Meanwell module which has everything built in.
money-wise, full input circuit protection is going to be around 1$ or so.
rough estimate for options in 100 quantity:
1 = 3.5-4$.
2 = 6$
3 = 8$
4 = 9-10$
For example, Richtek RT2723 is around 1$ on lcsc, around 2.12 EUR if you get 10 at Mouser , around 2.4$ at Digikey if you buy 10, but has 3 outputs, supporting 3A/2A/2A continuously , or maximum 3.5A/2.5A/2.5A
Using Richtech one, Vout1 = 5v, Vout2 = 3.3v, Vout3 = 9 or 12v by switching feedback resistor. certainly can be done but the issue is that the power supply area is a rectangle with about 50mm width or less. no big room but will see if i can make it work.
evaluation board used relatively cheap inductor, 4.7uH with about 23mOhm resistance. I prefer using highest switching frequency but lower resistance inductors will be big in size. achieving low ripple is important but also low heat. looks like for 2.2 mhz i need 600kohm resistor. what do you use in such situations to achieve smallest ripple available with good thermals?
for filtering output caps, i could still use the 22uF 1210 X7R ones I used before... plus some polymers in parallel. having lots of ceramics in parallel can be achieved in small spaces.
there is the compensation which i am always afraid of. they suggest 4.7nf cap in series with 20kohm resistor for the output caps of 44uF ceramic. they suggest doing a ratio to reduce it for 22uf output caps it should be 10k resistor. this way if i want 4x22u = 88u caps + 470u poly it would be very small compensation cap... more like 1.58k ohm or something. i could not find an equation to do it.
it is fair to say that I need more filtering caps for the big amps rail of 5v 2a, the others 3.3v at 0.6a or 12v\9v at very low amps probably won't require more than 2x22u ceramics.
__________
I am kinda confused now since I wanted this PSU to sell for max of 60$. if i go with best options:
meanwell irm-20-15: 8.5$
richtek switcher: 0.8 (assume all from lcsc, which now is just 24 units in stock)
ceramic caps: ~0.3
other caps: 0.2
resistors: 0.1
connectors: 2 or so
pcb: 7.5
inductors: 0.6
total = 20$ for 100 quantity. more for less quantity.
it can be sold for 60$ and even for 50$ but if i have the other options i could save more.... if you were in my place, what would you choose?
-
The HiLink doesn't have input filtering (common mode choke, ptc/ntc for inrush current limiting, fuse, x2 capacitors ... you can find all these on those open frame power supplies I mentioned) - that's how you get that cheaper.
You have to consider the old consoles output analogue signals, which may pick up the noise the switch mode psu may output back into the grid
You're not that space constrained that you couldn't just put 4 AP62300, or the fixed voltage versions of it for 3.3v and 5v (ap63205, ap63203) and a couple adjustable versions ... if you go with AP63200 / AP63201 then all your regulators would support up to 32v input and output 2A each ... if you want 3A there's AP63300 that can do 3A and it's adjustable.
and as they require much fewer passives you could afford to even buy some RF shields and put them over the regulators to further reduce switching noises ...see https://www.digikey.com/short/zrfqr7m7 (https://www.digikey.com/short/zrfqr7m7) for examples
Personally I'd put a barrel jack connector (or two, the most common two sizes 2.1 ID and 2.5 ID) and sell the kit with a mass produced certified 15v-16.5v-19.5v or even 20v / 24v laptop adapter, then all the AC switching can sit down on the floor near the socket, you just do the dc-dc conversion in the psu.
Alternatively you could have a usb type c input, and use a usb trigger ic to attempt to negotiate to 12v or 15v or 20v and you could bundle with a charger that supports usb power delivery or offer the board at a discount (ex 10-15$ off if you don't bundle the power supply) ... works also for you as shipping costs will be less if you don't bundle a heavy power supply.
with usb type c you don't have the problem of power supplies barrel connectors being different sizes (ex 2.1 ID / 5.5 OD versus 2.5 ID / 5.5 OD) but not all chargers out there can go above 12v so it's not a perfect solution, could get people buying the wrong chargers.
Without the AC-DC converter on the board, you could make the whole board smaller and panelize it to get more boards for the price.
-
The HiLink doesn't have input filtering (common mode choke, ptc/ntc for inrush current limiting, fuse, x2 capacitors ... you can find all these on those open frame power supplies I mentioned) - that's how you get that cheaper.
i know it does not, which is why i told you i need to do all input filtering myself. open frame stuff are not pcb solderable which is a requirement to me.
You have to consider the old consoles output analogue signals, which may pick up the noise the switch mode psu may output back into the grid
my psu was very low noise and ripple, image was very clear. no problem there and i want the same for saturn version.
You're not that space constrained that you couldn't just put 4 AP62300, or the fixed voltage versions of it for 3.3v and 5v (ap63205, ap63203) and a couple adjustable versions ... if you go with AP63200 / AP63201 then all your regulators would support up to 32v input and output 2A each ... if you want 3A there's AP63300 that can do 3A and it's adjustable.
AP62300 seems better choice than these. 2 of it in the saturn version fits as i send the pictures previously. 5v is maximum of 2 amps but i got the 3 amps just in case.
actually AP62200TWU here: https://www.lcsc.com/product-detail/DC-DC-Converters_Diodes-Incorporated-AP62200TWU-7_C2895288.html (https://www.lcsc.com/product-detail/DC-DC-Converters_Diodes-Incorporated-AP62200TWU-7_C2895288.html)
is very cheap, < 16.38$ for 200 units (enough for 100 boards). while 3 amps equivalent is just 17$ so i think 3 amps is better choice. this is the T version, i will have to get it instead of regular one.
and as they require much fewer passives you could afford to even buy some RF shields and put them over the regulators to further reduce switching noises ...see https://www.digikey.com/short/zrfqr7m7 (https://www.digikey.com/short/zrfqr7m7) for examples
i really never thought of this. but it is safe to say i need to test without it first as a simple prototype then see what happens.
Personally I'd put a barrel jack connector (or two, the most common two sizes 2.1 ID and 2.5 ID) and sell the kit with a mass produced certified 15v-16.5v-19.5v or even 20v / 24v laptop adapter, then all the AC switching can sit down on the floor near the socket, you just do the dc-dc conversion in the psu.
such solutions exist now, people do not like them at all. everyone wants a complete high quality universal plug-and-play solution. my DC one got the hype and people are anticipating it eagerly.
preserving same look and feel is very respected in this hobby.
so for getting the ac -dc power module built in, what do you recommend? notice that safety and heat are important but not overly obsessive... like, no certification needed just ensured performance.
in DC, i opted for recom medically rated module. i wanted meanwell irm-30-12 but it was big and i could not fit it inside, especially that i used lots of big caps and 2nd stage...etc. (would revise that for sure). but for saturn i want something cheaper
i make them with pcbway and i have no complains but i feel board price and assembly are kinda not cheap. they offered to panelize the last batch of 40 units, they did a panel of just 2 boards. i wonder if i could panelize myself and make it cheaper by a significant amount.
_____
EDIT:
one trick i could use to lower cost and save lots of space is to use a small lower power inductor for 3.3v (and for 9 and 12v if used a regulator for them):
this one i found: https://www.lcsc.com/product-detail/Power-Inductors_cjiang-Changjiang-Microelectronics-Tech-FTC252012S3R3MBCA_C5832373.html (https://www.lcsc.com/product-detail/Power-Inductors_cjiang-Changjiang-Microelectronics-Tech-FTC252012S3R3MBCA_C5832373.html)
it has 80m Ohm DCR, not very good but switching frequency is not high and current is not high at all. it has very small footprint too while being 3.3uH.
here is another one with 34mOhm: https://www.lcsc.com/product-detail/Power-Inductors_DMBJ-CD54-3R3M-3-3UH_C2826659.html (https://www.lcsc.com/product-detail/Power-Inductors_DMBJ-CD54-3R3M-3-3UH_C2826659.html)
but this one has exposed un-shielded wires...
while the one i currently use and will be used for 5v rail is: https://www.lcsc.com/product-detail/Power-Inductors_APV-APH1040T3R3M_C5349719.html (https://www.lcsc.com/product-detail/Power-Inductors_APV-APH1040T3R3M_C5349719.html)
11.8mOhm but massive 11mm one.
as for alternative,
this one: https://www.lcsc.com/product-detail/Power-Inductors_Ceaiya-CR5040-3R3N_C520346.html (https://www.lcsc.com/product-detail/Power-Inductors_Ceaiya-CR5040-3R3N_C520346.html)
and this one from sunlord: https://www.lcsc.com/product-detail/Power-Inductors_Sunlord-SWPA5040S3R3NT_C305173.html (https://www.lcsc.com/product-detail/Power-Inductors_Sunlord-SWPA5040S3R3NT_C305173.html)
both are 24mohm and very small footprint. i don't know why i hate this package!
current solution for 9v output is a 7809. don't know if i can use the same solution for 12v-9v switching with resistor switching via slide switch... lm317 is in mind but would want it to be as cheap... found this lm317: https://www.lcsc.com/product-detail/Linear-Voltage-Regulators-LDO_UMW-Youtai-Semiconductor-Co-Ltd-LM317LIPK_C3029045.html (https://www.lcsc.com/product-detail/Linear-Voltage-Regulators-LDO_UMW-Youtai-Semiconductor-Co-Ltd-LM317LIPK_C3029045.html)
it should be ok since 9v and 12v are just for PAL scart auto switching... just a signal. since for supported tvs when they read voltages of 9 or 12 they switch to scart automatically
-
it should be ok since 9v and 12v are just for PAL scart auto switching... just a signal. since for supported tvs when they read voltages of 9 or 12 they switch to scart automatically
If that's all it's used for, wouldn't just 9V work for all revisions? For that matter, maybe it would make more sense to have the main supply output 5V or 3.3V and use a small boost converter or charge pump for the 9V.
-
it should be ok since 9v and 12v are just for PAL scart auto switching... just a signal. since for supported tvs when they read voltages of 9 or 12 they switch to scart automatically
If that's all it's used for, wouldn't just 9V work for all revisions? For that matter, maybe it would make more sense to have the main supply output 5V or 3.3V and use a small boost converter or charge pump for the 9V.
not quite sure it works for all, but i read about 9 and 12 being different... aspect ratio thing.
having 5v is mail output will save me a regulator but the ripple will be high since these modules are not optimized for low ripple. they produce 150-200mv ripple but i intend to get 20mv max... i achieved that with dreamcast one, more or less.
since the module for 5v and 15v kinda same price then it will be ok for having small extra for good switcher... while cheap out for 9\12v rail.
-
as for the new saturn PSU, I decided to use Meanwell IRM-20-12 or IRM-20-15 which give 12v and 15v output respectively.
the 15v one is 2.8$ cheaper. however, it would require a regulator for it to output 12v or 9v.
I wanted to use slide switch to switch between the feedback resistors to get 9v or 12v but i remembered another jumper switch option is required at one of the output pins, to switch between 5v or 3.3v. there i guess i cannot use slide switch since it will get higher current if 5v was the choice even if there is another 5v pin near it...
if so, then i would revert back to using a jumper for 12v\9v to keep it the same...
having 15v module seems better since 2.8$ price difference is too big... i mean i am currently using a cheap chinese lm317 chip with different feedback resistor swapped by a jumper. switching back to 12v module and 7809 won't save me 2$ difference. what do you think?
besides those big stuff, the rest is just cleanup and misc. stuff.
_______
For the revised version of Dreamcast PSU, since it uses an expensive and big lead time Recom module with high quality medical rating.. i found a Meanwell equivalent which is MFM series, namely MFM-30-5 which outputs 5v. it is the cheapest of the series tied with 24v one but if i use 24v module i would need an extra buck for 5v + higher voltage caps which will be noticeably more expensive... so 5v it is... as long as my filtering caps can reduce its noise.
i use it with buck regulator (ap63357) for getting the main 3.3v rail, 5v rail is directly gotten from the module but with many polymer + ceramic caps to reduce ripple, and the 12v rail is via a boost regulator (tlv61048 + small inductor + ceramic output caps).
this saves some money, especially if i ditch the expensive input common-mode choke since i think the one inside module is enough + get a cheaper output connector alternative from alibaba (i got a sample and it works fine).
maybe i can get its price down to 75$ which will make it significantly more appealing.
-
I actually found some slide switches which can tolerate high current. 5v has 2 amps in total, so if 5v was chosen it will have 2 amps on 2 pins, roughly 1 amp per pin.
I got this:
https://www.lcsc.com/product-detail/Slide-Switches_SHOU-HAN-SS12D10G5_C7431054.html (https://www.lcsc.com/product-detail/Slide-Switches_SHOU-HAN-SS12D10G5_C7431054.html)
2 amps rated, there are 3 amps ones and up to 6 amps...
while the slide switch required for switching between feedback resistors for 12 and 9v output is significantly cheaper and available.
i think i will go with these choices.
-
If you actually trust a tiny lubrified steel ball sitting between two contacts with amps of current... and on a 7 cent part...
Still think it's best not to switch the actual voltages, switch the adjustment resistors or something like that.
There's making things cheap and then there's being ridiculous. You're planning to charge 50$ on something that costs you under 10$ to make and you're still looking where to cut costs.
-
If you actually trust a tiny lubrified steel ball sitting between two contacts with amps of current... and on a 7 cent part...
Still think it's best not to switch the actual voltages, switch the adjustment resistors or something like that.
There's making things cheap and then there's being ridiculous. You're planning to charge 50$ on something that costs you under 10$ to make and you're still looking where to cut costs.
it will cost about 20$ according to my estimates, but still good.
I don't really trust these slide switches but they are one of my choices. the LM317 circuit for 9v/12v can use a cheap one to switch feedback resistors... that is done.
the remaining is to switch between 5v and 3.3v... 5v always on, but some variations require 3.3v alongside 5v. here i need to switch voltages not feedback resistors... since 5v regulator already exist and it is on. the 3.3v regulator works but it is either switched on to the load or not.
jumper seemed best choice overall as long as slide switches are outside the picture.
another possible robust solution is a toggle switch like this one: https://www.lcsc.com/product-detail/Toggle-Switches_YUEN-FUNG-ST-0-103-A01-T000-RS_C1788488.html (https://www.lcsc.com/product-detail/Toggle-Switches_YUEN-FUNG-ST-0-103-A01-T000-RS_C1788488.html)
but the jumper is way cheaper and does the same thing... just that the switch is easier and more elegant.
what would you do?
-
You can use power switches with an EN pin , or p-channel mosfets, or ideal diodes with EN pin, and use the jumper / slide switch to pull the EN pins high or down, or to connect voltage to the gate of a mosfet or not (by default gate being pulled up or down with a high ohm resistor)
There's also solid state relays you could use...
Examples of power switches
TPS2121 , good for up to 4.5A of current : https://www.digikey.com/en/products/detail/texas-instruments/TPS2121RUXR/9859001 (https://www.digikey.com/en/products/detail/texas-instruments/TPS2121RUXR/9859001) or https://www.digikey.com/en/products/detail/texas-instruments/TPS2121RUXT/9859003 (https://www.digikey.com/en/products/detail/texas-instruments/TPS2121RUXT/9859003)
from datasheet
If both inputs are valid, CP2 is low, and PR1 is pulled high, (higher than VREF, 1.06-V typical), then IN1 is used.
If both inputs are valid, CP2 is low, and PR1 is pulled low, then the highest voltage input is used.
So put 3.3v on IN1 , 5.0v on IN2 ... pull PR1 high and you get 3.3v out , pull PR2 low and you get highest voltage of the two, which is IN2 (5.0v)
For lower currents
LM66200 dual ideal diode , 2.5A (auto switches between highest voltage) : https://www.digikey.com/en/products/detail/texas-instruments/LM66200DRLR/15856663?s=N4IgTCBcDaIDIFkBsSwAY0gLoF8g (https://www.digikey.com/en/products/detail/texas-instruments/LM66200DRLR/15856663?s=N4IgTCBcDaIDIFkBsSwAY0gLoF8g)
The auto switch won't helpful, you ignore that, connect both inputs to same voltage.
It has an EN pin that disables both inputs, so you can have two of these, one that has both inputs on 3.3v , one that has both inputs on 5.0v, and connect the outputs... and you turn off the ideal diode you don't want.
For less current, LM66100 is the single ideal diode version that does up to 1.5A : https://www.digikey.com/en/products/filter/power-management-pmic/or-controllers-ideal-diodes/ (https://www.digikey.com/en/products/filter/power-management-pmic/or-controllers-ideal-diodes/)
Same deal, has an enable pin, pull high to turn it off (it uses a p-channel mosfet, so it's on by default)
Solid state relays ... TLP241A does 2A in a optocoupler package : https://www.digikey.com/en/products/detail/toshiba-semiconductor-and-storage/TLP241A-TP1-F/6574627 (https://www.digikey.com/en/products/detail/toshiba-semiconductor-and-storage/TLP241A-TP1-F/6574627)
-
ideal diode seems good idea, found these ICs cheap on LCSC.
However, the on-resistance will have its effect. at about 0.7 amps for 3.3v rail it will be 0.7*0.7*0.091 (LM66100) = ~0.045v drop -> 3.3v rail will be 3.255v so compensation must be done... that is if it does not exceed 0.7 amps. for 5v at 2 amps, assuming 1 amp per pin with LM66200 will be 1*1*0.04 = 0.04v drop -> 4.96v total.
for 5v, if i made it 5.05v then it will be ok but will have 2 pins of 5v rail being of different voltage.. on is 5.05v and the other is 5.0v. don't know what to do with this.
by ideal diode i think they mean a mosfet switcher circuit right? so can we do it in a cheaper way + using very low resistance mosfet?
-
Unless I have a brain fart, the voltage drop is V = Current x Resistance = 0.091 x 0.7 = 0.06v ... Power is I^2 x R
I suppose you could configure the regulator to output 3.4v but probably not needed ... you're gonna have voltage drop on the wires between your psu and the console anyway, so the whole console won't be that sensitive about exact voltages...
-
Unless I have a brain fart, the voltage drop is V = Current x Resistance = 0.091 x 0.7 = 0.06v ... Power is I^2 x R
I suppose you could configure the regulator to output 3.4v but probably not needed ... you're gonna have voltage drop on the wires between your psu and the console anyway, so the whole console won't be that sensitive about exact voltages...
it was my mistake, yes drop will be 0.06v for that. still needs compensation.
however, i found this p-mosfet: https://www.lcsc.com/product-detail/MOSFETs_Diodes-Incorporated-DMP1005UFDF-7_C461046.html (https://www.lcsc.com/product-detail/MOSFETs_Diodes-Incorporated-DMP1005UFDF-7_C461046.html)
i can get 2 of it, hook some resistance from its drain to gate to make it off by default. then get the slide switch to connect ground to desired mosfet gate to make it active.
wouldn't that work as well? still cheaper and this mosfet has very small resistance so it would not affect anything.
it was inspired by this: https://www.ti.com/lit/an/slva716a/slva716a.pdf?ts=1713171404977&ref_url=https%253A%252F%252Fwww.google.com%252F (https://www.ti.com/lit/an/slva716a/slva716a.pdf?ts=1713171404977&ref_url=https%253A%252F%252Fwww.google.com%252F)
I also found these:
https://www.lcsc.com/product-detail/Power-Distribution-Switches_Diodes-Incorporated-AP22966DC8-7_C441830.html (https://www.lcsc.com/product-detail/Power-Distribution-Switches_Diodes-Incorporated-AP22966DC8-7_C441830.html)
https://www.lcsc.com/product-detail/Power-Distribution-Switches_Texas-Instruments-TPS22976NDPUR_C106796.html (https://www.lcsc.com/product-detail/Power-Distribution-Switches_Texas-Instruments-TPS22976NDPUR_C106796.html)
first is very cheap... both has 2 outputs so i can hook my 2 sources at inputs and connect both outputs together... make the slide switch activate only one output at a time.
EDIT: I looked but could not find Rload of 200-300 ohms as you mentioned. some tables has 10 ohms. i guess i will be ok.
-
I have decided to use this switcher IC: https://www.lcsc.com/product-detail/Power-Distribution-Switches_Diodes-Incorporated-AP22966DC8-7_C441830.html (https://www.lcsc.com/product-detail/Power-Distribution-Switches_Diodes-Incorporated-AP22966DC8-7_C441830.html)
please check schematic in attachment.
basically, i shorted the 2 inputs since the switch is supposed to switch between 2 power sources to deliver to one output.
will this cause problems like shorting? I've put some soft-start caps to make it a bit gentle.
-
This switch include discharge resistor on each output channel that turned on when channel disabled (as followed from schematic in datasheet). You short output from both channels, so one of discharge resistor always will be connected parallel to output. Its value is 220-300 Ohm. You can use this switch if you can tolerate such surplus load.
-
This switch include discharge resistor on each output channel that turned on when channel disabled (as followed from schematic in datasheet). You short output from both channels, so one of discharge resistor always will be connected parallel to output. Its value is 220-300 Ohm. You can use this switch if you can tolerate such surplus load.
worst case is 5v for 300 ohms = 16.7 mA. very tiny, won't make an effect.
however will this circuit yeild any dangerous issue like shorting?
a simpler solution is to use such a switch like this one: https://www.lcsc.com/product-detail/Toggle-Switches_YUEN-FUNG-ST-0-103-A01-T000-RS_C1788488.html (https://www.lcsc.com/product-detail/Toggle-Switches_YUEN-FUNG-ST-0-103-A01-T000-RS_C1788488.html)
i want one which does not have luggs and stuff, but overall it is more expensive though, cheapest ever is a jumper but it is not elegant
-
however will this circuit yeild any dangerous issue like shorting?
I see no danger. It should work.