Author Topic: Bench top PS for testing advice.  (Read 1927 times)

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Offline Serge125Topic starter

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Bench top PS for testing advice.
« on: January 12, 2021, 08:30:24 pm »
Hi all!!

   Ok red the part before asking and what I'm asking for has way too much answers and just can't filter it all so decided to ask here. I would like to buy a bench top power supply to be used to fix electronics (just the basic all around home stuff; receivers, computers (old Comodore etc...), lcd/led tvs etc...you know what I mean) and I want to buy it at Amazon. Yeah I could buy a very expensive one but don't have that type of cash I just want one that is flexible at doing what I need BUT not end up to a point that I need something a bit bigger later on, just an all around good ps.

THANKS!!
 

Offline bdunham7

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Re: Bench top PS for testing advice.
« Reply #1 on: January 12, 2021, 08:54:17 pm »
Are you looking for a low voltage DC power supply or an AC isolated power supply?  If DC, just one output or several?  Many devices require several voltages internally to function.

There's no way to future proof as there will always be some case that requires more than you have.  I would look for a higher-quality used one, but if you want new from Amazon, you can get those cheap digital switching single-output models and then get another one later if you need more than one output.

Genuine Kaiweets:

https://www.amazon.com/KAIWEETS-Adjustable-Switching-Regulated-Interface/dp/B085S34NNW/ref=sr_1_3?dchild=1&keywords=kaiweets+power+supply&qid=1610484680&sr=8-3

Kaiweets clone in white:

https://www.amazon.com/Dr-meter-4-Digital-Multifuncitonal-Switching-Laboratory/dp/B07S1NPF5G/ref=sr_1_2?dchild=1&keywords=dr+meter+power+supply&qid=1610484622&sr=8-2

Or, if you can afford more and don't like cheap junk, this one probably would meet  your needs for years:

https://www.amazon.com/Siglent-Technologies-SPD3303X-Triple-Output/dp/B01410O424/ref=sr_1_1_sspa?dchild=1&keywords=Siglent+Technologies+SPD3303X-E&qid=1610484838&s=industrial&sr=1-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzVUdJM0FIWExPNk5EJmVuY3J5cHRlZElkPUEwMzcwOTMzMkhQSFk4RUwzTko4RiZlbmNyeXB0ZWRBZElkPUEwNDMxODUxMVBIMEQwV0lWVlAyTSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline ledtester

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Re: Bench top PS for testing advice.
« Reply #2 on: January 12, 2021, 09:21:07 pm »
I just want one that is flexible at doing what I need BUT not end up to a point that I need something a bit bigger later on

If you spend a lot of time in electronics it is likely you will need multiple power supplies. Also, some kinds of power supplies are better for certain applications than others.

A 30V/3 or 5A linear power supply is a good place to start. Another good option is a dual output supply like this:

https://www.amazon.com/Tekpower-TP3003D-3-Digital-Variable-Linear-type/dp/B00HV12TZ0/

which can be put in series or parallel for more voltage/current. Also has a 5V output.
 
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Offline J-R

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Re: Bench top PS for testing advice.
« Reply #3 on: January 13, 2021, 10:39:17 pm »
I don't think you would want to go any lower budget than the Korad KA3005P https://www.amazon.com/KORAD-KA3005P-Programmable-Precision-Adjustable/dp/B0085QLNFM

10mV and 1mA display and USB for a computer connection.  I think the listing is incorrect about the 0.001V resolution.  Fan noise might be a concern, but you can replace it.

Not to throw shade on the other suggestions, but I think the output on/off button is very critical and the coarse/fine knobs are obnoxious in my opinion.
« Last Edit: January 13, 2021, 10:45:34 pm by J-R »
 
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Online nctnico

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Re: Bench top PS for testing advice.
« Reply #4 on: January 13, 2021, 10:52:51 pm »
Yes. Fine/coarse knobs suck big time. Another option are the Gophert power supplies. Small, fanless and they do work just fine. I just bought a whole bunch of these to use as variable voltage, current limited high power wall warts and they do well for that purpose.

To the OP:
Another concern is whether to go for a switching or linear power supply. If you want to use an oscilloscope to make measurements then you should definitely go for a linear power supply. A switching power supply generally produces way too much electrical noise to allow making good oscilloscope measurements.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline Serge125Topic starter

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Re: Bench top PS for testing advice.
« Reply #5 on: January 25, 2021, 06:16:41 pm »
Hi all!!!

   Sorry for not responding didn't have much time and not always on my computer. Yeah I just need DC for now don't work too much with AC and to how may outputs well for now single would do (BTW is there a you tube vid that would show how to use multiple outputs so I could make a final decision). I don't fix electronics every day just from time to time when I get a chance to do so. Yep I saw a review on YouTube on the "DC Power Supply Variable 30V 10A, KAIWEETS 4-Digit Large Display Adjustable Switching Regulated Power Supply with USB Interface" and it looks like a good one for me to start with. I know that the more expensive ones are better but I don't have that cash to buy them I just want to get what I can afford that will just get the job done. Again thanks for all the help!!!

Serge
 

Offline l0rd_hex

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Re: Bench top PS for testing advice.
« Reply #6 on: March 01, 2021, 04:01:34 am »
Howdy Serge125,

Did you buy this PS, if so how do you like it so far?
"I haven't paid taxes in six years, and I'm not getting busted by a damn sandwich." - Benjamin Franklin
 

Offline Zlotnik

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Re: Bench top PS for testing advice.
« Reply #7 on: March 01, 2021, 11:40:32 am »
Hi @Serge125 and all,

I'm a huge fan of my HP/Agilent 6632Bs. They're a bit large and heavy and don't have binding posts in the front panel, which makes them super-cheap to get for the performance and features they bring. It's fairly easy to mod binding posts onto them (Dave has a video, I went another way and 3D printed a little panel sitting between two stacked 6632Bs which has also ground and remote sensing posts), and since they have a turning knob they do work well as bench PSUs despite being system PSUs.

They're quite low noise (0.3mV/2mA rms) 2-Quadrant 20V/5A supplies with surprisingly high resolution & accuracy voltage and current read-back (0.03%+3mV, 0.1%+2.5uA up to +-20mA, 0.2%+0.5mA above - I have multimeters that are worse!)
The fact that they're 2-Quadrant is very nice as well, I use them much more often as electronic load than I thought I'd do before I got them. (Eg for a quick test how much juice a battery still has in it). They can take their full rated current & voltage as load as well, and not only a reduced load like some 2-quadrant supplies.

The only downside (besides size of course) is that they have a slight delay in CV->CC transition, which can be a problem when you eg power LEDs directly. In this situation I usually short out the supply before enabling the outputs, to make sure it's in CC before the DUT is powered.

I see a bunch of them on eBay.ca right now for about 100$ more than the Korad, at a much higher level of performance and features. They're heavy though, so it's best to wait for one with reasonable shipping.

Hth,
Alex
 

Offline radiolistener

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Re: Bench top PS for testing advice.
« Reply #8 on: March 01, 2021, 12:17:57 pm »
I would like to buy a bench top power supply to be used to fix electronics (just the basic all around home stuff; receivers, computers (old Comodore etc...), lcd/led tvs etc...you know what I mean) and I want to buy it at Amazon. Yeah I could buy a very expensive one but don't have that type of cash I just want one that is flexible at doing what I need BUT not end up to a point that I need something a bit bigger later on, just an all around good ps.

KORAD KA3005D: https://www.amazon.com/KORAD-KA3005D-Precision-Adjustable-Regulated/dp/B0084JFWNY

This is really good workhorse
 

Offline Serge125Topic starter

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Re: Bench top PS for testing advice.
« Reply #9 on: March 01, 2021, 06:07:27 pm »
Howdy Serge125,

Did you buy this PS, if so how do you like it so far?

Yep I did and yeah I like it I was able to FINALY check a problem with a Christmas inflating snoopy the fan motor wasn't turning but just "jerking" so I thought it was the motor that was shot but with my new bench PS I was able to apply the 12v needed and BAM the motor turned as it should so now I know the wall ps is the problem. I know with time I will find limitations to what it can't do compared to the more expensive ones but for now it does for what I need!!
 


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