Advice on cheap Lab Supply 30v 5amps seen all the stuff on ebay best quality?

[pickle9000]

@dssence

- Current limiting is the default setting for this type of supply. Just like it sounds it prevents whatever you hook up from taking more current than you set. If you set it for 1 amp it will only deliver 1 amp no matter what (even if the circuit wants more). The other setting is Over Current Protection, if you set the over current protection for 1 amp the controller will turn off the output if the draw is over 1 amp. Current limiting has many uses, Over Current Protection is protective, preventing damage.
- Overshoot is related to voltage. Lets say you set your voltage to 12 volts, you turn on the output and for a split second the voltage reaches 12.5 volts (a 0.5 volt overshoot) then settles down to 12 volts. Depending on the situation you can damage the device you are powering. Overshoot is not unusual in a supply but is not desirable particularly in a bench supply. 
- That new Korad does not have presets (memory) and does not appear to have USB. Presets are a very handy feature, same for the USB. Other than that it looks the same.

[Electro Fan]

If want a Korad and you can wait until March this could be the new low cost leader at $79.99 (including free shipping - probably in the U.S.):

http://www.ebay.com/itm/KORAD-PRECISION-VARIABLE-ADJ-30V-5A-DC-POWER-SUPPLY-DIGITAL-REGULATED-LAB-GRADE-/131013279686?pt=LH_DefaultDomain_0&hash=item1e80ffffc6

"If your product is damaged in shipping or is found to be defective in any way during the 1st 30 days after receiving the item, we will pay to have the defective/damaged product returned to us and issue you a 100% refund or we will repair or replace the unit at no charge.

If the buyer is returning the product due to "Buyer's Remorse", then the buyer is responsible for the return shipping. The product must be returned "NEW & UNUSED" as it was received in the original box with all parts/paperwork.

You will need to contact us for a Return Authorization Number before you return it for any of the reasons above."

Hi is this better than the other 2 korads? or there are functions missing.

This is not better, just less expensive.  If you can afford the KA3005P, that would be the way to go; next is the KA3005D, then the $79 model.  Kind of depends on your needs and budget.

[dssence]

HI so I came across this guy from poland , and I didn't like what he said about the korad he got. Makes me really think it twice.
  Any advice? on some other brand .

structLeniwiec
7:00 AM
 
From the very beginning, just after I got my ka3005d, I had plenty of problems with them. The first unit had to go back to the supplier about a week after I received it, because unexpectedly I got around 14VDC on output, no matter how I would set the voltage and current. My main scope of interest are digital circuits and most of the time I use 3V3 and 5V powered circuit, so you can imagine how much damage this issue could have done if I hadn’t been careful enough. In the second unit there was no isolation, no heat-shrink on soldering points, on 230V AC power rails, which go from the back panel main socket to front panel mounted on/off switch. And the space between those joints and the metal chassis was about 2 or 3 mm (not more, in any case). The soldering joint of the main wires was of such a poor quality that it broke after few months of normal use and I got full 230VAC on the chassis! Luckily, the main panel is made from PVC and it didn’t hurt me, but it is totally not acceptable in any gears, even those “el cheapo”.

Maybe it is only my bad luck with these power supplies, and only my units were broken, but set aside safety and quality, I think korad ka3005d is simply badly designed. Let’s say that we ignore those esoteric DACs, which were built on shift registers and R2R leaders, on some other fancy-Chinese-solutions, but I can assure you that the Chinese that designed those units have absolutely no idea of what the thermal resistance is and how to handle it in design.

One more thing, this power supply never ever gives you full 5A of current in the whole 0 to 30V range! And it never gives you continuous 5A of current – after a few minutes, the thermal protection starts to work and the power supply shuts down until it cools down.

I also wrote a post on my blog about some modification which I done: http://www.leniwiec.org/en/2014/01/06/korad-ka3005d-silent-fan-hack/?

[rdl]

HI so I came across this guy from poland , and I didn't like what he said about the korad he got.

If you look at his photos you can see the power board and it looks like the early version, before they fixed the problems with the output transistors (in EEVBlog #404 you can see the old and new boards side by side).

[pickle9000]

@dssence

My advice is that if you don't have confidence in the Korad don't buy it. "Confidence" is an important word in electronics, if you can't trust your equipment everything will take longer.

Look at the Rigol 832 that Dave just purchased. He has confidence in Rigol, the supply had some features he wanted and a good price. What happened? It had a design fault (a couple at least). Rigol fixed the issues and repaired the faults. Rigol did good, they may have not fixed the problems to everyone's liking but they did fix them. Korad and the sellers of Korad products could learn a lesson, stating that it is a revision 2 unit or whatever and stating that upgrades have been done. The problem with that of course if that you could have 20,000 customers knocking on you door saying fix the old one.

As for me I went and ordered another Hantek unit. The price was just too good to resist. My confidence in the unit is good enough to do that. I will end up changing the electrolytics in it but don't take that as meaning it's crap. I have done this for many years. Electrolytic capacitors are the most common thing to fail in any equipment and I like to have nice ones in place. I still don't know the OEM for this supply but it certainly has been built down to a price. If you do go for the Hantek, I purchased from techrecommends in Canada. I'm in Canada so for me that was part of the decision. I don't know who the guy is but I think it is either a Hantek dealer or Hantek itself. Most of the other stuff being sold seems a little overpriced for an ebay seller. 


 

[dssence]

@dssence

My advice is that if you don't have confidence in the Korad don't buy it. "Confidence" is an important word in electronics, if you can't trust your equipment everything will take longer.

Look at the Rigol 832 that Dave just purchased. He has confidence in Rigol, the supply had some features he wanted and a good price. What happened? It had a design fault (a couple at least). Rigol fixed the issues and repaired the faults. Rigol did good, they may have not fixed the problems to everyone's liking but they did fix them. Korad and the sellers of Korad products could learn a lesson, stating that it is a revision 2 unit or whatever and stating that upgrades have been done. The problem with that of course if that you could have 20,000 customers knocking on you door saying fix the old one.

As for me I went and ordered another Hantek unit. The price was just too good to resist. My confidence in the unit is good enough to do that. I will end up changing the electrolytics in it but don't take that as meaning it's crap. I have done this for many years. Electrolytic capacitors are the most common thing to fail in any equipment and I like to have nice ones in place. I still don't know the OEM for this supply but it certainly has been built down to a price. If you do go for the Hantek, I purchased from techrecommends in Canada. I'm in Canada so for me that was part of the decision. I don't know who the guy is but I think it is either a Hantek dealer or Hantek itself. Most of the other stuff being sold seems a little overpriced for an ebay seller.

Hi thanks so much I've finall decided to guy with mastech either of these which one would be best? Maybe the 10 amps is better built. Now will these units if I say.  Set the amps to 4.5 amps and voltage to 5volts and my device starts drawing more than 4.5amps. Will the supply overprotect I do hope it does have shortcircuit protection both can you help me out

http://www.ebay.com/itm/MASTECH-HY3010E-30V-10A-Lab-Grade-Regulated-Variable-Linear-DC-Power-Supply-/221291395770?pt=LH_DefaultDomain_0&hash=item3385febaba

http://www.ebay.com/itm/Mastech-HY3005D-Lab-Tattoo-Linear-Variable-DC-Regulated-Power-Supply-30V-5A-110V-/140985160837?pt=LH_DefaultDomain_0&hash=item20d35ed485

[pickle9000]

I think you have enough info to figure out the rest, read the manuals (use pfd in the search). Search the forum here is the one from your last post https://www.eevblog.com/forum/testgear/mastech-hy3010e-3-power-supply-noise/.

Any time you see a supply with more than 3 amps make sure you check the manual to ensure it is not a switching type. The hy3010e appears to be a switching one and is probably labelled incorrectly on ebay. As for the other one any time you see "power supply" and "tattoo" in the same line going elsewhere is probably best. That has nothing to do with the supply just a bit of common sense.

I can't give any advise on Mastech stuff I don't own any. I'm sure you can find some reviews.

Remember supplies are normally purchased according to the job they need to do. When you can't find one to do the job you build it. In my experience having 3-5 bench supplies is perfectly normal, more in many cases. That does not include the box in the closet with specialized fixed ones.

[dssence]

I think you have enough info to figure out the rest, read the manuals (use pfd in the search). Search the forum here is the one from your last post https://www.eevblog.com/forum/testgear/mastech-hy3010e-3-power-supply-noise/.

Any time you see a supply with more than 3 amps make sure you check the manual to ensure it is not a switching type. The hy3010e appears to be a switching one and is probably labelled incorrectly on ebay. As for the other one any time you see "power supply" and "tattoo" in the same line going elsewhere is probably best. That has nothing to do with the supply just a bit of common sense.

I can't give any advise on Mastech stuff I don't own any. I'm sure you can find some reviews.

Remember supplies are normally purchased according to the job they need to do. When you can't find one to do the job you build it. In my experience having 3-5 bench supplies is perfectly normal, more in many cases. That does not include the box in the closet with specialized fixed ones.

Damn this is almost impossible, near all the linear supplies have one or another problem . I thought this mastech was a good one and now it results it does have more noise than the acceptable levels on spec.
    What about this one instead

http://www.ebay.com/itm/Mastech-HY3005D-Lab-Tattoo-Linear-Variable-DC-Regulated-Power-Supply-30V-5A-110V-/140985160837?pt=LH_DefaultDomain_0&hash=item20d35ed485

I'm honestly tired there's like nothing without it's cons

[Pasky]

I think in a couple weeks I'm going to grab the Korad, after watching Dave's reviews, it seems like a nice unit for the price other than the transistor problems, which seems to have been resolved.

[GiskardReventlov]

I don't know a lot about BK products (I own a BK DMM) I think the company's been around for a long time. I do recall seeing a BK power supply on Dave's bench.

36V and 3A and $107 with a trade-in of anything (I don't think they care what you trade-in I've entered Micronta 22)
https://www.bkprecision.com/products/power-supplies/1550-switching-dc-bench-power-supply-with-usb-charger-output-1-36v-0-3a.html

Triple output,One variable 0 to 30 VDC, 0 to 5 A variable section, One 12 VDC fixed section, One 5 VDC fixed section
$157.68
https://www.bkprecision.com/products/power-supplies/1671A-triple-output-30v-5a-digital-display-dc-power-supply.html

This one's interesting
Digitally controlled, mixed mode linear/switching DC power supply for $208
https://www.bkprecision.com/products/power-supplies/9110-100w-multi-range-60v-5a-dc-power-supply.html

All those prices I found by going to this page:
https://bkprecision.com/promotions/exchange-program.html

The exchange doesn't seem to matter, you can enter in a $3 pocket DMM and they give the same discount. I have not tried it yet but may be getting one of the above. Possibly the 9110 unless I find a horror story about it.

[nanofrog]

Go with a used unit. You can get a lot more PSU for the money (linear, better specs, built like a tank, dual or even triple output) for similar money as you've been looking to spend. Worst case, you'll need to be a little patient for the right unit at the right cost to be posted.

Example.

[London Lad]

^^^ agreed. most of these cheap new units are of poor build quality.

As I said before a good used farnell supply is a far better bet. Farnell the manufacturer not Farnell the retailer that is.

[dssence]

Guys do you know if this hantek supply is switched supply or linear regulated ?

HANTEK PPS2116A

http://www.hantek.com/en/ProductDetail_33.html

[Fsck]

Guys do you know if this hantek supply is switched supply or linear regulated ?

HANTEK PPS2116A

http://www.hantek.com/en/ProductDetail_33.html

looks linear to me.

[Electro Fan]

looks like a whole family of Power Supplies:
http://www.hantek.com/en/ProductList_1_10.html

[HiTech]

I didn't read every reply due to the 5 pages of tedious reading but my serious advice is to forget the Asian crap out there and buy used HP, Power Design, Sorensen, or Trigon. These are high quality linear supplies built like brick $hit houses, capable of withstanding daily stresses. I just sold a working HP 0-40v 5amp supply on another electronics forum for under $50. EBay has many of them up for sale... my preferred favorites being either HP or Power Design brands. They often sell for well under $100 and more typically around $50. Adjustable voltage, adj. current, short-proof, meters to monitor both voltage and current and much more. Avoid the weaklings like Mastech, Instek, B&K, Tenma, etc. Even the VIZ line is better than the weakling brands I just mentioned.

[robrenz]

I didn't read every reply due to the 5 pages of tedious reading but my serious advice is to forget the Asian crap out there and buy used HP, Power Design, Sorensen, or Trigon. These are high quality linear supplies built like brick $hit houses, capable of withstanding daily stresses. I just sold a working HP 0-40v 5amp supply on another electronics forum for under $50. EBay has many of them up for sale... my preferred favorites being either HP or Power Design brands. They often sell for well under $100 and more typically around $50. Adjustable voltage, adj. current, short-proof, meters to monitor both voltage and current and much more. Avoid the weaklings like Mastech, Instek, B&K, Tenma, etc. Even the VIZ line is better than the weakling brands I just mentioned.

+1  excellent advice

[GiskardReventlov]

Hadn't heard of Trigon before, there's also a Thandar brand I see on ebay but don't know about it. I like the look of the power design with the aluminum knobs. Advantest was reviewed recently too, but high end. All the asian stuff is getting scarier all the time.  The rigol dp832 and then there's the Youyue 858D+ thread here and then I've heard mention of other manufacturers cloning the asian stuff.  We all know what happens when you copy an already bad copy.

[pomonabill221]

There is also Lambda power supplies.

[jadew]

Personally, I like the Korad. Seems simple enough to work / fix / mod and is programmable.

Only issue I've been having is that I can't find it in the EU, not with out paying twice what it's worth.

Edit: I like the front panel as well, although I would have preferred it if it had two pushable knobs for voltage and current, instead of those 3 buttons + knob.

[nanofrog]

Hadn't heard of Trigon before, there's also a Thandar brand I see on ebay but don't know about it. I like the look of the power design with the aluminum knobs. Advantest was reviewed recently too, but high end. All the asian stuff is getting scarier all the time.  The rigol dp832 and then there's the Youyue 858D+ thread here and then I've heard mention of other manufacturers cloning the asian stuff.  We all know what happens when you copy an already bad copy.

Never heard of Trigon, but Thurlby Thandar Instruments (Aim-TTi) I have. They've been around for a good while from what I understand, and have made some excellent gear.

[jadew]

I've heard of TTi as well, haven't heard of Sorensen tho.

Now the question is which is which? Because they're both expensive:

[edavid]

Never heard of Trigon, but Thurlby Thandar Instruments (Aim-TTi) I have. They've been around for a good while from what I understand, and have made some excellent gear.

Trygon [note spelling] was a company that was bought by Systron-Donner, so you see their stuff labeled with various combinations of those.  I don't think their power supplies were anything special though.

Thurlby may have made some good equipment, but Thandar, not really.  The TTi power supplies do seem nice, but they are overpriced in the US.

[nanofrog]

Trygon [note spelling] was a company that was bought by Systron-Donner, so you see their stuff labeled with various combinations of those.  I don't think their power supplies were anything special though.

Thurlby may have made some good equipment, but Thandar, not really.  The TTi power supplies do seem nice, but they are overpriced in the US.

Thanks.

All the mergers & acquisitions and/or rebranding products from an ODM is enough to make my head spin most of the time.    

[staxquad]

I've heard of TTi as well, haven't heard of Sorensen tho.

Now the question is which is which? Because they're both expensive:

Ametek, Elgar, Sorensen, XANTREX, all same company, some models have 3 different names on it

have seen many under $100 on Ebay

Dave reviewed a high voltage Xantrex, exuded quality throughout