Need a Bench variable power supply?

[ronyd]

Looking to purchase new or used variable 0-30vdc power supply for my electronic drumming projects.

Seems like any sold Amazon (mostly chinese makers) < $140 or so all have the same issues with fine voltage and current adjustments, and/or just not reliable after months of use.  And the reviews vary for the same supply.  Who says it's great and other not so. Just don't trust the reviews.

Is there any supplies out there < $100 that are reliable and have good control over adjustments to voltage and current?

Or do i just have to bite the bullet and spend $300+.

[Grandchuck]

Older, used supplies are usually more repairable.  If you have the skills and the wherewithal, a used unit could be your best option.

If so, try to find one that was made by a notable company and one that information is available for.

[ronyd]

yeah i hear ya.

I bought a Tektronic oscope used in perfect condition for $200 with a function generator.

[MikeK]

Lots of satisfied users of the Korad supply.  They had issues early on, but it has gone through several revisions.  It's linear, not switch-mode, and hard to beat for the price.

[mag_therm]

Hewlett Packard made a range of similar, linear power supplies from 1960's to 1980's.
I have two of HP 6253A each rated 2 * 24 V 3 A from BMI Surplus. Some resto was needed when I got them about 12 years ago.

They are old, large, heavy, inefficient, but reliable in my experience. I & V reg both go down to zero. and with coarse/fine trim pots.
And the dual supplies work well either in series or parallel.

[radiolistener]

KORAD KA3005D, it provides up to 31 V / 5.1 Amp

[MikeK]

You should be able to get this very cheap:

https://www.ebay.com/itm/254871206331

Yes, his asking price is overblown, and I've already told him so.  He now knows that a similar new one is about $90 on Amazon.  If you point out "Hey, this seems to be the same as the Mastech supply...I could give you $20 for it", you could probably get it.*  I think he's getting a lot of his stuff for free or very cheap and he looks up prices but doesn't really know what things are worth.  If you're interested...Pick a price, let me know, and I'll offer him less so that your offer is more attractive.  I don't need yet another bench supply (unless it's a fancy precision one).  By the way, I've already bought other things from him (two multimeters) so he is legit.

* A better approach might be to first mention that the *NEW* Mastech HY3003D is *MUCH* cheaper.  When he asks if you're interested in it you could say that what you'd be willing to offer is much less.  Then, if he bites on that, offer your lowball.

Mike

[Doctorandus_P]

So if you buy the cheapest stuff you can find you get crapped on, and internet reviews are not reliable.

What else is new.

[MarkF]

I like these little low power Hewlett Packard HP 6216A Variable DC Power Supplies. 
Although this one is over priced.  I usually was able to get them for $50 with shipping included.

[austfox]

You could always build your own. Silicon Chip has just published a 30V 2A design in their current issue:

https://www.siliconchip.com.au/Issue/2022/October/30V+2A+Bench+Supply%2C+Part+1

[Gyro]

That one looks like an LM317 with external current boost transistor. Maybe not an ideal starting point (but should work if the current limit can be made reliable).

[Excavatoree]

I have one of these, and it's a good supply, if you only need 1.5 amperes.  The pots are 10 turns, and it performs well.  I'll admit that I paid 40 dollars (edit: each) for two or three of these at my surplus dealer, years ago, and thought it was a good deal. 

https://www.ebay.com/itm/361975454012?hash=item54476b193c:g:QtEAAOSwZKBZEimW&amdata=enc%3AAQAHAAAAoM769xSakKFhlE4HkvVoqal4qqXAjrEzOy9KYqSaYB%2FzSQx3sdD3%2Bx4oqkqSQ60BiQ3rh1RxM5DMzZaELwowaZb5Uwoh3gmz121YYI31NJ5L408HQEZUlB%2FTnWBlZTpvryga8xEAptAxW687PXlDoW7iQiq2Ec%2BHvR7zpVy%2Foc%2BwKWYQb6EcDahPf3LhYzQnoNAA391KnlnMCoy0mapXSDU%3D%7Ctkp%3ABk9SR6z17cv2YA

[brucehoult]

Dumb question, and I'm looking at buying my first adjustable voltage and current power supply myself ... but why do you (or I) need 30 V?

Virtually everything I do is 3.3 or 5 V. I can see needing 12 V occasionally.  But 30 ??

I've been using Apple / Samsung / RPi 4 USB 5V power supplies which generally can give all the current I need, but not enough to let out magic smoke. The Samsung and Pi 4 ones are 15W/3A, Apple is 18W or 20W. They're all pretty cheap if I blow up a power supply :-)  And decent quality as far as I can tell.

But I'm thinking about dropping some money on a bench supply that can limit the current to less, and not itself get blown up.

I'm tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

[MarkF]

I'm tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

If you're going to drop that kind of money, consider the Siglent SPD1305X (30V/5A) or the SPD1168X (16V/8A).

   

[ledtester]

tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

fwiw, it looks like it is also sold as a "Tekpower TP3005T":

https://www.amazon.com/Tekpower-TP3005T-Variable-Linear-Alligator/dp/B00ZBCLJSY/

[brucehoult]

I'm tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

If you're going to drop that kind of money, consider the Siglent SPD1305X (30V/5A) or the SPD1168X (16V/8A).

   

US$265 plus tax plus shipping from overseas?

The Jaycar I pointed to is US$125 plus tax, available off the shelf in my provincial New Zealand city.

[brucehoult]

tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

fwiw, it looks like it is also sold as a "Tekpower TP3005T":

https://www.amazon.com/Tekpower-TP3005T-Variable-Linear-Alligator/dp/B00ZBCLJSY/

Yup. Looks the same. Looks cheaper at US$80, but Amazon says shipping is $53.22, making it just as expensive as I can get it off the shelf in a retail store in my provincial NZ city. Plus that would come with a US plug and from the specs 110 V only power needs not 240 V.

[bdunham7]

Is there any supplies out there < $100 that are reliable and have good control over adjustments to voltage and current?

How much current do you need?  Older linear supplies from BK Precision, HP, Tektronix, Power Designs and so on work pretty well and are repairable.  Many of them are reverse polarity and backfeed protected so they won't blow up as easily as many modern versions.  A dual-channel 20 or 24V supply can be used in a series configuration if you need the full 30V (or more). 

[Doctorandus_P]

I quite agree with Bruceholt and others here.

30V3A has been a "standard" for 30+ years but electronics has changed a lot in that time span.
I'd much rather have a few small but relative accurate and noise free power supplies than a 30V 3A one.

The smaller power supplies such as 15V 1A can get 90% of the jobs done, and for the other 10% the 30V 3A often is also under powered.
But of course this also depends a lot on the sort of projects you are interested in.

Quite a shame the L200 has gotten out of fashion. It is (was) a 5-legged LM317 with some extra circuitry for current limiting. And by amplifying the voltage over the shunt resistor, it was very easy to make an adjustable current limit with it.

[Peacefool]

You have a nice Tek oscilloscope...  I'd get a good old HP36xx lab power supply to go with it.  Most are CV/CC linear power supplies, w/10 turn pots that blow away the load/line regulation and ripple & noise characteristics of any modern SMPS crap out there, and they're silent too (i.e. no fan) --see attached specs.  I have two HP3616A and they've been solid like a rock.  For modest current requirements you may want to check out this one now:  www.ebay.com/itm/255751227479 (I have no connection to the seller)

[MarkF]

I'm tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

If you're going to drop that kind of money, consider the Siglent SPD1305X (30V/5A) or the SPD1168X (16V/8A).
   . . .

US$265 plus tax plus shipping from overseas?

The Jaycar I pointed to is US$125 plus tax, available off the shelf in my provincial New Zealand city.

The Jaycar link you pointed to lists it for $259.  That's all the further I looked.
Nowhere did you say you could get it for 1/2 price!

[brucehoult]

I'm tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

If you're going to drop that kind of money, consider the Siglent SPD1305X (30V/5A) or the SPD1168X (16V/8A).

   youtube.com/watch?v=ijt5dJLkdRw

US$265 plus tax plus shipping from overseas?

The Jaycar I pointed to is US$125 plus tax, available off the shelf in my provincial New Zealand city.

The Jaycar link you pointed to lists it for $259.  That's all the further I looked.
Nowhere did you say you could get it for 1/2 price!

jaycar.co.NZ

NZD is worth 0.56 USD at the moment. Also NZ advertised prices include 15% sales tax while US one's don't. Also, it's in a retail store local to me, so no freight or import duties etc.

[MarkF]

I'm tending towards this Jaycar labelled one at the moment. Dave didn't hate one of its ancestors a few years ago:

https://www.jaycar.co.nz/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840

If you're going to drop that kind of money, consider the Siglent SPD1305X (30V/5A) or the SPD1168X (16V/8A).

   youtube.com/watch?v=ijt5dJLkdRw

US$265 plus tax plus shipping from overseas?

The Jaycar I pointed to is US$125 plus tax, available off the shelf in my provincial New Zealand city.

The Jaycar link you pointed to lists it for $259.  That's all the further I looked.
Nowhere did you say you could get it for 1/2 price!

jaycar.co.NZ

NZD is worth 0.56 USD at the moment. Also NZ advertised prices include 15% sales tax while US one's don't. Also, it's in a retail store local to me, so no freight or import duties etc.

ARE YOU REALLY GOING TO ARGUE THIS!!!

YES!  JAYCAR.CO.NZ

[brucehoult]

Very good. You can screenshot.

NZ web sites have prices in NZD, and include 15% tax. NZ$259 incl tax is NZ$225 pre-tax which is US$126.42 at this second.

[rdl]

I have a couple of the E3610 power supplies and a couple of these:



The CPS250 (in various color schemes) and the very similar BK Precision 1651 show up frequently on eBay for around $100 and are pretty much all a beginner needs. User manual and service manual are available.

If you go for an HP 36xx try for a later model (three colors binding posts) or Agilent branding as any little problems will have been fixed.