Bench power supply?
05-27-2020, 07:03 PM
Post: #1
 David Hayden Senior Member Posts: 387 Joined: Dec 2013
Bench power supply?
A couple calculator repair/upgrade projects have made it clearer that I could really use a bench power supply. Does anyone have any recommendations? At a minimum I'd like something that can power calculators, so maybe 0-5V at 1A-2A. It would be nice if I could also use it to check laptops, so maybe up to 20V AC and DC and ... 10A? What does a laptop take?

Thanks for any insights anyone might have,

Dave
05-27-2020, 07:17 PM
Post: #2
 Dave Frederickson Senior Member Posts: 2,118 Joined: Dec 2013
RE: Bench power supply?
Member David Jones has some reviews of power supplies on his YouTube channel. Here's one.
05-27-2020, 07:36 PM
Post: #3
 John Keith Senior Member Posts: 750 Joined: Dec 2013
RE: Bench power supply?
For decent quality and reasonable price, I like Instek power supplies. Many different models available from many suppliers.

As to your specs, I would not recommend using a 10A power supply for working on calculators and similar small electronics. Supplies with smaller voltage and current ranges have finer adjustability, especially among reasonably priced models.
05-27-2020, 07:58 PM
Post: #4
 Maximilian Hohmann Senior Member Posts: 960 Joined: Dec 2013
RE: Bench power supply?
Hello!

(05-27-2020 07:03 PM)David Hayden Wrote:  ... repair/upgrade projects ...

If you can repair calculators, then you can easily repair power supplies :-) I bought one like these (Iso-Tech ips2303) - first google result: https://www.abex.co.uk/esales/test/iso-t.../index.php as "defective" from eBay for less than 20 Euros including shipping. All that was broken was a diode for 20 Cents. Took less then half an hour to find the fault and fix it. The original price must have been something like 200 Euros and even at that price the unit is not expensive.

I like that power supply very much. It is not a switching type but instead uses heavy tranformers with several taps and linear voltage/current regulators. When you increase the voltage you can hear the clicking of variuos relays that select the approriate transformer windings. The two channels can either be used separately or in parallel or series, thereby giving you up to 60V or 6A. Plenty for my need. Additionally there is a completely separate 5V supply which is, as I must confess, the one I use most often.

Regards
Max
05-27-2020, 10:35 PM
Post: #5
 Dave Frederickson Senior Member Posts: 2,118 Joined: Dec 2013
RE: Bench power supply?
(05-27-2020 07:58 PM)Maximilian Hohmann Wrote:  I bought one like these (Iso-Tech ips2303)

Looks a lot like the GW Instek GPC-Series.

05-27-2020, 11:01 PM
Post: #6
 cruff Member Posts: 223 Joined: Dec 2013
RE: Bench power supply?
If you are looking to substitute for a battery, you should probably look for a power supply that has reasonable filtering and low ripple. I have an old ProTek 3015B dual supply that looks horrendous when attached to a load and oscilloscope, but it delivers 0-30V at 1.5 A.

I recently bought a Keysight E36313A triple supply that delivers 1x 5 V 10A and 2x 25 V 2 A that is much cleaner.

Since laptops typically take one supply voltage, you might get by with two supplies, and can use a cheaper one for the higher amperage supply but only require a single output.
05-28-2020, 05:03 AM
Post: #7
 Hans-Peter Member Posts: 97 Joined: Dec 2013
RE: Bench power supply?
This is my absolute favourite PS. I have many table PS but since I own this, I use no others.
I have the short case and underneath the 400W Meanwell. So it is very short.

Hans-Peter
05-28-2020, 11:16 AM
Post: #8
 Maximilian Hohmann Senior Member Posts: 960 Joined: Dec 2013
RE: Bench power supply?
Hello!

(05-27-2020 10:35 PM)Dave Frederickson Wrote:
(05-27-2020 07:58 PM)Maximilian Hohmann Wrote:  I bought one like these (Iso-Tech ips2303)

Looks a lot like the GW Instek GPC-Series.

Yes, that's the one. Also the specifications fit. They either sold it under various brand names or someone made clones from it (like they do with Tektronix oscilloscopes). I would never have thought that the original price is in the 500 Euro range - as written above my estimate was rather 200 Euros. So somethimes it pays off to buy other defective stuff from eBay, not just defective calculators :-)

Regards
Max
05-28-2020, 01:30 PM
Post: #9
 David Hayden Senior Member Posts: 387 Joined: Dec 2013
RE: Bench power supply?
Thanks for the ideas everyone!
05-28-2020, 02:11 PM
Post: #10
 BobVA Senior Member Posts: 381 Joined: Dec 2013
RE: Bench power supply?
HP-6201B - Fourteen pounds of ripple suppression :-)

I'm probably taking things to the extreme with my boat anchor, but you might want to look at older lab gear from the usual suspects (HP, Keithley, Tek, etc). They're great bargains for the performance if you don't need the extra features of the new stuff.
05-28-2020, 02:19 PM
Post: #11
 John Keith Senior Member Posts: 750 Joined: Dec 2013
RE: Bench power supply?
(05-28-2020 02:11 PM)BobVA Wrote:  HP-6201B - Fourteen pounds of ripple suppression :-)

I'm probably taking things to the extreme with my boat anchor, but you might want to look at older lab gear from the usual suspects (HP, Keithley, Tek, etc). They're great bargains for the performance if you don't need the extra features of the new stuff.

Kikusui is another maker of very good linear (boat anchor) supplies.
06-01-2020, 08:27 PM
Post: #12
 GVHOVE Junior Member Posts: 18 Joined: Dec 2018
RE: Bench power supply?
I've been using a 0-20V HP6632A 100W DC Power Supply for some time now.

Control it with my HP-41 via the HP82169A HP-IL/HI-IB interface.

Picked it up on TAS for $70, but has done the job for a number of years now. If possible go for the one with option 020 (front panel connectors). BTW : see also HP6633 (0-50V) and HP6634 (0-100V) 06-01-2020, 08:40 PM Post: #13  John Keith Senior Member Posts: 750 Joined: Dec 2013 RE: Bench power supply? (06-01-2020 08:27 PM)GVHOVE Wrote: I've been using a 0-20V HP6632A 100W DC Power Supply for some time now. Control it with my HP-41 via the HP82169A HP-IL/HI-IB interface. Picked it up on TAS for$70, but has done the job for a number of years now.
If possible go for the one with option 020 (front panel connectors).

Can't think of anything better for working on HP calculators!
06-01-2020, 09:23 PM
Post: #14
 GVHOVE Junior Member Posts: 18 Joined: Dec 2018
RE: Bench power supply?
Just for reference : the recommended retail price for an HP6632A power supply when it came on the market was $1600 (see attachment) So for$70 I have the pleasure to work with top-equipment ... from the late 1980's.
From a time when HP equipment was designed/made to last forever !

For those interested : I have the Operations Manual and Service Manual available in pdf

Attached File(s)