Adjustable +/- 0-50V 0-5A Power Supply Schematics

[fjromero]

Fuente regulable de 0 a 50 v. - 0 a 5 amp.

[jackinnj]

This will do just fine -- HP6129C 0-50V, 5A Continuous:

[joaquim]

Very very very VERY nice! HP's test equipment has always been my kind of flavour, and B&K...

I'm in the "start blocks", to begin a new project, a dual Lab-PSU. I have spent many hours with Pspice(OrCAD v.16) to come up with a high V/A dual linear power supply, with all the necessary "trimmings".
Like(except the obvious feature, V-adj.), ampere adjustment, over voltage - i.e, if you want to drive an old HAM Radio equipment you don't want to get a spike - Digital volt/ampere display, a AC-millivolt meter to monitor noise, short circuit prof, and more...
I'm going to write a "diary" 'bout this project on my blog, the "heart" of the bench psu, the trafo, came with the post last week. It's ring trafo, 2x42VAC@650VA, it has 10-0-10 and 12V~, as well and is necessary for the project, LAB-PSU.

It's an "all discrete" design, I use a couple of OP-Amps for monitoring, and ICL7107 for voltage and ampere...

It(or I'm aim at...) will be capable to deliver +/- 50VDC, @ 7 - 10A per rail.... 6xMJ15003/15004 parallel coupled, output BJT's, MJ1500x is capable of 250W, 120V, 20A each, so about 1.35A@50V each, comes to approximate 70W, so cooling shouldn't be a problem...

But one might find a used unit, slightly defect on E-bay, that's worth while to repair... but it is more fun, building your own, or?

[jackinnj]

Joaquim:

I think that a simpler design strategy is to use a 500 watt Class-D amplifier and drive a power transformer, rectify and filter -- you can use an analog opto-coupler to provide feedback -- this way you burn many fewer watts with minimal energy dissipated in pass devices. I'd spend the time programming a DAC with a modified sine wave to boost the efficiency but spare the design the switching transients of a DC-DC converter.


Two of the HP supplies were purchased surplus from an aircraft/defense contractor in NY for $1, but I had to pick them up!

[Sch3mat1c]

Cough, or make a real switching supply...

Ugh, class D amp with iron transformer and big filter caps? I'm gonna be sick.

[jackinnj]

Originally Posted by Sch3mat1c

Cough, or make a real switching supply...

Ugh, class D amp with iron transformer and big filter caps? I'm gonna be sick.

Those HP6129's are just amplifiers -- uses a DAC made of discrete components -- each bit is trimmable.

I am just pulling a leaf from the book I worked in decades ago -- we used Mac's with 6L6's to power the ultra-low noise stuff in the lab. No reason it couldn't be implemented with some DSP at a higher switching frequency.

[joaquim]

Well I've paid a smaller fortune for the trafo - 650VA... But I was going to build a SMPS as a LAB PSU at first... I have a 0-250V~ 3A Variac, to which I can hookup any trafo and adjust the output, I have a circuit board with a rectifier B1000C25000 and 100V, 10 000µF cap's on it, and old-school stabilization, two 40W light bulbs
And it's been used to death, or almost anyway... the panel instruments, V/A, has give in, and sure I can use a DMM to monitor the voltage/current...
But I'm a bit "goofy" that way, I want to build everything analogue and with discrete components if possible...
I work with AVR/PIC C programming day out and day in... and it's cheap, easy(if you can C or Assambler), one MCU say ATxmega - Almost any model - can both switch, drive a LCD, "show" noise, draw up graphs and more, and all that for less then €10 + x-hour of programming, but most code you can copy of the net, and modify to fit your purpose. And templates and other pre-done code, comes with AVR Studio SP2. I've used ATmega32 16MHz clock to almost everything, the draw back is that it has no DAC's and UARTs, in all other way it's a great easy to use MCU. I recommend it as a "beginners" circuit. It has JTAGICE(mk I) interface and is fully supported by AVR Studio 4 SP2, for "xmega" you'll need the JTAG ICE mk II, ATMEL's own is recommended, it has all features, Programmer/Debug/IPS etc. Now I'm way of topic.. sorry 'bout that .

It will be a linear all discrete components design! Maybe l8 on I'll get "down and nasty", with an all "digital" SMPS Lab supply... I can always start with programming the MCU, I reckon it'll take many hours behind the keyboard before I get it right... when you think you've got just right there's some bug in it, "to err is human", or ;-)

[wjhos]

Hello,
I am interested in your dual power supply +/-50v
From the schematics and the BOM i gather that there is a site where i can find more info regarding specs, possible mods, calibrating, PCB layout etc. Can you help me out.
regards

W.J. Hos