High current supply for testing

[bnae38]

Found a spool of heater element, actually had it forever.. it just dawned on me what it is.

Current sharing seems a bit closer than I thought at ~109A.

17.2mv drop on supply one 8 awg wire.
20.1mv supply 2
18.9mv supply 3

 

[bnae38]

Hit 170A (briefly of course) on a power sweeps at 1.3R on this guy. Supply running like a champ.

 

[matcza]

Hi, I have a problem with OVP, im done every change like on your photo, the PSU turn on with >14V, working about 30s and kicks off. Have you any advice to fix it?

 

[bnae38]

In photo 3, did you add 22k to existing resistor? Need to add 22k on top of existing resistor. Probably should have made that clearer.

 

[matcza]

Yes, i did it

 

[bnae38]

Hmm.. rev 2f units, same as mine?

Not sure, the one I blew up f'ing around. But the other three I modded all performed the same.

 

[matcza]

I have the same unit, but the difference,
I used 24,9k instead of 24k, and like at the photo i add the 22k. I didn't changed the rezistors next to pot like you at first photos.

 

[ultra]

Here is a test i did around 10 years ago to a modified amp.

 

[bnae38]

I have the same unit, but the difference,
I used 24,9k instead of 24k, and like at the photo i add the 22k. I didn't changed the rezistors next to pot like you at first photos. View attachment 1195070

Ok, my post 12 had the final tweaks I did to get there. Don't worry about the photos prior to that.

If you have done that, then your rev may have a slightly different circuit in one or more places.

 

[Perry Babin]

Did you ever produce a diagram for the control circuit? A diagram with the voltages would help troubleshoot for those trying this mod.

 

[matcza]

It wasn't a OVP problem, it was a overheating problem. This part heats up to 50.5 celcius on the top and the PSU shuts down.
I added an external fan and the PSU works. But why? What is this part? why it's heating a lot?

 

[matcza]

Sorry, it's not this part. Its one of parts on daghter board. I hacked another, the same PSU, and everything is ok, 14,5V. You had similar problem, have You any idea to fix it?

 

[bnae38]

Not sure I understand. What problem?

 

[matcza]

Sory, you right, clearly.
When your ucc37323 overheated, did the power supply turn off from overheating or work normally?

 

[bnae38]

I only noticed excess heat from the chip, it never caused me any problems.

 

[matcza]

ok, thank you

 

[pan_sattan]

Hi, is still this topic alive? I tried to modify this PSU HSTNS-PD19 Rev 04F and its dead... no voltage goes out.
Is there somebody who has schematic or can guide me which component to change on driving board?

used resistors 22K*2 and in shrink 12K

 

[pan_sattan]

 

[bnae38]

Did it turn on prior to modifications?

 

[pan_sattan]

yes, it runs - 12V out