Kapanadze Cousin - DALLY FREE ENERGY

Hoppy · April 21, 2018, 11:07:09 AM

Quote from: NickZ on April 21, 2018, 09:54:00 AM
Hoppy:
The NTC is ok.
Just trying to find a fuse to replace the small T5A brown one that burnt out.
I'll know more later today. What tripped me up, was that there was still some voltage at the caps, and at the mosfet, even with a partially blown fuse. That's why I thought that the fuse was ok, but it wasn't.
I wish that the T5A had blown before it messed up the caps, and who knows what else.
But, I saw a spark under that fuse, (it totally blew afterwards). But, that happened after I had replaced the caps, and not before the damage. That fuse was too slow, (it's a slow T-type of fuse).
Probably needs an quicker F fuse, instead.

Sorry apecore for the off topic discussions. But, you'll probably see that once you connect up a feed back circuit, that fixing a burnt PS, won't be off topic at all. Dally went through a couple of burnt up PS, before finding one that worked.
I think that a 110v- 220v PS is what's needed. And NOT the 110v PS, like the one I'm using now. Live and learn...

Nick,

The T-type fuse is there for a good reason. A correct rated quick blow fuse will likely rupture on the current surge when the big caps initially charge-up from empty. Replace it with the proper type and rated fuse. As I mentioned earlier, you can progress the repair by temporarily using a thin bit of fuse wire, or a thin strand from a stranded hookup type wire or similar but make sure the bulb is in circuit.

NickZ · April 23, 2018, 12:10:29 PM

Quote from: Hoppy on April 21, 2018, 11:07:09 AM
Nick,

The T-type fuse is there for a good reason. A correct rated quick blow fuse will likely rupture on the current surge when the big caps initially charge-up from empty. Replace it with the proper type and rated fuse. As I mentioned earlier, you can progress the repair by temporarily using a thin bit of fuse wire, or a thin strand from a stranded hookup type wire or similar but make sure the bulb is in circuit.

Hoppy:
I've now replaced the brown fuse for one out of my older PS, which is a T3, for now.
But, it seams like there is no return path through to the ground side. Any ideas...

EDIT: ok, I just found that it's the bulb socket that won't allow a 50w bulb to screw in all the way. I could get a 25w bulb to light in that socket though. So, I'll see if now I can get the 120v through the 25w bulb to the PS, and see IF the PS works now.

So, here's a little video for Hoppy, AG, and all.
https://youtu.be/Ojomw4e0FWA

Hoppy · April 24, 2018, 03:01:52 AM

Thanks for the video Nick. Looks good to go but check that the 12V / 24V switchable output voltages are correct.

NickZ · April 24, 2018, 09:13:09 AM

Hoppy:
Yes, everything works. I have 24.2v output, again. I also connected this fixed PS to run my device, and all is good to go.
Now it's back to where I was at when that happened.
I have a feeling that this kind of thing may happen again, so it's good to know how to deal with it in the future.
It was worth the effort to learn just how to fix these PS.
Thanks again for your help.
NickZ

Hoppy · April 24, 2018, 02:44:16 PM

Nick,

Its likely that the damage to your PSU was caused by disconnecting the output bulbs, resulting in a sudden increase in voltage input to the feedback PSU. Make sure you have a permanently connected load at all times when testing. The bulb wattage for the permanent load should be chosen to ensure that the voltage across it always stays within the rated input of the feedback PSU. The main supply battery will only present a load to the feedback PSU when its terminal voltage falls below the PSU output voltage.