Kapanadze Cousin - DALLY FREE ENERGY

[NickZ]

  Magpwr:
  Yes, that meter seams like it's a very good deal.
  Thanks.

[Void]

What do you say about that? As you see changing diodes is an easy task. I just wonder about what starcruser said  for the filters.

Hi Jeg. I haven't analyzed switch mode power supplies much at all, so assume I could possibly be mistaken
on some of this.

It looks like the section I have enclosed in a white box is where some input filtering components would be, but these
are not installed, so that makes it easy.

As you likely know, the FWBR diodes enclosed in the yellow box should be replaced with fast power diodes if they
are not fast diodes. If you can read the part number on one of their sides, you can check before unsoldering.

What is the part number for the part which I enclosed in the red square? I am not certain what it is.
Can you see any markings on the side of that part?

Overall it looks like you may be able to just put in fast power diodes and you may be set for frequencies such as
27 kHz or in that area. I can't say for certain there won't be other issues as I haven't tried this, but just commenting
on what I think after taking a quick look. There doesn't appear to be much in the way of input filtering that
I noticed, but maybe someone with more experience with switch mode power supplies can add further input...
All the best...

P.S.
What is the voltage rating on the electrolytic filter caps right after the FWBR diodes?
You may well have to add a bit of your own filtering on the AC output of your device if the
signal has any high voltage spikes or whatever on it, before going into the input of the power supply.
You will also want to make sure the voltage of the input waveform is reasonably close to it's rated value.

[starcruiser]

What do you say about that? As you see changing diodes is an easy task. I just wonder about what starcruser said  for the filters.

@jeg,

It looks like this is missing the input surge suppressor(s) caps and inductor already, looks like they were not installed and the inductor is jumpered out. I would check the caps and such following the diodes, draw out the schematic so you can get a picture of what you have and can detemine the operating frequency range. My concern is that the high freq noise might blow the large caps following the diodes due to voltage and spikes. it would be simple enough to replace them with the correct values to avoid the caps from popping. Electrolytics like to do that with AC.

What you might want to do is isolate the front end of the PSU from the rest of the circuit and scope the DC component and see how noisy it looks. you might want to pull the large caps to avoid them from potentially popping while you do this.

Just some ideas.

[Jeg]

Guys thanks a lot for your help.

Void, this component at the input side is an NTC like the one akula uses between ground and the three turns yoke output circuit.
Starcruser, i feel you are absolute right about those electrolytics. They worry me also. I will try to unscrew the pcb so to draw a quick component connection to see what happens. I ll post the result.

[Void]

Guys thanks a lot for your help.

Void, this component at the input side is an NTC like the one akula uses between ground and the three turns yoke output circuit.
Starcruser, i feel you are absolute right about those electrolytics. They worry me also. I will try to unscrew the pcb so to draw a quick component connection to see what happens. I ll post the result.

Jeg, see the edit I added to my comment above. You will likely want to add your own filtering
from the AC output of your device before going into the input of the power supply, to filter out
anything unwanted on the waveform such as any spikes or HF transients or whatever. I wouldn't see a problem
for the filter electrolytics if you do that, as long as they have a suitable voltage rating.  The best thing would be to
wait till you have your circuit putting out a decent AC output waveform (  ) in the right voltage range, then analyze
on a scope and you will see what sort of filtering you might require. That way there is no need to guess...
All the best...


Maybe someone can explain what the NTC (thermistor/varistor?) component is there for? Anyone know? Spike protection?