Kapanadze Cousin - DALLY FREE ENERGY

[Jeg]

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

I will check it again later on cause i am not home, but i think 370uF per cap

I have a bunch of varistors at 220V, thanks for notifying this!!

[Void]

I will check it again later on cause i am not home, but i think 370uF per cap

and the voltage rating on them? Just a double check to get an idea of what
sort of max input voltage you must not exceed into the power supply...

[Hoppy]

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

The NTC acts as a thermal fuse in series with the mains supply. It is designed to take a surge on connection to the mains as the big cap (400v rated after the FWBR) charges up to around 375V. Don't alter the cap size as its designed to suit the current rating of the SMPS.

So long as the input voltage is not higher than the mains and is not spiking badly when scoped, then this should be fine. Most SMPS PSU's have quite a wide input voltage range. The input voltage is very unlikely to rise to the specified max when loaded by the device. C36,37,38 & L13 is the filter.

[Void]

The NTC acts as a thermal fuse in series with the mains supply. It is designed to take a surge on connection to the mains as the big cap (400v rated after the FWBR) charges up to around 375V. Don't alter the cap size as its designed to suit the current rating of the SMPS.

Thanks Hoppy. So it is in series in the neutral line? It adds resistance and reduces current surge
until it warms up, and then has negligible resistance, or how does it work exactly?

Regarding the voltage on the electrolytics, 240Vrms x 1.414 = 340V
Would that not be the voltage on the filter caps?
Either way, I would hope the caps are rated at 450V if the operating voltage is that close,
but maybe they pinch every penny.
All the best...

[Hoppy]

Thanks Hoppy. So it is in series in the neutral line? It adds resistance and reduces current surge
until it warms up, and then has negligible resistance, or how does it work exactly?

Regarding the voltage on the electrolytics, 240Vrms x 1.414 = 340V
Would that not be the voltage on the filter caps?
Either way, I would hope the caps are rated at 450V if the operating voltage is that close,
but maybe they pinch every penny.
All the best...

See:  http://www.digikey.co.uk/Web%20Export/Supplier%20Content/api-technologies-1171/pdf/api-ntc-engineering-notes.pdf?redirected=1

Most are 400V rated. This cap works very hard and must be a 105 degree working device with low ESR.