Feeding a SMPS with DC instead of mains

[jmaf]

There are some things to think about when feeding DC. Don't forget a fuse, a common mode filter and some filter caps. The filter caps are partially to give a low impedance source at the switch and also to prevent EMI. Another consideration is the 220VAC will rectify to give about 330V DC. In other words 220V DC isn't enough and that can cause major problem if the switcher has not been designed to operate at that voltage.

Another consideration is that some SMPS's (mainly lower voltage input ~120VAC types AFAIK) use a voltage doubler and that requires an AC input.

All great points indeed. Thank you.

[nickb]

There are some things to think about when feeding DC. Don't forget a fuse, a common mode filter and some filter caps. The filter caps are partially to give a low impedance source at the switch and also to prevent EMI. Another consideration is the 220VAC will rectify to give about 300V DC. In other words 220V DC isn't enough and that can cause major problem if the switcher has not been designed to operate at that voltage.

Another consideration is that some SMPS's (mainly lower voltage input ~120VAC types AFAIK) use a voltage doubler and that requires an AC input.

[jmaf]

(I guess this qualifies as circuit bending? I came to post this under the lounge or offtopic stuff. Please move if wrong? Thanks!)

A friend of mine built a 220 V DC battery. He's experimenting with some solar power stuff. (I've warned him about safety and 220 VDC with no circuit breaker at the terminals, he says he'll be careful.)

So i had the idea that a SPMS' first thing is always a rectifier (right?), so....the 220V mains fed into it is immediately rectified before being oscillated?

Is there any problem with feeding a switch mode PS with 220 VDC directly instead of 220 VAC RMS mains? Will it damage anything if used continuously with DC instead of mains?