Power Supply Project Update: Specification/

Atualização do Projeto da Fonte: Especificações

I've been thinking about this power supply thing and came to the following:

• The PS must have only ONE power cord (AC mains) and one "power on" switch;
  
• The connections MUST all be internal to the case, which may be a computer case;
  
• If there is suitable space inside the case (I believe it is) I would like to include some gel-cell batteries;
  
  
  
  • Then, I'll need a good battery charges to be built inside the case, one with good trickle charging or the ability to turn itself off when the batteries are full charged.
    
  • A system to switch from the PS to the batteries in the event of AC mains failure.
    
  • An external DC in jack, to add more capacity if needed.
    

The switching between PS and batteries I plan to accomplish using a DC relay connected to the PS DC out.

I don't have a suitable circuit to do the trickle charging. I would like one tried and working, without exotic components which may be hard to find below the equator...
I don't have either a protection scheme to prevent energy flowing in the wrong direction, simple as it seems I may just put some diodes preventing output to the external batteries and input from the DC output jack and input to the PC power supplies.
The trickle charger may be turned on or off via the same switch that powers the PC PSs, provided that I change it to a 3 position switch (i, 0, ii), being (ii) the trickle charger.

Atualização do Projeto da Fonte: Especificações

Eu escrevi isso tudo antes de ter uma vaga idéia de como funcionava uma fonte de PC. Dê uma olhada nos artigos ao lado.