BL> Yair. These little fuckers are 50% efficient if you're lucky,
BL> and the smaller they get the worse they are. 

DD> National Semiconductor claim 70-80% efficiency....

 ROFL! As the Arab replied whn asked the price of his camels... it
depends on whether you are buying or selling.

 By the time you wire it up, rectify it and filter it, and remove the
interference... 50% is pretty good. At 6V, you are going to lose 1V in
the rectifier, for a start, and there's 85% before you've even
switched your first pulse.

BL> He'll lose 10W+, which is why I suggested an ordinary series
BL> regulator as a viable possibility. He can just wire the whole
BL> thing onto the heatsink and put it in a shoe box with his other
BL> inverter.

DD> Shoe box, other inverter?

 I assumed you already had a 6/240V inverter. As for the shoe box...
you have to be neat, to at least keep the spiders out.

DD> The main SMPS would be left here in the big city where we have
DD> 240V coming out of the socket on the wall. The wall sockets at
DD> my "country estate" only deliver 11.5-14V

 Ahh. I see. It's the other way around! Your VCR runs off 6V and the
inverter is 240/6V. NOW, I understand why you think it won't run off
a 6V battery... you think it may be AC! I'd be surprised if it was.

 An extra 6V battery looks better all the time! Or just tap into
half of your 12 volts. You can usually see where the connectign
bars are... just screw in a self-tapper. How do you charge your
"country mansion" battery?

 BTW, I'm not knocking SMPS as the solution... only that it's fiddly
and you'll never actually get it working - assuming you can find a
shoe box.

Regards,
Bob
      

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