JT> As I've mentioned in the other message, jaycar has the LM2576
JT> available as one-offs, about $14 a pop. They also have
JT> pre-wound toroidal inductors available off the shelf, hopefully
JT> the right one for your application. 

 You and Brenton need a reality check. David's not going to *ever*
finish building this thing. You've got to be practical. Even my idea
of a 6V bike battery and a 5W light bulb is a bit over the top. He'll
have to plug it into a the cigarette lighter, and if David's anything
like me, he'll buy the plug and never wire it up.

 SMPS on a PCB? Get real!

JT> Efficiency might be an issue, I'm using one on 5v equipment at
JT> about an amp (or just over actually), the heatsink is 5cmx5cm
JT> thinnish aluminium plate mounted within the case. It gets warm
JT> if it's been on for a while, but well within specs. At 3 amps a
JT> larger heatsink would be wise. A larger coil wouldn't go astray
JT> either. 

 Yair. These little fuckers are 50% efficient if you're lucky, and
the smaller they get the worse they are. He'll lose 10W+, which is why
I suggested an ordinary series regulator as a viable possibility. He
can just wire the whole thing onto the heatsink and put it in a shoe
box with his other inverter.

Regards,
Bob



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