Hi John



 RM> terminal to give it continuous power. Before its fuse popped, a

 RM> tantalum cap protected the power supply from the 240 by shorting

 RM> with a bang. I like tantalums. (Hi Brenton!)



 JT>  At least you know which one blew.  I've come across the bloody things that

 JT> were shorted with no physical signs of stress.  It was a bugger to find.

 JT> :-(



Trick: to help find a shorted cap on a rail that has dozens of

candidates, connect a power supply to the rail, voltage set to

something below the rail's normal level, and current limit set to

something low, start off at say 200mA. Connect neg lead of

multimeter to neg connection, then use the pos lead to hunt

millivolts down the tracks. Look for caps with the same voltage on

both leads. Increase the current if the drops along the tracks

can't be detected, but watch out for heating. Don't try winding up

the current and looking for hot caps, shorted tantalums often

conduct better than the tracks around them.





 RM> Regulation: The simplest way would be to depart from the rigid sine

 RM> specification, and just alter the pulse widths in a fudgy way, eg

 RM> 



 JT> Blotching up the sine wave like that defeats the purpose of having

 JT> a sine inverter in the first place. Sure it would be cleaner than a

 JT> square only, but if you go the trouble of making a sine output

 JT> inverter, you may as well actually USE a sine wave. :-)



not if it's too expensive or complicated. Remember my ancestry, and

the copper wire legend (see The Profiles on Aunt Teddy's homepage)





 JT> If it is just a square wave, you don't really need a PIC, as it can

 JT> be done cheaper with garden variety components.



 RM> Marginally cheaper. A PIC and crystal is typically less than $15.



 the newer 8 pin 12C5xx PICs are $1.50 each in lots of 10. I

think I'm in love...



Cheers



--- PPoint 1.88