mramos1 said:
But I do not think I will beat Bill, now if I had an 877 laying around. hahaha..
I've got a hand wired version works like a charm does that count?, my PICStart is collecting dust. These ICD2s are so much faster at programming.
I also use a 5v switch mode wall adapter, love it. Hate LM7805s but they're common and you can sub it with scads of better parts.
I've sent the design off to China, although the locals (Toronto) are good I want to make sure the drill data is spot on so a small run of 50 seems right.
In Toronto qty 250 they work out to $2.50 each Single sided is the way to go if you can.
I've had zero luck with the A parts, perhaps they're too slow (not marked -20 does that make them 4MHz) The stores in Toronto don't know what speed they sell
Least I can get those funky BC548B & BC558B transistors, I do prefer 2N39xx though.
Lastly the voltage multiplier works like this...
VIN (+5V)
VIN * 2 (the max232) - the two diode drops in the max232 0.3*2 = 9.4V
then the 1.5 multiplier D5, D6 & C8
VPP = 9.4 * 1.5 - 0.7 * 2 = 12.7V
Then subtract Q3 ~ 0.6v you'll get 12.1V
It's worked on all the PICs I've thrown at it. If you think you need a higher VPP use 1N5819s for D5 & D6.