metrix:
wow, looking at the prices, I could find the 1n4004 for a penny. however I can't find the tip102. Is there anything on the following link that could take it's place?
Search results for: 'servlet the %28 T %29 Transistors cln TIP Series Categories'
Or do you have a suggestion of a company that sells all the pieces needed?
I'm pretty sure ANY of the NPN transistors listed on the page would work fine. In your use, the transistor is just being used as a on/off switch. So as long as it's voltage and current ratings are well above what your circuit requires, you are golden. I think this one probably matches closest to the TIP102: Search results for: 'servlet the 72 TIP122 Transistor Complementary NPN Detail'
Lefty