I have been experimenting with my Arduino Duemilanove for a month.
Last week I bought a PowerSwitchTail (www.PowerSwitchTail.com) from AdaFruit. My question: How many of these PowerSwitchTail can I run from my Arduino Duemilanove? I know I will need a separate PowerSwitchTail for each water valve I wat to turn on and off.
--- Thanks nickynichols
See the transistor drive circuit at the lower left here?
http://powerswitchtail.com/Documents/PST%20Instructions%20v1.03.pdf
How many I/O pins do you have? How many more can you add via shift registers?
The qty is really limitless.