Fr Robert Ballecer, SJ You probably just misspoke on episode #83, but you can 't control an ac...

[G+_610GARAGE]

Fr. Robert Ballecer, SJ You probably just misspoke on episode #83, but you can't control an ac power source directly from an transistor. You would need a relay. Or if you need faster switching speed, use an apto coupled triac, attached to another triac. The opto coupling may not be nessesry, but it does protect the controller. This is the setup that I used when I was fiddling with dancing Christmas lights.

 

While I'm nitpicking, :) it wouldn't be a bad idea to put a small heat sink on the transistor running your lights, since you are running the transistor in its transient state a lot.

[G+_Fr. Robert Ballecer, SJ]

With a device that allows you to drive higher voltage applications with a much lower voltage, you can then drive a relay for home automation.

 

The 3 and 5v headers on a pie are not alone capable of tripping most "home appliance rated" relays.

 

Peace,

Padre

[G+_610GARAGE]

Fr. Robert Ballecer, SJ Thanks for clearing that up. I should have figured that's what you meant, but when you I heard you, I had a flash back to when I fried my favorite computer by accidentally mixing up power and ground on a project, and sending 24 volts, reverse polarity, through my usb port, via a usb oscilloscope. I guess it traumatized me. :) My computer case still has the burn mark from the capacitors literally blowing up on the back of my motherboard. I still miss that dual zeon cpu computer. =( Although, something like this could only happen if the pie was powered by a computer.