Arduino and a SCR

[twilliamson]

Im working on a application were I need to switch a device (a lightbulb 2 amps @12v DC). I only need to switch it on(i understand that a SCR only conducts once, current has to be removed for it to reset, that's desirable for my application) , Im looking for the simplest way, as well as the most compact package possible. I've explored just using a transistor or a fet but don't like those options too much. I need to be able to switch the positive side of the load also, ground switching wont work. My question is will a C106D SCR work. I know there will be extra inrush but i believe per the specs i should be within the limits of this part. My next question is how exactly does something like this interface with a Arduino? From what im guessing it just needs a current limiting resistor to the Gate of the SCR and things would, should work?

[john444]

Hi T,

Positive side switching becomes a little more complicated than ground switching.
But, you have chosen a good part. The C106 is a reliable, sensitive-gate SCR.
I have never done this but with the 20-mA output limit of a Arduino,
I expect that you will need to transformer couple to the gate.
A 600:600 telephone coupling transformer should do.
They are readily available, fairly small and provide the level-shifting you need
for the high-side switching / drive for the C106.

Good Luck, John