Ive been using a 2N5064 SCR as a switch for a light. Could I also use a 2N3904 transistor to do the same thing? Do they function the same?

 

Google "scr" and see how it works and what it does. Google "transistor" and see how it works and what it does. Compare the two and see if they are even remotely close.

 

No, an SCR stays on once triggered. The Transistor would only light for the short duration while triggered (whatever pulse is used to trip SCR currently).

Would need to see a schematic to let you know all the details for sure.

 

A 2N3904 and 2N3906 might be used. Search on making an SCR from transistors.

http://www.allaboutcircuits.com/vol_3/chpt_7/5.html

John