I'm trying to control a small circuit by triggering a relay via an arduino output, I've following the suggestions here (http://blog.makezine.com/2009/02/02/connecting-a-relay-to-arduino/
) so my setup looks as like this...
R1 - 1k
T1 - I've tried both 2n3904 & BC5480
RL1 - Rayex Elec LU-5 5V DPDT Relay (http://www.maplin.co.uk/2a-dpdt-bt-type-47-equivalent-relay-37522
I have output pin 7 set to turn on and off every 2 seconds, if this pin is wired as in the diagram the relay coil doesn't get activated?
Even though the relay is rated at 5v it only appears to get triggered by 3.3v or the arduino output pins not the 5v run.
If I bypass the R1 and T1 and run output 7 directly to the relay coil, the relay is triggered and everything works however I'm concerned about burning out my arduino with the resistor and transistor being there for a reason. Is it safe to run it directly off the output pin?
Many thanks for your help in advance, this is my first project!