My goal is to make a car turn signal flasher. I used a 555 chip as the timer with the output driving a TIP122 transistor at BASE and a 100 ohm resistor between the BASE and the 555 output pin 3. The Emitter is connected to ground. The Collector is connected to one side of the the relay coil (90 ohms) and the other side of the coil to ground. Simply will not cycle. Tried different base resistors 100 to 2000 ohm. Transistor NOT switching.
BTW the flasher circuit works fine when driving an LED only. (no transistor, relay etc).
Any ideas?