JPPadula
Newbie level 2
I'm trying to create an automotive flasher using a 556 timer (only using 2nd half layout was easier using second half, nothing done to any part of first half) Followed the standard schematics and am fairly certain I've got it wired properly. I tried using a 47uf and 22uf Capacitor and varying resistance values between 20k and 80k for R1 and R2 (I used the calculators and am trying to achieve around .5Hz with a 75% duty cycle) I'm using the output of the IC to drive a an automotive 80ohm coil relay directly and have installed diodes both across the coil and forward biased in the output to the coil. I have 470uf cap across the power supply for decoupling, and have tried a .1uf cap to ground on the control wire. The problem is that as soon as the power is applied, the relay coil latches and never oscillates. I dont own a scope, but on some of the pins (forgot which right now) I can see the charge discharge of the cap and the rate changes with the resistors being adjusted. Any advice on how to troubleshoot?