Thanks mursal. The 555 drives a transistor which drive a 12 volt mini relay which drives the 1.6A actuator.
Back emf from the relay coil is not a problem. the problem lies with the back emf from the actuator. However I've added a snubber across the actuator but that still doesn't help.
Thanks Hunter, The actuator is a simple door lock that move in and out by 0.5 inch and uses 1.6A at 12 volts. But the Back EMF from the actuator are interfering with the 555 timer operations because they both use a common ground. However the 555 are powered by a 7 volt variable lm317 regulator.
Yes - You're right. but I need a circuit to operate it. The alarm will sink a pulse of -1mA to trigger a 2 pulse square wave.
I have a schematic but this website won't let me upload a jpg of the circuit.
I also build a prototype using a breadboard and the circuit works perfectly except when I...
Need Help with a 12 volt car actuator circuit. I will use my car alarm to open the trunk but I need to install the actuator and the circuit. The car alarm has a wire that will accept up to -500mA of current when I push a button on my keys. That will be the trigger to trigger the circuit I need...