I'm attempting to make a simplistic solenoid driver circuit using a standard astable 555 timer configuration with a TIP122 NPN transistor. The problem with the current circuit is that the output is typically high and goes low only for short durations. I'd like to invert this but I'm not sure how.
Ideally I would like a high output every 1 second that lasts only for 100ms.
Do I just need to change RC values or utilize the 555 differently?
(The schematic shows a 556, which is what I am currently using. The lamp-looking squiggle is the solenoid and I have added a 1N4001 diode across it in reverse bias.)