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air cannon burst switch or light switch help Answered

I am trying to build an air cannon with a circuit that opens the solenoid valve for certain amount of time (0.5 seconds) when I hold down the button, or detects, with a photo gate, when the projective leaves and shuts down the solenoid. So far I have a circuit that will shut down the solenoid when the projectile reaches the end of the barrel, but the solenoid turns back on when the projectile clears the optical sensor(optical switch). This is because I would still be holding down the button. Any tips to get the solenoid to stay turned off? It should probably stay off until I hit a reset switch.


. You need a latch on the photosensor output (will stay on after signal is lost) or a one-shot on the button (output is on for x secs, no matter how long you press).

. Unfortunately, no. :( I understand the general principles, but not the details. I'd try searching for latching relay or one-shot +elec, etc.

Would a capacitor-discharge open for as long as you wanted?