u/DeathByOven

Op amp to timing circuit

Hello,
I wasn't able to attach my circuit schematics in my previous post so heres an updated one.
I’m using a 556 dual timer IC with an op amp comparator as the input. The intended behaviour is when op amp output is low, a buzzer should be continuously on and when op amp output goes high, the buzzer should be on for roughly 5s then turn off.
Ive setup my op amp output to feed the 556 monostable trigger input. Monostable output to 556 astable reset pin. Then astable output to drive the buzzer. Im using 50k resistor with 100 uF capacitor.
My current issue is that when switch is flipped to 5V for more than the intended timing (5s) and back down to ground, it shuts down instantly rather than going for a further 5s.

u/DeathByOven — 8 days ago

▲ 0 r/AskElectronics

Op Amp to Timing circuit

Hello,
I’m using a 556 dual timer IC with an op amp comparator as the input. The intended behaviour is when op amp output is low, a buzzer should be continuously on and when op amp output goes high, the buzzer should be on for roughly 5s then turn off.
Ive setup my op amp output to feed the 556 monostable trigger input. Monostable output to 556 astable reset pin. Then astable output to drive the buzzer. Im using 50k resistor with 100 uF capacitor.
My current issue is that this configuration shuts down the buzzer immediately after op amp output turns high. Ive tried adding an RC circuit to the op amp output but the nothing changed.

reddit.com

u/DeathByOven — 8 days ago