Hello all, I am trying to make a simple 555 beep circuit for a game I am making for my wife's classroom. basically the game has a spinning wheel with 30 pins, kind of like a roulette wheel. when the the wheel spins the pins pass and close a switch. When the switch is closed the circuit makes a beep for only the duration that the switch is closed. My problem is that when the wheel finally stops it usually keeps the switch pressed open and the beep will not stop till you manually move the wheel to open the switch. I want the beep to only last about 1.5 seconds when the switch is closed (final resting position) but still only make a tone for the duration that the switch is closed. I put a second 555 chip (monostable) in line with the beep circuit (555 oscillator circuit) to time the pulse to 1.1 seconds, but now when the switch is closed several times within that 1.1 second period it does not beep. it can only be activated when the 1.1 seconds is up. Is there a way to interrupt the pulse using the same trigger? I am completely new to this (obviously) and am pulling my hair out. I have learned everything I know about electronics from this forum. Any help would be very much appreciated. Thank you!

 

You probably need to add a monostable, which will time the beep to whatever you want.

555 Monostable

555 Hysteretic Oscillator

The 555 Projects

 

Wow! thank you so much! I will try this out immediately. Off to Fry's for parts.

 

I have a monostable in the front. the beep is timed currently to 1.1 seconds. I just cant get it to reset if i activate the switch before the beep has run its course. The only way i can get it to reset is if I apply a voltage across pin 4. do i add the monostable to activate pin 4?

Thanks again!

 

Are you wanting to re-trigger the monostable timing the beep? That is called a (what else?) retriggerable monostable.