Need direction to fix water level indicator buzzer problem

[Johnson007]

I am just a hobbyist recently I build a basic model which resembles something like this circuit to stop water overflowing problem & it seem to solve the problem but i need to cut the power when i hear the buzzer as it keeps on buzzing until the water level doesn't goes down. How should i solve this problem ? Like stop the beep after like say 1 minute so that i don't have to cut power .

 

[crutschow]

What's the battery voltage?
How much current does the buzzer take?

 

[KMoffett]

This is a circuit that I've used. Probes in water trigger the SCR on with a pulse through the capacitor. Shorting the SCR with the push button switch silences the alarm. When the water level drops below the probe the 1M resistor discharges the capacitor, ready for the next flood. A normally closed between the SCR'c anode and the buzzer also works. The SCR should be the "Sensitive Gate" type.

Ken

 

[chemelec]

Add a 555 Timer to the Circuit to shut it off after One Minute.
Shouldn't be too difficult.

 

[crutschow]

You can probably just do it with a MOSFET in place of the BJT and an RC delay.

 

[dr pepper]

Yes a 555 ought to do the trick.