Circuit diagrams and schematics - Electronic projects

The heart of this circuit is IC No. 555. When the alert sound was working, even though the switch will continue to be the same, the sound still does not stop immediately.But it will stops automatically, when a set time period,Depending on the resistance of R3, the circuit so I set a time period equal [...]

This is Electronic Switch, Control by Sound. It is mini Circuit and easy, use IC 1458 or 4558 or LF353 , SCR for Switch Electronic = Relay Switch. Volt supply 9V. Circuit Sound SCR Switch by IC 1458 & SCR C106D PCB Sound SCR Switch by IC 1458 & SCR C106D Source: PK Kit Circuit [...]