Alarm sound with control switch.
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 to 1M for 1 minute 6 seconds.
The output of IC 555 is triggered by a positive voltage on pin 2,when all switches are connected together.When the something switch is cut off pin 2, it will be negative voltage and the trigger IC 555 will stop. The C1, C4 to protects a noise signal from either switch, which may cause the alarm to be up. This circuit can be used with power supply from 5V to 15V depending on relay sure enough.
Categories: Alarm systems Tags: 555 alarm circuit, simple alarm circuit, Sound-Switch
Sound SCR Switch by IC 1458 & SCR C106D
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.
You can see LF353 in many circuits.
Circuit Sound SCR Switch by IC 1458 & SCR C106D
PCB Sound SCR Switch by IC 1458 & SCR C106D
Source: PK Kit Circuit
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Categories: Circuit diagram, Electronic Control Tags: scr control circuit, sound activated switch, Sound-Switch
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