Call alert

We have designed this circuit, very simple indeed, which can be used in a sanatorium doctor, a college or school.

In the case of the sanatorium so that patients can call the nurses, in schools and colleges, so the director call the teachers of each section.

It consists of push buttons, diodes and capacitors buzzers, the latter two are the warning signs. I hope that it can be useful and you can find other applications.

OPERATION: When you press a button, completes the corresponding ciruito loading the capacitor, which led the ignition and kept ringing the buzzer for a few seconds. The time depends on the ability of the capacitor, a larger capacity more time.

Capacitors
C1, C2, C3: Electrolytic capacitors of 1000 µF. or more
Semiconductor :
D1, D2, D3: red LEDs
Resistors:
R1, R2, R3: 600 Ω
Other
SW1, SW2; SW3: Pushers common type timbre
feed the circuit with a battery or power supply 9 volt.

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