We found this circuit in an 80's Radio Shack publication. The circuit uses a company buzzer, but modern equivalents can be employed according to the power used. The SCR can be the TIC106 and the transistor the BC558.
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We found this circuit in an 80's Radio Shack publication. The circuit uses a company buzzer, but modern equivalents can be employed according to the power used. The SCR can be the TIC106 and the transistor the BC558.