Simple siren (CB21663E)

This transistorized siren was found in Popular Electronics from April 1967. The signal must be applied to a good audio amplifier.

High Speed Single Pulse (CB6351E)
This high-speed circuit was found in 1980s Linear Technology documentation. The circuit makes use...
TwoTransistor Amplifier (CB987E)
The transistors of this amplifier for 8-200 headphones may be the BC548 or equivalent to replace...
Pulser with relay (CB23666E)
The frequency of this pulser depends on the capacitor and the characteristics of the relay. The...