This powerful siren is suitable for warning or alarm systems. The components are current and the transistor 3055 must be mounted on a good heat sink.
This common emitter amplifier with 43 dB gain was found in the August 1970 issue of Radio...
The diagram below is an application of the Texas Instruments TPS25221 to an ISM controlled power...
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...