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 circuit is suggested by National Semiconductor in its Linear Applications Handbook. It makes...
We found this circuit in an old Radio Electronics. The transistors can be the BC548. The circuit...
Using two LM377s, this amplifier provides a few watts of audio in a low impedance speaker and the power...