This circuit was found in 1980s American documentation. The transducer is a piezoelectric capsule and the power supply voltage can be between 3 and 18 V.
This receiver receives signals from the VHF band with earpiece or application in a power stage. The...
Originally created to power an 80's RTTY printer, this circuit can be used in other applications. The...
This circuit is from a Popular Electronics of the 90's. Any power MOSFET can be used. The circuit...