Found in Radio Electronics from the 90s, this circuit uses components from that time. However, it can still be elaborated with some ease.
This small fluorescent lamp inverter (up to 20 W) can be powered by 12 V battery and even less. The...
This small-range MW transmitter can be used as a wireless microphone. The circuit is from an...
This simple circuit was found in Popular Electronics. It can be built with any JFET. Galvanometers from...