This is the traditional H bridge configuration for motors. The circuit is for currents up to 500 mA, but with higher power transistors such as the TIP31 motors up to 2 A can be controlled.
This common gate circuit for the 13 to 30 MHz band was found in old English documentation....
This circuit was originally found in a Philips documentation from 1969. It is intended for sensing...
This FET voltmeter is from an old 1974 amateur radio publication. The circuit can use MPF102 or...