Solar intercom (CB20503E)

This circuit can be used in demonstrations or science fairs. The circuit uses headphones and can be powered by solar cells.

Amplifier for Earphones II (CB975E)
The circuit shown is an amplifier for medium impedance headphones including bass and treble...
DC Motor Control (CB17555E)
This is a direction of rotation control for a small motor up to about 2 A with the indicated...
Wien II Bridge Oscillator (CB4924E)
This circuit generates signals from 0.01 Hz to 10 kHz, but uses unusual components today. The...