Balanced Modulator MC1594 (CB14588E)

This circuit is from the Motorola Linear Databook from 1990. The integrated circuit used is uncommon today.

TTL Digital Lotto (CB11514E)
This circuit, which draws numbers from 00 to 99, was found in an Italian magazine from 1974, but...
Phase Inverter Using One Transistor (MSB024E)
This circuit produces two signals with inverted phases. One is taken for the emitter of Q1 and the...
Exclusive OR function with Relay (CB19776E)
For this function, a little more sophisticated, we need switches (keys) or double sensors. This is...