This circuit was found in a Motorola documentation from the 70s. The integrated circuit is from the time, an operational power amplifier according to the controlled motor.
The circuit in the figure is based on an LM101A; diodes can be replaced with equivalents. The...
This circuit, with magnetic sensor, uses an operational amplifier of the time. The circuit is from...
Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is...