This circuit was found in Motorola documentation from the 80's. The MOSFET admits equivalent according to the current and voltage of the motor that must be controlled.
This circuit simulates a UJT, with two bipolar transistor. Frequency is given by C1 and P1...
Found in Maxim's documentation from the 90's, this circuit uses an integrated from the time...
This audio mixer was found in an old American documentation. The potentiometers are 1M and the...