Suggested by Motorola documentation from the 1980s, this circuit can be implemented with equivalent power MOSFETs. The type depends on the current of the controlled motor, as well as the diodes.
This circuit is from a 90s Popular Electronics. It consists of a power source for bass amplifiers...
The maximum time of this timer depends on the capacitor next to the adjustment pot. With 2,200 uF the...
The operational amplifier used in this circuit admits an equivalent, since the circuit is from old...