Applikator (TDA1028, TDA1029 Signalquellenumschalter, Vorverstärker, Audio)

The speed of a model boat can be controlled by varying the supply voltage to the main motor, via remote control. Normally, this control is fully electronic.` In .the circuit described here, however, a mechanical link is included: the remote control receiver drives a servo-motor and this, in turn, drives a potentiometer that controls the speed of the main motor.