Abstract: A start circuit for an induction motor having a main winding and a start winding includes a sensor of main-winding current. A detector detects the level of main-winding current sensed by the sensor. The start circuit includes a reference generator driven by the level detector and providing a reference level proportional to an average value of main-winding current. The reference level can vary slowly in accordance with a long-term drift in magnitude of the main-winding current. A switch energizes and deenergizes the start winding in accordance with relative values of a signal of the detector and the reference level, thereby allowing for automatic restarting in the event of a sudden increase of current due to a motor stall.

Abstract: An energy saving arrangement in which motors performing mechanical work in automatic pin spotters are disconnected from power lines when a bowling play is discontinued after a predetermined time interval. A time delay relay is repeatedly actuated by a circuit connected to the rake latching bar. The time delay relay maintains a control relay energized provided that the rake latching bar actuates the circuit to the time delay relay within a predetermined time interval. If no such actuation takes place, then the control relay is released and the power motor for the pin spotter is switched off. The motor controlling the speed of the ball toward the bowler is similarly switched off after a predetermined time delay from the instant that the ball actuates a switch on its way back to the bowler or after a predetermined time delay after the rake latching bar is released. A capacitor bank is provided, furthermore, to correct the power factor of the energy applied to the motor and thereby results in energy savings.