Patent ID: 6035960
Filing Date: 2000-03-14
Classification: B62D

Abstract:
A motorized power steering control device comprising:an electric motor for providing steering assisting force;a controller for controlling said electric motor;a battery connected to said electric motor and said controller for driving said motor;an alternator arranged in association with an engine and connected to said battery;a travel condition detecting means connected to said controller;said controller including a drive circuit for varying a voltage applied to said electric motor and a control circuit connected to said travel condition detecting means for controlling said drive circuit depending on a travel condition detected;an alternator pulsation detecting circuit arranged in said controller for detecting a pulsation frequency of the alternator;a power circuit arranged in said controller for applying a main voltage or a backup voltage to said control circuit while selectively controlling said main voltage or backup voltage, the alternator and said battery being fixedly and simultaneously coupled through a common wire to said power circuit such that the alternator pulsation frequency is superimposed on the battery voltage;each of said control circuit, power circuit and alternator pulsation detecting circuit being integrally arranged and connected within said controller for eliminating an external connection between an ignition switch and said controller;said control circuit being structured and arranged to calculate the speed of the engine based on the detected pulsation frequency of the alternator;said control circuit actuating said power circuit to permit the main voltage to be applied to said control circuit when the calculated engine speed is at a predetermined level or above and permit the backup voltage to be applied to said control circuit when the calculated engine speed is at the predetermined level or below.