Patent ID: 8004225
Filing Date: 2011-08-23
Classification: H02P

Abstract:
1. A drive control circuit that controls an electric motor having a magnetic coil, comprising: a driver circuit having a switching element that turns on/off a connection between the magnetic coil and a supply voltage supplied from an external power supply, thereby intermittently supplying the supply voltage to the magnetic coil; a switching signal generating circuit that generates a switching signal for use in on/off control of the switching element; and a supply voltage setter that supplies the switching signal generating circuit with a supply voltage control value which is related to the supply voltage; wherein the switching signal generating circuit adjusts an effective voltage applied to the magnetic coil by adjusting a pulse width of the switching signal according to the supply voltage control value such that the effective voltage applied to the magnetic coil assumes a prescribed constant value irrespective of the value of the supply voltage, and wherein the switching signal generating circuit includes: