| 摘要 |
<P>PROBLEM TO BE SOLVED: To inexpensively provide a sensor drive circuit for stabilizing a voltage to be supplied to a sensor circuit while reducing power loss. <P>SOLUTION: A voltage detection circuit 12 outputs a voltage obtained by shifting up a voltage obtained by dividing an AC voltage to be supplied to a bridge circuit B only by a reference voltage Vref. A first comparison circuit 13 controls a first transistor Q1 to prevent the value of a positive AC voltage supplied to the bridge circuit B from exceeding a voltage Vth by comparing the voltage output by the voltage detection circuit 12 with a first comparison voltage Vc1. A second comparison circuit 14 controls a second transistor Q2 to prevent a negative AC voltage supplied to the bridge circuit B from exceeding the voltage Vth by comparing the voltage output by the voltage detection circuit 12 with a second comparison voltage Vc2. <P>COPYRIGHT: (C)2010,JPO&INPIT |
