APPARATUS FOR DETERMINING OSCILLATING FREQUENCY ACCORDING TO DC RESISTANCE OF COIL

摘要

PURPOSE: An oscillating frequency determining apparatus is provided to allow a vibrating device to exert a maximum vibrating force by correcting a difference of DC resistance of a coil installed in the vibrating device. CONSTITUTION: An oscillating frequency determining apparatus includes a first resistance for distributing voltage. A first switch is provided to form or shut off a current between the first resistance and a vibrating device depending on a first switch control signal. A second switch is provided to form or shut off a current between the vibrating device and ground depending on a second switch control signal. The first and second switch control signals are generated from a switch control section(10). An A/D converter(14) is provided to convert voltage into a digital value. A control section(16) compares the digital value with a predetermined reference value, thereby generating a frequency control signal. A frequency generator(18) is provided to generate an oscillating frequency.