| 摘要 |
PROBLEM TO BE SOLVED: To reduce and suppress rotation noise, kickback voltage, crossover distortions, and through-currents by using a simple circuit configuration. SOLUTION: First and second operational amplifiers 1 and 2, which are constructed so as to carry out pushpull amplification, are provided, and the output signal of a Hall element 5 is amplified by the respective amplifiers 1 and 2 and the output signals of the amplifiers 1 and 2 which have phases opposite to each other are applied to a motor 7. The through-rate of the output signal is made possible, by properly selecting resistance values of a first feedback resistor 3 and a second feedback resistor 4. Particularly, pushpull amplifiers comprising C-MOS transistors are constructed in the final stages of the first and second operational amplifiers 1 and 2. Further, the gate voltages of the C-MOS transistors are shifted to proper values of offset stages provided in previous stages, so that a crossover distortion and a through-current can be suppressed. |
