| 摘要 |
PROBLEM TO BE SOLVED: To reduce the current consumption of a pseudo-inductance circuit which fetches a constant voltage from DC power upon which a prescribed AC signal is superimposed. SOLUTION: A pseudo-inductance circuit fetches DC power from an input signal upon which a speech signal and the DC power are superimposed by increasing the impedance of a transistor Q1 against the input signal and decreasing the impedance in accordance with the frequency of the DC power. The operation of the inductance circuit is controlled so that the electric current I1 flowing to the transistor Q1 can correspond to the output current I2 to a connected load by supplying a bias current to the transistor Q1 in accordance with the output current I2 by operating transistors Q2-Q4 by means of a comparator 25 which monitors the collector voltage of the transistor Q1. |
