| 摘要 |
PROBLEM TO BE SOLVED: To provide an acoustic amplification device that dispenses with a negative feedback path. SOLUTION: A voltage depending on an acoustic signal S1 output from a signal source 10 appears at a connection point CP of a positive power amplification section 14. A differential amplifier 16 holds a voltage at an emitter electrode of an NPN transistor 18 that is the same voltage at the connection point CP. A current depending on the acoustic signal S1 thus flows through an output current decision resistor Re and an output resistor RL. As for a negative power amplification section 14N, a current depending on the acoustic signal S1 flows through an output current decision resistor ReN and the output resistor RL on the same principle as in the positive power amplification section 14. A signal voltage based on a signal current Si2 flowing through the output resistor RL in the positive power amplification section 14 and a signal current Si4 flowing through the output resistor RL in the negative power amplification section 14N is output from a signal output terminal TO. COPYRIGHT: (C)2013,JPO&INPIT |
