| 摘要 |
PURPOSE: A speaker current controlled audio amplifier is provided to control the current of the speaker directly using an inverter which has a circuit structure of a bridge-form and uses switching elements in an upper arm and lower arm thereof. CONSTITUTION: A volume controller controls an output volume by adjusting a gain on the basis of a feedback current. A current controller compares the output from the volume controller and a reference current using an operation amplifier(OP Amp) and determines current to be inputted to a speaker. A compare device is supplied with the reference current. The compare device determines a polarity of the current. A logic circuit device is comprised of a plurality of logic element. The logic circuit device outputs a switching signal that minimizes a dead time for operating an upper arm switching element and a lower arm switching element alternatively on the basis of the output signals from the current controller and the compare device.
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