| 摘要 |
PROBLEM TO BE SOLVED: To achieve a simple passive circuit to which a self-restrictive effect in power reduction is required on a power supply circuit, since, in an impedance rising area of a speaker minimum resonance frequency, a typically used low voltage output amplifier is subject to current reduction and particularly a sealed type speaker system hardly generates a bass sound.SOLUTION: Power supply reduction is suppressed by making a speaker current to flow in a secondary coil L2 of a transformer and making an amplifier current to flow in a polarity inverse to the current of the secondary coil L2 to generate a difference in the cancellation of inductance caused by current reduction of a speaker so as to cancel out mutual inductance, which generates a secondary coil L2 voltage to be added to an input voltage. |
