Amplifier device, audio device, and method for controlling amplifier device
AssigneeMoriyama Meiboku Co., Ltd.
InventorKazuaki Machida
Life of this patent
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Abstract
An amplifier device includes a back-EMF voltage shorting circuit between a power supply terminal located on a primary side of an output transformer and a constant potential terminal grounded. The back-EMF voltage shorting circuit is provided with a capacitor and a diode in parallel. When a back-EMF voltage input into a circuit of an amplifier device is a positive potential, a back-EMF current flows from the power supply terminal toward the constant potential terminal, and the back-EMF current is short-circuited by the capacitor at this time. On the other hand, when the input back-EMF voltage is a negative potential, the back-EMF current flows from the constant potential terminal toward the power supply terminal, and is short-circuited by the diode at this time.
Claims6
An amplifier device comprising:
- an amplifying element;
- a transformer having a primary winding for receiving an output signal from the amplifying element and a secondary winding for transmitting to a load a voice signal converted from the output signal to a predetermined output level;
- a power supply terminal connected to a power supply for supplying power to the amplifying element;
- a constant potential terminal connected to a predetermined constant potential;
- and
- a back-EMF voltage suppression circuit interposed between the power supply terminal and the constant potential terminal and provided with a diode and a capacitor arranged in parallel.
An audio device comprising:
- a speaker;
- an amplifier device including
- a transformer having a primary winding for receiving an output signal from an amplifying element and a secondary winding for transmitting to the speaker a voice signal converted from the output signal to a predetermined output level,
- a power supply terminal connected to a power supply circuit from a power supply for supplying power to the amplifying element,
- a constant potential terminal having a constant potential that is lower than an absolute value of a voltage input to the power supply terminal by a predetermined value, and
- a back-EMF voltage suppression circuit interposed between the power supply terminal and the constant potential terminal and provided with a diode and a capacitor arranged in parallel.
A method for controlling an amplifier device having a power supply terminal connected to a power supply circuit from a power supply for supplying power to an amplifying element of the amplifier device, a constant potential terminal having a constant potential that is lower than an absolute value of a voltage input to the power supply terminal by a predetermined value, and a back-EMF voltage suppression circuit, the method comprising the steps of:
- allowing a back-EMF current prompted by a back-EMF voltage to flow from the power supply terminal toward the constant potential terminal and vice versa, wherein the back-EMF voltage is generated in a load and transmitted from a secondary winding of a transformer to the power supply terminal via a primary winding of the transformer when an output signal from the amplifying element of the amplifier device is transmitted to the primary winding of the transformer and a voice signal converted from the output signal transmitted to the primary winding to a predetermined output level in the secondary winding of the transformer which is transmitted to the load, and
- suppressing the back-EMF voltage using the back-EMF voltage suppression circuit, wherein the back-EMF voltage suppression circuit is interposed between the power supply terminal and the constant potential terminal.
Dependencies are inferred from the claim text.