Amplifier, audio device and control method

• US 10,630,240 B2
• Filed: 08/29/2018
• Issued: 04/21/2020
• Est. Priority Date: 09/06/2017
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Goto, Mitsutaka
• Primary Examiner(s): Nguyen, Patricia T
• Application Number:
  US16/116,243
• Publication Number:
  US 20190074798A1
• Time in Patent Office: 601 Days
• Field of Search: 330136
• CPC Class Codes: G01R 19/16538 in AC or DC supplies G01R19/16519 and G01R19/16528 take precedence
• CPC Class Codes: G10K 11/36 Devices for manipulating acoustic surface waves electro-acoustic amplifiers H03F13/00; networks comprising electro-acoustic elements H03H9/00
• CPC Class Codes: H03F 1/0222 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/52 Circuit arrangements for protecting such amplifiers monitoring arrangements G01R31/28; increasing reliability in communication systems, e.g. using redundancy H04B1/74
• CPC Class Codes: H03F 2200/321 Use of a microprocessor in an amplifier circuit or its control circuit
• CPC Class Codes: H03F 2203/7227 the gated amplifier being switched on or off by a switch in the supply circuit of the amplifier
• CPC Class Codes: H03F 3/181 Low-frequency amplifiers, e.g. audio preamplifiers
• CPC Class Codes: H03F 3/20 Power amplifiers, e.g. Class B amplifiers, Class C amplifiers H03F3/26 - H03F3/30 take precedence
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H03G 3/004 Control by varying the supply voltage
• CPC Class Codes: H04R 2227/005 Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407

Abstract

An amplifier includes a power amplifier that amplifies an input signal, a VI detection circuit that is connected to a rear stage of the power amplifier to detect power of an output signal of the power amplifier, and a controller that turns on the power amplifier when the input signal is inputted to the power amplifier, turns off the power amplifier when the input signal is not inputted to the power amplifier, and turns on the power amplifier when the VI detection circuit detects a voltage that exceeds a predetermined value when the power amplifier is in off state.

Claims

1. An amplifier comprising:

a power amplifier that amplifies an input signal;

a VI detection circuit connected to a rear stage of the power amplifier and that detects power of an output signal of the power amplifier; and

a controller that, in a state where the power amplifier is OFF, turns ON the power amplifier when the VI detection circuit detects a voltage that exceeds a predetermined value.

2. The amplifier according to claim 1, further comprising:

an input detection circuit connected to a front stage of the power amplifier and that detects a level of the input signal to the power amplifier,

wherein the controller;

based on the level detected by the input detection circuit, determines whether the input signal is detected;

in a state where the power amplifier is OFF, turns ON the power amplifier when the input signal is detected; and

in a state where the power amplifier is ON, turns OFF the power amplifier when the input signal is not detected.

3. The amplifier according to claim 2, wherein the controller, in a state where the power amplifier is ON, turns OFF the power amplifier when the input signal is not detected for a duration longer than a predetermined time.

4. The amplifier according to claim 1, further comprising a signal processing circuit that applies a predetermined signal processing to the input signal.

5. The amplifier according to claim 1, wherein the amplifier:

is connectable to a plurality of speakers; and

includes the power amplifier and the VI detection circuit for each of the plurality of speakers.

6. An audio device comprising:

an amplifier comprising;

a power amplifier that amplifies an input signal;

a VI detection circuit connected to a rear stage of the power amplifier and that detects power of an output signal of the power amplifier; and

a controller that, in a state where the power amplifier is OFF, turns ON the power amplifier when the VI detection circuit detects a voltage exceeding a predetermined value; and

a speaker that receives the output signal and emits sound.

7. A control method for an amplifier that amplifies an input signal, the method comprising:

detecting power of an output signal of the power amplifier from a rear stage of the amplifier; and

controlling powering of the power amplifier, in a state where the power amplifier is OFF, by turning ON the power amplifier when the detecting of the power detects a voltage that exceeds a predetermined value.

8. The control method according to claim 7, further comprising:

detecting a level of the input signal to the power amplifier from a front stage of the power amplifier; and

determining whether input signal is detected based on the detected level of the input signal,

wherein the controlling of powering;

in a state where the power amplifier is OFF, turns ON the power amplifier when the input signal is detected; and

in a state where the power amplifier if ON, turns OFF the power amplifier when the input signal is not detected.

9. The control method according to claim 8, wherein the controlling of the powering, in a state where the power amplifier is ON, turns OFF the power amplifier when the input signal is not detected for a duration longer than a predetermined time.

10. The control method according to claim 7, further comprising applying a predetermined signal processing to the input signal.

11. The control method according to claim 7, wherein:

the amplifier is connectable to a plurality of speakers,

the amplifier includes the power amplifier for each of the plurality of speakers, and

the controlling of the powering, in a state where the power amplifier is OFF, turns ON the power amplifier for each of the plurality of speakers when the detecting of the power detects the voltage that exceeds the predetermined value.