JPS6128261A - Power supply for acoustic equipment - Google Patents

Abstract

PURPOSE:To prevent disturbance of a telephone call response by adopting the constitution that a power supply of an acoustic equipment allows power supply to stop automatically in response to a sound raised by a telephone set. CONSTITUTION:A telephone pickup installed at a suitable place of the telephone set is cnnected to an input terminal 3 and when a telephone call comes externally and bell rings, or a handset is hooked off and talking is started, the telephone pickup detects a low frequency signal of a telephone set and the signal is amplified by an amplifier circuit 4. The amplified low frequency signal gives an electric charge to a timer capacitor 15 by the operation of an input capacitor 13 and a transistor 14 to boost a terminal voltage. Thus, the DC voltage fed to the acoustic equipment 2 by the operation of the relay circuit 5 is interrupted by a relay contact 12 and the voice generated from a speaker 11 is stopped. Further, timer function 6 acts on keeping the said voltage off for a prescribed time even if the talking is intermitted.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a power supply device that is built into or attached to an audio device such as a radio or tape recorder for use near a telephone.

BACKGROUND ART Radios, tape recorders, and other audio equipment have increasingly been used as background music for work and play. At times like this, calls often come in, and in most cases, when answering, the person answers the phone with the audio equipment turned off in order to be able to speak clearly to the person on the other end.

This invention was made with this kind of use in mind, and automatically stops the use of the audio equipment. To explain this with reference to the diagram as an example, ■ is a method for connecting a low-voltage DC power source from an AC power source. It is a converter for obtaining AC power, and is composed of a terminal (plug) 7 for connecting to an AC power source, a transformer 8, and a rectifier 9.

2 is an audio device such as a radio/tape recorder that is operated by the DC power obtained from the converter 1;
0 and a speaker 11. 3 is a telephone pickup input terminal, 4 is an amplifier circuit for amplifying the signal of the input terminal 3, and 5 is a relay circuit operated by the output signal of the amplifier circuit 4. The power supply device has configurations 1 to 1. 12 is the relay circuit 5
This relay contact switches to cut off the power to the audio equipment 2 when a telephone pickup input signal is detected.

6 is a timer function provided in the relay circuit 5, input capacitor] 3.1 - consists of a transistor 14 and a timer capacitor 15, and the low frequency output of the amplifier circuit 4 is connected to the transistor 14 via the capacitor 13. It becomes conductive and increases the terminal voltage of capacitor 15 for the timer. 1
A diode 6 associates the Beine voltage of the transistor 14 with the emitter voltage, and serves to efficiently increase the terminal voltage of the capacitor 15.

The timer capacitor 15 is slowly discharged through the transistor of the relay circuit 5, and during this time the relay contact 1
2 is held open.

Further, 17 is a constant voltage device for the amplifier circuit 4.

To explain the use of this invention consisting of the second configuration, when the terminal 7 of the converter 1 is connected to a household AC power source, the transformer 8 and rectifier 9 act to obtain a DC voltage of 11, which can be used in radios, tape recorders, etc. can play audio equipment.

In addition, the telephone pick amplifier installed in the appropriate place on the telephone is connected to input terminal 3, and when a call comes in from outside and the bell rings, or when you pick up the receiver and start talking, the telephone pick-up is connected to input terminal 3. The low frequency signal is detected and amplified by the amplifier circuit 4. This amplified low frequency signal stores charge in the timer capacitor 15 through the action of the input capacitor 13 and transistor 14, thereby increasing the voltage between the terminals. Therefore, the DC voltage supplied to the audio equipment 2 is cut off by the relay contact 12 due to the action of the relay circuit 5, and the sound generated from the speaker 11 is stopped.

Therefore, power is not supplied to the audio equipment 2 while talking on the phone, and the sounds of the radio, cheap recorder, etc. no longer interfere with the conversation on the phone. Furthermore, the function of the timer function 6 is to stop the sound of the radio/tape recorder for a certain period of time (30 to 60 seconds) even if the speaking voice is interrupted, so that the radio/tape recorder will suddenly turn off even if the speaking voice stops for a short period of time. This is to prevent trouble from occurring.

As described above, in this invention, even if you receive a phone call while listening to the radio or tape recorder, if you answer the phone without turning off the audio equipment, the sound emitted from the speaker 11 will automatically stop. As a result, the ease of handling audio equipment has been greatly improved.

As an embodiment of the present invention, it may be directly incorporated into the power supply section of the main body of an audio equipment that uses an AC power supply, and in the case of an audio equipment that uses a DC power supply using an AC adapter, the power supply section A, 0 may be installed. It can be incorporated into an adapter or
, may be configured as a single unit independent of the C adapter,
Furthermore, for audio equipment such as tape recorders, instead of shutting off the power to the entire equipment, it is recommended to use a system that shuts off the power to only the audio circuit of a portion of the monitor while leaving the recording section energized during an air check. You can choose an easy-to-use configuration that suits your device.

[Brief explanation of drawings]

The drawing shows a circuit showing an embodiment of this invention. 1...AC/DC converter 2...Audio equipment 3...Telephone pickup terminal 4.
...Amplifier circuit 5 ...Relay circuit 6
・・・・・・Timer function installed in the relay circuit

Claims (2)

[Claims] (1) In a power supply device for audio equipment 2 such as a radio or tape recorder that uses a converter 1 to obtain low-voltage DC power from an AC power supply, the power supply device has a telephone pickup input terminal 3 and an input terminal. This audio equipment is provided with an amplifier circuit 4 for amplifying the signal of No. 3 and a relay circuit 5 operated by the output signal of the amplifier circuit 4, and the relay circuit 5 cuts off the power to the audio equipment 2 when a telephone pickup input signal is detected. power supply. (2) The power supply device for audio equipment according to claim 1, wherein the relay circuit 5 is provided with a timer function 6, and when the telephone pickup input signal goes undetected, the power supply is further cut off for a certain period of time.