JPH0634043B2 - Power control device by timer of audio device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timer-based power supply control device for an audio device, and more particularly to a timer-based power supply control device for an audio device suitable for a wake-up function.

[Conventional technology]

The power control device by the timer of the conventional audio device is
For example, Japanese Examined Patent Publication No. 54-44590 and Japanese Examined Patent Publication No. 54
As disclosed in Japanese Patent Laid-Open No. 42579/1992, the power supply of the device to be controlled is simply turned on or off at the time when the timer is set to emit or stop the audio demodulation signal (hereinafter, simply referred to as an audio signal). It was only controlled. That is, conventionally, when the power of the audio device is turned on by the timer, no particular consideration has been given to the magnitude of the audio signal level.

[Problems to be solved by the invention]

Therefore, in the above-mentioned conventional technique, when the audio signal level at the time of turning on the power of the audio device is high, for example, there is a problem that a user who wants to wake up by the audio device gives an unpleasant feeling.

An object of the present invention is to provide a timer for an audio device which does not cause a discomfort to the user when the audio device is turned on by the timer without rapidly turning on the audio signal at a high level. It is to provide a power supply control device.

[Means for solving problems]

The above-mentioned object is that the output signal of the amplifier circuit for driving the speaker is cut off in advance by the output switch, the power of the audio device is turned on at the time set by the timer, and the signal is supplied to the amplifier circuit at a certain time from the time. When the audio signal level is detected and the silent pressure interval is detected, the output switch is turned on in this section, while when the silent section is not detected, the audio signal level is once lowered. This is accomplished by turning on the output switch and gradually increasing the audio signal level.

[Action]

The timer outputs a time detection signal at the set time. Further, the audio signal level is compared with a fixed reference level by the level detection circuit, and when it is below the reference level, the level detection circuit outputs a level detection signal. The present invention turns on the power of the audio device by the time detection signal, and outputs the level detection signal based on the level detection signal when the level detection signal is obtained within a fixed time from the time when the time detection signal is obtained. Turn on the switch. Also, if the level detection signal is not obtained within a certain period of time, the audio signal level is once lowered and then the output switch is turned on.
Try to gradually raise the audio signal level.

As a result, according to the present invention, the power is not suddenly turned on when the audio signal level is high, and therefore the user is not uncomfortable.

〔Example〕

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, 1 is a tuner circuit connected to a signal input terminal 2, 3 is a fader circuit composed of a motor 3a and a volume 3b that moves in conjunction with it, 4 is an amplifier circuit, 5 is a speaker, 6 Is a power switch for turning the tuner circuit 1 on or off, 7 is a level detection circuit for detecting the voltage level of the signal 2a input to the signal input terminal 2, and 10 is a timer switch 10 'for setting the time. Timer circuit, 8 is a power switch for turning on or off the power of the amplifier circuit 4, 12 is an output switch for supplying or shutting off the output signal 4a of the amplifier circuit 4 to the speaker 5, and 9 is for turning on the output switch 12.・ Control circuit for controlling the fader circuit 3 as well as for controlling off, 11
Is a power input line.

Here, the operations of the level detection circuit 7, the timer circuit 10 and the control circuit 9 of FIG. 1 will be described.

The level detection circuit 7 receives the signal 2 input to the signal input terminal 2.
When the signal level of "a" falls below a predetermined level, the level detection signal 7a is output.

The timer circuit 10 outputs the time detection signal 10a when the time set by the timer switch 10 'is detected.
The time detection signal 10a turns on the power switches 6 and 8, and as a result, the tuner circuit 1 and the amplifier circuit 4 are turned on.
Power is supplied to.

The control circuit 9 controls the level detection signal 7a and the time detection signal 1
As input 0a, if the time detection signal 10a is a first level detection signal 7a at time t ₄ of time T ₁ which is determined in advance from the time t ₁ that is input is input, the time t
_The output switch control signal 9a is output to 4 to turn on the output switch 12, and the output signal 4a of the amplifier circuit 4 is supplied to the speaker 5. Further, the control circuit 9 controls the time detection signal 1
The first determined from time t _{1 when} 0a is input
Of by the time t ₂ to time T ₁ is passed, when the level detection signal 7a is not input, the second fade control signal until time t ₃ when the expiration of time T ₂ of predetermined from the time t ₂ 9b is output to drive the motor 3a of the fade circuit 3 to gradually reduce the signal level of the signal 3c supplied to the amplifier circuit 4 to zero. Furthermore, the control circuit 9
At this time t ₃ , the output switch control signal 9a is output,
While turning on the output switch 12, and outputs the fade control signal 9b from the time t _3, to time t ₂ without driving the motor 3a of the fader circuit 3 in the opposite direction to the between t _3, supplied to the amplification circuit 4 The signal level of the signal 3c is gradually increased. As a result, the output signal 4a that gradually rises from time t ₃ is supplied to the speaker 5.

Hereinafter, the operation of this embodiment will be described with reference to FIGS. 2 and 3.
It will be described in more detail. In these figures, the same reference numerals as those in FIG. 1 indicate the signal waveforms at the reference numerals in FIG. However, 6, 8 and 12 represent the states of the power switch 6, 8 and the output switch 12 of FIG.

First, the first level detection signal 7a at time T ₁ is the case where the detected will be described with reference to Figure 2.

Timer switch 10 'power switch 6 is turned off (OFF) by the time set by the 8 timer switch 10' when the time detection signal 10a from the timer circuit 10 at time t ₁ set in is output, this It turns on (ON). As a result, power is supplied to the tuner circuit 1 and the amplifier circuit 4. The control circuit 9 receives the first predetermined signal from the time t ₁ when the time detection signal is input.
When the level detection signal 7a is input within the time T ₁ of, the output switch control signal is output.

In FIG. 2, the signal 2 a input from the tuner circuit 1 via the signal input terminal 2 at the time t ₄ within the _first time T ₁ .
Since the level of decrease, the level detecting circuit 7 outputs a level detection signal 7a at the time t _4. As a result, the control circuit 9 outputs an output switch control signal 9a at time t _4. Therefore, the output switch 12 is
It changes from OFF (OFF) to ON (ON) according to the output switch control signal 9a. For this purpose, the output switch 12
The output signal 13 of the amplifier circuit 4 that has passed through the period is supplied to the speaker 5 after the silent section has elapsed from the time t ₄ . The output switch 12 is turned off via the control circuit 9 in response to the time setting by the timer switch 10 '.

That is, in the case of FIG. 2, the output switch 12 is turned on in the silent section of the input signal 2a.

Then, the first level detection signal 7a at time T ₁ is the case where not detected will be described with reference to Figure 3.

As described with reference to FIG. 2 above, when the time detection signal 10a is output from the timer circuit 10 at time t ₁ , the power switches 6 and 8 are turned on in response to this, and the tuner circuit 1 and the amplifier circuit 4 are powered. Is supplied. by the way,
In Figure 3, from time t ₁ to a first time t ₂ of time T ₁ has elapsed predetermined, the level of the input signal 2a not output level detection signal 7a from the level detection circuit 7 in order not to decrease. Therefore, the control circuit 9 controls the time t ₂
From to time t ₃ when the second time T ₂ has elapsed predetermined outputs the fade control signal 9b. As a result, the motor 3a of the fader circuit 3 is driven and the volume 3b is gradually reduced accordingly, so that the level of the output signal 4a of the amplifier circuit 4 gradually decreases to zero.

At time t ₃ , the control circuit 9 outputs the output switch control signal 9 a to turn the output switch 12 from off to on, and at the same time, turns the motor 3 a of the fader circuit 3 in the opposite direction from the time t ₂ to t _3. Fade control signal 9 to drive
Output b. As a result, the output signal 13 of the amplifier circuit 4 passing through the output switch 12 becomes a signal whose level gradually rises from the time t ₃ , and the signal is supplied to the speaker 5.

That is, in the case of FIG. 3, the audio signal level is once reduced to zero and then the output switch 12
When turned on, the audio signal level is gradually increased.

In the above description, the tuner circuit 1 is provided to obtain the input signal 2a, but in the present invention, instead of the tuner circuit 1, another audio device such as a CD player or a television tuner is provided. May be. In addition, the above-mentioned first time T ₁ and second time T
_{The number 2} does not have to be fixed, and may be set freely by the user.

〔The invention's effect〕

According to the present invention, when the audio device is turned on by the wake-up function of the timer, the sound emission from the speaker can be started from a silent period or can be started while fading in from the silent state. This has the effect of not giving the person a feeling of innocence.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIGS. 2 and 3 are waveform diagrams for explaining the operation of FIG. Explanation of symbols 2 ... Signal input terminal, 3 ... Fader circuit, 4 ... Amplification circuit, 5 ... Speaker, 7 ... Level detection circuit, 9 ...
Control circuit, 10 timer circuit, 6, 8 power switch, 12 output switch.

Claims (2)

[Claims] 1. (a) a signal input terminal for inputting an audio signal; (b) an amplifier circuit for amplifying an audio signal supplied through the signal input terminal to drive a speaker; and (c) the amplification. A power supply control device for an audio device, comprising: a power switch that is turned on by a time detection signal to supply power to the circuit; and (d) an output switch for supplying the output signal of the amplifier circuit to the speaker. An output switch turned on by a control signal, and (e) comparing the level of the audio signal supplied via the signal input terminal with a predetermined reference voltage, and the level of the audio signal is equal to or lower than the reference voltage. Sometimes a level detection circuit that outputs the level detection signal, (f) a fader circuit that controls the level of the audio signal supplied to the amplification circuit, and (g) an externally provided A timer circuit that detects a set set time and outputs the time detection signal, and (h) a control circuit that controls the fader circuit and the output switch based on the output signal of the timer circuit and the level detection signal. And (i) the control circuit turns off the output switch according to an output signal of the timer circuit when a set time is set from outside, and the time detection signal is output from the timer circuit. If the level detection signal is output from the level detection circuit before the scheduled first time (T1) has elapsed from the first time (t1), the time (t4) when the level detection signal is output While outputting the output switch control signal for turning on the output switch, (ii) when the level detection signal is not output before the first time (T1) has elapsed, the first time elapsed time (t2)
To a predetermined second time (T2) elapsed time (t3), a fade control signal for decreasing the level of the audio signal supplied to the amplifier circuit is output to the fader circuit, and the second time (T2) is output. ) The output switch control signal that turns on the output switch is output at the elapsed time (t3), and the level of the audio signal supplied to the amplifier circuit is gradually increased from the second time elapsed time (t3). A power supply control device by a timer of an audio device, which has a function of outputting the fade control signal for controlling. 2. The power supply control device by the timer of the audio device according to claim 1, wherein the fader circuit is composed of a motor and a volume that moves in association with the motor.