JP4347444B2 - Power switchgear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power switch for controlling power supply and stop to an electric device, and more particularly to a device for controlling power supply and stop in connection with power supply and stop to another electric device.
[0002]
[Prior art]
Conventionally, there are a television receiver 2 and an amplifier built-in indoor antenna 4 as shown in FIG. The amplifier built-in indoor antenna 4 amplifies the television broadcast signal received by the antenna 6 by the amplifier 8 and supplies the output of the amplifier 8 to the television receiver 2 through the filter 10 and the output terminal 12. . The television receiver 2 is driven by a DC voltage obtained by rectifying and smoothing a commercial AC voltage, and this DC voltage is supplied and stopped by opening and closing a power switch (not shown). The indoor antenna 4 with a built-in amplifier is driven by a DC voltage from an adapter or battery that rectifies and smoothes commercial AC voltage, and this DC voltage is supplied and stopped by turning on or off the power on / off circuit 14. .
[0003]
[Problems to be solved by the invention]
In such a television receiver 2 and the indoor antenna 4 with a built-in amplifier, power is supplied to each other independently of each other. Therefore, when viewing a television broadcast with the television receiver 2, the power switch of the television receiver 2 must be closed and the power on / off circuit 14 of the amplifier built-in indoor antenna 4 must be operated. The operation was troublesome. Since these two operations are troublesome, in the case where the amplifier built-in indoor antenna 4 is supplied with voltage by an adapter, power supply to the amplifier built-in indoor antenna 4 is often left and wasteful power consumption There were many.
[0004]
The present invention provides a power switchgear that improves operability and saves power by enabling supply or stop of power to another electrical device in response to supply or stop of power to one electrical device. The purpose is to do.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the power switchgear according to the present invention generates a magnetic flux inside when power is supplied, and the magnetic flux disappears when power supply is stopped . A power switching device that is disposed in the vicinity and is attached to a second electric device that is used together with the first electric device, the magnetic flux detecting means for detecting a magnetic flux change in the first electric device, and the magnetic flux detecting means A power switch that changes a power supply state to the second electrical device when a magnetic flux change is detected. The magnetic flux detection means induces voltages of different polarities based on a magnetic flux change caused by power supply to the first device and a magnetic flux change caused by power supply stop to the first device. A first comparator that produces an output when the polarity of the voltage induced in the coil represents the power supply, and an output when the polarity of the voltage induced in the coil represents the power supply stop. When the output of the generated second comparator and the first and second comparators are supplied, and when the output of the first comparator is supplied, the power switch is turned on, and the output of the second comparator is And switching means for turning off the power switch when supplied.
[0006]
In this power switchgear, when power is supplied to the first electrical device, magnetic flux is generated in the first electrical device. The generation of the magnetic flux is detected by the magnetic flux detection means, and the power switch supplies or stops power to the second electric device. When the supply of power to the first electrical device is stopped, the magnetic flux generated so far disappears. The disappearance of the magnetic flux is detected by the magnetic flux detection circuit, and the power switch stops or supplies power to the second electric device. Linking power supply and stop of a plurality of electric devices has been performed so far. However, this requires wiring between a plurality of electrical devices. According to the present invention, the power supply and stop of the first and second electric devices are interlocked, but since the magnetic flux detection means is used, no wiring is required between the first and second electric devices. It is.
[0007]
As the first electric device, a device having a CRT can be used. The magnetic flux change occurs based on the supply or stop of power to the device. Generally, since a deflection coil is provided in the CRT, the deflection coil generates a large magnetic flux from the non-generated state by supplying power, and the largely generated magnetic flux disappears by stopping the power supply. That is, since a large magnetic flux change is caused by supplying and stopping the power supply, detection can be easily performed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The power source switching apparatus according to the embodiment of the present invention is provided in a second electric device, for example, the indoor antenna 20 with a built-in amplifier. The amplifier built-in indoor antenna 20 is disposed in the vicinity of a first electric device used together with the amplifier built-in indoor antenna 20, for example, a television receiver 22. The television receiver 22 has a CRT. When power is supplied to the television receiver 22, a deflection coil of the CRT generates a large magnetic flux. When the supply of power to the television receiver 22 is stopped, the large magnetic flux generated by the deflection coil of the CRT until now disappears. That is, the magnetic flux change is large.
[0011]
The amplifier built-in indoor antenna 20 includes an indoor antenna 24, an amplifier 26, a filter 28, and an output terminal 30, similarly to the above-described conventional antenna. For example, at least one or both of UHF and VHF television broadcast signals received by the indoor antenna 24 are amplified by the amplifier 26, and unnecessary components of the output signal of the amplifier 26 are removed by the filter 28. 30 to an antenna input terminal (not shown) of the television receiver 22.
[0012]
The amplifier built-in indoor antenna 20 has a magnetic flux detection circuit 32. The magnetic flux detection circuit 32 is a passive element, for example, a pattern coil formed by etching or the like on a printed board (not shown). Since the magnetic flux detection circuit 32 is disposed in the vicinity of the television receiver 22 as described above, the magnetic flux detection circuit 32 generates a voltage in response to the generation or disappearance of the magnetic flux of the deflection coil of the CRT. To do. The generated voltage is, for example, a positive voltage when the magnetic flux is generated, and a negative voltage when the magnetic flux is lost.
[0013]
This voltage is supplied to the magnetic flux presence / absence determination ON / OFF circuit 34. The magnetic flux presence / absence determination ON / OFF circuit 34 has a comparator 36, which compares the voltage supplied from the magnetic flux detection circuit 32 and the reference voltage supplied from the reference voltage generation circuit 38, for example, a positive reference. Compare the voltage. The positive reference voltage is higher than the voltage generated by the magnetic flux detection circuit 32 when the magnetic flux detection circuit 32 detects the magnetic flux generated by the deflection coil of the CRT by supplying power to the television receiver 22. It is set to a low voltage. When the voltage from the magnetic flux detection circuit 32 is higher than the positive reference voltage, the comparator 36 generates, for example, an H level output signal.
[0014]
The magnetic flux presence / absence determination ON / OFF circuit 34 further includes a comparator 40, which also compares the voltage from the magnetic flux detection circuit 32 with a reference voltage from the reference voltage generation circuit 42, for example, a negative reference voltage. To do. The negative reference voltage is set to be larger than the negative voltage generated by the magnetic flux detection circuit 32 in accordance with the disappearance of the magnetic flux when the voltage supply to the television receiver 22 is stopped. The comparator 40 generates, for example, an H level output signal when the voltage from the magnetic flux detection circuit 32 is lower than the negative reference voltage. Note that one value, for example, 0 V, may be used by combining the positive and negative reference voltages.
[0015]
The output signals of the comparators 36 and 40 are supplied to switching means, for example, the set terminal S and reset terminal R of the RS flip-flop circuit 44, respectively. When the output signal of the comparator 36 is supplied to the set terminal S, the Q output terminal of the RS flip-flop circuit 44 becomes H level. Further, when the output signal of the comparator 40 is supplied to the reset terminal R, the Q terminal becomes L level.
[0016]
The Q terminal of the RS flip-flop circuit 44 is connected to a control terminal of a power switch, for example, a semiconductor switching element 46 such as a bipolar transistor or FET. The conductive path of the semiconductor switching element 46 is connected, for example, between a power supply terminal 48 generating a DC voltage obtained by rectifying and smoothing a commercial AC voltage and a power supply terminal 50 of the amplifier 26, and is controlled. It is closed during the period when the H level signal is supplied to the terminal. Therefore, the comparator 36 generates an output signal, the Q terminal of the RS flip-flop circuit 44 becomes H level, the comparator 40 generates the output signal, and the Q terminal of the RS flip-flop circuit 44 is at L level. It is closed until it becomes.
[0017]
Accordingly, when a power switch (not shown) is operated to supply power to the television receiver 22, the deflection coil of the CRT generates a magnetic flux, which is generated by the magnetic flux detection circuit 32. The comparator 36 generates an output, the Q terminal of the RS flip-flop circuit 44 generates an H level output, the semiconductor switching element 46 is closed, and a DC voltage is supplied to the amplifier 26. 26 operates.
[0018]
When the supply of the DC voltage to the television receiver 22 is stopped by operating the power switch to stop viewing on the television receiver 22, the magnetic flux generated by the CRT deflection coil disappears. The disappearance of the magnetic flux is detected by the magnetic flux detection circuit 32, the comparator 40 generates an output signal, the Q terminal of the RS flip-flop circuit 44 becomes L level, the semiconductor switching element 46 is opened, and the amplifier 26 is connected to the amplifier 26. The supply of DC voltage is stopped and the amplifier 26 stops operating.
[0019]
In other words, the amplifier built-in indoor antenna 20 starts operating in conjunction with the power supply to the television receiver 22, and the amplifier built-in indoor antenna 20 operates in conjunction with the stop of the power supply to the television receiver 22. To stop. To start and stop the operation of the amplifier built-in indoor antenna 20, no switch operation is required on the amplifier built-in indoor antenna 20 side. In addition, since the supply and stop of the power supply of the amplifier built-in indoor antenna 20 are controlled by detecting the magnetic flux generated by the television receiver 22, the space between the television receiver 22 and the amplifier built-in indoor antenna 20 is controlled. No special wiring is required, and it is not necessary to change the circuit of the television receiver 22 in order to be interlocked.
[0020]
Since the magnetic flux detection circuit 32 is a pattern coil as described above, it does not consume power. The magnetic flux presence / absence determination ON / OFF circuit 34 must always be supplied with electric power in order to open and close the semiconductor switching element 46. Become. Also, in the magnetic flux presence / absence determination ON / OFF circuit 34, power is consumed only by the comparators 36 and 40 and the RS flip-flop circuit 44, and only very little power is consumed, thereby saving power. Can be planned. The magnetic flux detection circuit 32, the comparators 36 and 40, and the RS flip-flop circuit 44 constitute magnetic flux detection means.
[0021]
The indoor antenna 20 with a built-in amplifier is provided with a manual ON / OFF circuit 52. The manual ON / OFF circuit 52 has, for example, a power switch (not shown). When this power switch is closed, an H level output signal is supplied to the S terminal of the RS flip-flop circuit 44, and the power switch When the circuit is opened, an H-level output signal is supplied to the R terminal of the RS flip-flop circuit 44. Therefore, the supply of voltage to the amplifier 26 can be started and stopped also by operating the power switch of the manual ON / OFF circuit 52.
[0022]
The magnetic flux presence / absence determination ON / OFF circuit 34 also includes a display circuit 54 including a plurality of, for example, two LEDs. In the mode in which the operation of the amplifier built-in indoor antenna 20 is started and stopped in conjunction with the start and stop of the supply of power to the television receiver 22, the display circuit 54 lights one LED. In the mode in which the operation of the indoor antenna 20 with a built-in amplifier is started and stopped by operating the power switch of the manual ON / OFF circuit 52, the display circuit 54 lights two LEDs. Based on the difference in the number of lighted LEDs, it can be displayed in which mode the amplifier built-in indoor antenna 20 is operating.
[0023]
The power switching device of the above embodiment is provided in an indoor antenna with a built-in amplifier used together with a television receiver. However, the indoor booster, the CATV in-home compensation booster, the active AV selector, the RF switch, and the VTR booster are provided. It can also be used for electric equipment used together with a television receiver such as a home game machine. Alternatively, in a CRT type monitor of a personal computer and a printer, the power supply switching device can be provided in the printer. Moreover, not only the device used with the television receiver, but also an electric device that leaks some magnetic flux to the outside even when power is supplied, and an electric device that is arranged near the device and used together. It can also be used in combination, for example, a combination of a stereo main amplifier and a tuner or CD player or MD player. In this case, this power switching device may be provided in any device. In addition, a plurality of devices provided with the power switching device can be provided.
[0024]
In the power switchgear according to the above embodiment, the semiconductor switching element is used as the power switch, but a relay circuit can also be used. Further, a battery may be connected to the power terminal 48 and used as a power source.
[0025]
【The invention's effect】
As described above, according to the present invention, when the magnetic flux detection means detects the magnetic flux generated by the supply of power to the first electric device, the power switch indicates the supply state of power to the second electric device. Since the control is performed, it is not necessary to manually control the power supply to the second electric device. In addition, since it is not necessary to always supply power to the second electrical device, power saving can be achieved. Moreover, it is not necessary to wire between the first and second electric devices in order to control the power supply state to the second electric device. Further, if the first electric device is provided with a CRT, the magnetic flux change is large, and the magnetic flux can be easily detected by the magnetic flux detection means. In addition, since the magnetic flux detection means includes a coil that does not consume power and a comparison means that compares the voltage induced in the coil and a reference voltage, the supply of power to the second electrical device is controlled. For this reason, only the comparison means needs to be supplied with electric power at all times, and power saving can be achieved.
[Brief description of the drawings]
FIG. 1 is a block diagram of a television receiver equipped with a power switch according to the present invention and an indoor antenna with a built-in amplifier.
FIG. 2 is a block diagram of a conventional television receiver and an indoor antenna with a built-in amplifier.
[Explanation of symbols]
20 Indoor antenna with built-in amplifier (second electrical equipment)
22 Television receiver (first electrical device)
32 Magnetic flux detection circuit (magnetic flux detection means)
36 40 comparator (magnetic flux detection means)
46 Semiconductor switching element (power switch)

Claims (2)

When power supply is performed, magnetic flux is generated inside, and when power supply is stopped, the second magnetic flux is disposed in the vicinity of the first electric device where the magnetic flux disappears and is used together with the first electric device. A power switchgear attached to an electrical device,
Magnetic flux detection means for detecting magnetic flux changes in the first electrical device;
A power switch that changes a power supply state to the second electrical device when the magnetic flux detection means detects a magnetic flux change;
The magnetic flux detection means comprises:
A coil in which a voltage of a different polarity is induced based on a magnetic flux change caused by power supply to the first device and a magnetic flux change caused by power supply stop to the first device;
A first comparator that produces an output when the polarity of the voltage induced in the coil represents the power supply;
A second comparator that produces an output when the polarity of the voltage induced in the coil represents the power supply outage;
When the outputs of the first and second comparators are supplied and the output of the first comparator is supplied, the power switch is turned on, and when the output of the second comparator is supplied, the power switch Switching means for turning off
Power switchgear provided .   The power switchgear according to claim 1, wherein the first electric device is a device provided with a CRT, and the magnetic flux change is generated when the power is supplied to or stopped from the device.

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