JPS5823030B2 - Attached equipment for television receivers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to television receiver accessory devices such as television boosters and converters, and particularly to devices to which power is automatically supplied in synchronization with the power switch of the television receiver.

Conventionally, most devices attached to television receivers, such as television boosters and converters, do not have power switches and are always powered on.

However, this is not preferable from the viewpoint of energy saving, and especially in the case where a battery is used as a power source, the battery consumption becomes extremely rapid.

For this reason, recently, power switches have been installed, but since they are installed independently of the television receiver, the switches must be turned on and off each time, making the operation complicated.

For this reason, the power was often left on at all times.

The present invention has been made in view of the above points, and an object of the present invention is to provide an accessory device for a television receiver that is automatically supplied with power in synchronization with a switch on the television receiver. be.

Another object of the present invention is to provide an accessory device for a television receiver that is non-contact and has a switching circuit that consumes less power.

The accessory device for the television receiver according to the present invention uses a simple antenna to transmit the horizontal deflection signal output from the flyback transformer of the television receiver or the electron beam horizontally scanning the screen (hereinafter, these are collectively referred to as horizontal signals). This is picked up and rectified, and during the period when this rectified signal exists, the switching circuit is turned on or off to receive power supply voltage.

Therefore, according to the present invention, the power supply voltage is supplied only when necessary without any complicated switching operations, thereby preventing unnecessary power consumption.

In addition, the switching circuit itself can be designed so that the power supply is completely disconnected when it is off, and even when it is on, the power consumption is extremely low compared to the power consumption of all attached equipment.
It consumes very little power, making it ideal for circuits powered by dry batteries, etc.

Furthermore, since the switching circuit is a non-contact type, failures can be reduced.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a television booster, and FIG. 2 is a diagram showing the television booster mounted on a television receiver.

In FIG. 1, the antenna 11 is for extracting the horizontal deflection signal generated from the flyback transformer of the television receiver by electromagnetic induction, and is a very simple antenna using, for example, a vinyl-coated conductor of an appropriate length. It is.

As shown in FIG. 2, the antenna 11 is taken out from the booth case 24 in which the two power switch circuits of the present invention are incorporated and placed near the flyback transformer 26 of the television receiver 25.

When the power switch of the television receiver 25 is turned on, a horizontal deflection signal is generated from the flyback transformer 26, so that this horizontal deflection voltage is induced in the antenna 11.

This voltage is led to a rectifier circuit 13 through a resistor 12 and rectified.

The rectifier circuit 13 is constituted by, for example, a well-known voltage doubler rectifier circuit comprising capacitive elements 14, 15 and diodes 16, 17.

When such a voltage doubler rectifier circuit is used, switching sensitivity can be increased, and at the same time, it can also function as a protection circuit against discharge.

That is, when a positive unused voltage is applied, this voltage is applied to the capacitive element 14, the diode 17, and the capacitive element.

It is grounded by 15.

Further, when a negative discharge voltage is applied, the capacitive element 14 and the diode 16 are similarly grounded.

The resistor 12 is provided to limit the current due to this discharge voltage.

The output of the rectifier circuit 13 is connected to the transistor 1 through the resistor 18.
Applied to the base of 9.

Here, the resistor 18 is intended to make the transistor 19 side high impedance so that current due to discharge does not flow into the transistor 19.

The emitter of the transistor 19 is grounded, and the collector is connected to the base of the transistor 21 via a resistor 20.

This transistor 21 is connected in series between a power supply 22 and a power supply terminal of the booster body 23, and is controlled to open or close by the output of the rectifier circuit, and supplies the power supply voltage 22 to the booster body.

That is, when the transistor 19 becomes conductive due to the output of the rectifier circuit, the transistor 21 also becomes conductive, and the power supply 2
2 and the power terminal of the booster body 23 are connected, and voltage is applied to the booster body 23.

Here, the resistor 20 provided between the transistors 19 and 21 is used to prevent the voltage applied to the capacitive element 15 from increasing and the current flowing through the transistor 19 to increase, and to prevent the collector current of the transistor 19 from increasing. It is set to be 1/the current amplification factor of the current flowing through the booster main body 23.

When the power switch of the television receiver 25 is turned off, the inductive load from the flyback transformer 26 disappears, the voltage of the capacitive element 15 gradually decreases, and the voltage of the transistor 19.
21 are both in the cut-off state.

Therefore, in this case, the power supply terminals of the power supply 22 and the booster body 23 are cut off, and the booster body 23 is not supplied with power supply voltage.

As described above, according to the present invention, the power source is automatically connected to the booster in synchronization with the power switch of the television receiver, so that no complicated switching operation is required.

Therefore, it is possible to prevent unnecessary power consumption of the booster due to forgetting to turn off the switch, etc., and it is most suitable for a circuit that uses a dry battery as a power source.

Furthermore, according to the present invention, the switching circuit itself consumes no power because the power supply is completely disconnected in the off state, and even in the on state, the power consumption is only 1 times the current amplification factor of the switching transistor compared to the power consumption of the entire booster. Its power consumption is very low.

Therefore, the power consumption of the switching circuit itself is hardly a problem.

Furthermore, since the switching circuit is of a non-contact type, failures such as contact failures are eliminated and reliability is improved compared to conventional ones using mechanical switches.

Furthermore, the antenna is very easy to install and handle because it is sufficient to simply hang a conductive wire from the rear surface of the cabinet of the television receiver, and there is no need to make any modifications to the television receiver.

In the above embodiment, the present invention is applied to a TV booster, but it can be applied to external equipment such as a converter in exactly the same way.

Further, in the embodiment, the horizontal deflection voltage from the flyback transformer is induced as a switch signal, but the horizontal scanning electron beam of the art dealer may be similarly induced with an antenna as the switch signal.

In this case, the antenna must be placed near the screen.

Further, although a voltage doubler rectifier circuit is used as the rectifier circuit, an n-fold voltage rectifier circuit may be used.

If there is no possibility of a discharge phenomenon occurring, a simple rectifier circuit may be used.

In addition, when using the circuit of the present invention in a place where other induced voltages other than the horizontal signal induced voltage from the flyback transformer are strong, a predetermined frequency filter is connected to the antenna 11 and the voltage doubler rectifier to remove such electrons. If inserted between the circuits 13, malfunctions can be prevented.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment in which the present invention is applied to a television booster, and FIG. 2 is a diagram showing the booster according to the above embodiment mounted on a television receiver. 11...Antenna, 12,18.20...
...Resistance, 13... Voltage doubler rectifier circuit, 14.1
5... Capacitive element, 16, 17... Diode, 19, 21... Switching transistor, 22... Power supply, 23... Booster Main body, 24... Booster case, 25...
...Television receiver, 26...Flyback transformer.

Claims (1)

[Claims] 1. A means for extracting a horizontal signal from a television receiver by electromagnetic induction, a means for rectifying the horizontal signal obtained by this means, and a switch that is in an on or off state during the period when this rectified output exists. An accessory device for a television receiver, comprising a switching circuit held in the television receiver. 2. The accessory device for a television receiver as claimed in claim 1, wherein the means for extracting the horizontal signal by electromagnetic induction consists of a conductor of a suitable length and is placed near the television receiver cabinet. 3. The accessory device for a television receiver according to claim 1, wherein the rectifier comprises a voltage doubler rectifier circuit. 4. The accessory device for a television receiver according to claim 1, wherein the rectifying means comprises a filter for removing unnecessary induced voltage from the antenna output and a circuit for rectifying the filter output. 5 The switching circuit includes a resistor connected to one electrode of this transistor to control the current flowing through the first transistor that is turned on by the rectified output, and a resistor that is connected to the other end of this resistor and is turned on in synchronization with the first transistor. or a second transistor kept in an off state.