JPH0795854B2 - Degaussing circuit - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a degaussing circuit that can be used in a television receiver.

2. Description of the Related Art Recently, a television receiver with a turntable has been put into practical use, but when rotated, the electron beam of a color cathode ray tube is affected by the effect of geomagnetism, resulting in color unevenness on the screen. ing.

For example, as shown in FIG. 2, in the conventional degaussing circuit,
A television receiver is installed at an arbitrary place, and when the main power switch 5 is turned on, the degaussing element 7a is operated to pass a current through the degaussing coil 8 to perform degaussing. Next, when the turntable of the television receiver is rotated, the demagnetization switch
The degaussing element 7b is operated by pressing 17, and a current is passed through the degaussing coil 8 for degaussing. Reference numeral 6 denotes an opening / closing circuit controlled by a remote controller, which is turned on when the transistor 16 is turned on to perform the degaussing operation in the same manner as when the main power switch 5 is turned on.

However, this degaussing circuit is not practical in this degaussing circuit because the degaussing switch 17 must be pushed each time the rotation of the rotary table is to be controlled by remote control.

The present invention solves such a problem and provides a degaussing circuit which can be operated by remote control.

Means for Solving the Problems In the degaussing circuit of the present invention, the degaussing operation is performed by controlling the relay and the pulse delay circuit by remote control.

Action In the degaussing circuit of the present invention, when the power is turned on by the main power switch or the remote control, on the television receiver side,
At this time, the power is generated for the first time to turn on the relay, operate the degaussing element, and supply a current to the degaussing coil. Next, when the turntable is rotated, pressing the degaussing switch on the remote control transmitter side causes the microcomputer on the receiver side to output a single-shot pulse, which is passed through the pulse delay circuit to enable degaussing operation. The pulse of time is made, the relay is turned on by the pulse, and the current is passed through the degaussing coil.

Example Hereinafter, a degaussing circuit according to an example of the present invention will be described with reference to the drawings. As shown in FIG. 1, when the main power switch 5 is pressed and when the power is turned on by the remote controller (at this time, the voltage of the transistor 16 becomes high level and the first switching means 6 is turned on). Is the time required for degaussing (2-
Pulse for 3 seconds, the transistor 15 is turned on, the second switching means 9 is turned on, the degaussing element 7a operates, and a current flows through the degaussing coil 8. Next, when the turntable is rotated, pressing the demagnetization switch on the remote control transmitter side causes a single pulse to be generated from the microcomputer 10. The pulse is delayed by the pulse delay circuit (monomulti, etc.) 11, the resistor 12, the capacitor 13 According to the time constant of, a pulse for 2 to 3 seconds is generated, the transistor 15 is turned on, the second switching means 9 is turned on, the degaussing element 7a operates, and a current flows through the degaussing coil 8.

As described above, according to the degaussing circuit of the present invention, the degaussing function can be operated by remote control. Further, as compared with the prior art, one degaussing element and the degaussing switch can be eliminated, and even if a relay and a pulse delay circuit are added, the cost is advantageous.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a degaussing circuit according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of a degaussing circuit of a conventional example. 1 ... AC cord, 2 ... Fuse resistance, 3 ... Fuse, 4 ... Line filter, 5 ... Main power switch, 6
...... First switching means, 7a, 7b …… Degaussing element, 8
... Degaussing coil, 9 ... second switching means, 10 ...
… Microcomputer, 11 …… Pulse delay circuit, 12,13 …… Resistors, capacitors that determine the pulse delay time constant, 14 …… Arbitrary power supply for charging section, 15 …… Transistor, 16 …… Power-on voltage terminal for remote control , 17 …… Degaussing switch.

Claims (1)

[Claims] 1. A microcomputer for decoding a received remote control signal from a remote control device to generate a control signal for controlling various functions of a television receiver, and a power supply for the television receiver. On the other hand, a main power switch for connecting and disconnecting an AC power source is inserted and arranged in series, and an AC conductive path to the power source of the television receiver is controlled to be opened and closed by a remote control signal from the remote control device. Switching means, a second switching means connected in series with the degaussing coil and the degaussing element, and connected in parallel with the power source of the television receiver, and connected to an opening / closing control terminal of the second switching means. When it is necessary to degauss due to the starting voltage when the power of the television receiver is started. Differentiating circuit for generating a pulse of the degaussing pulse, and a pulse generated under the control of the microcomputer when a degaussing remote control signal is received from the remote control device is changed into a pulse of a time required for degaussing operation, and the second switching A pulse delay circuit for supplying to the opening / closing control terminal of the means, after the main power switch is turned on, the first switching means is controlled to be closed by the remote control signal, and the power source of the television receiver is started. When I did
The second switching means is closed and controlled by a pulse obtained by differentiating the starting voltage by the differentiating circuit to supply a degaussing current to the degaussing coil for a predetermined time, and degaussing is required during operation of the television receiver. In this case, the pulse generated by the degaussing remote control signal from the remote control device is converted into a predetermined width by the pulse delay circuit, and the second switching means is closed to the degaussing coil. A degaussing circuit characterized in that a degaussing current is supplied for a predetermined time.