KR960001316Y1 - Control signal input circuit of tuning apparatus - Google Patents

Abstract

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Description

Control signal input circuit of tuning device

1 is a circuit diagram of a control signal input circuit of a conventional tuning device.

2 is a circuit diagram of a control signal input circuit of a tuning device according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

20: tuning device ANT: aerial

C1-C7: Capacitor L1-L7: Inductor

The present invention relates to a control signal input circuit for introducing a control signal and a power supply voltage in a tuning apparatus of a television receiver, and in particular, of a tuning device capable of efficiently removing a noise signal contained in an input control signal and a power supply voltage. It relates to a control signal input circuit.

A conventional television receiver tuning device polarizes a high frequency signal corresponding to a control signal having a frequency information to be applied from a control device such as a microcomputer and frequency-converts the tuned high frequency signal to generate a frequency converted intermediate frequency signal. do. The tuning device includes an intermediate signal including noise signals, such as beats of impulse components and ripples of high frequency components, by high-frequency component noise signals included in power voltages from the power supply and control signals from the control apparatus. A frequency signal was generated. In order to solve the problem of the tuning device, a conventional tuning device control signal input circuit includes a plurality of capacitors connected between respective input lines and ground potential for inputting the control signals and the power supply voltage. The noise signal of the high frequency component included in the power supply voltage and the control signals is removed by the capacitor. However, the control signal input circuit of the conventional tuning device includes the high frequency component included in the voltage component of the control signals and the power supply voltage by the capacitor. Although the noise signal of the component could be removed, the noise signal of the high frequency component included in the control components and the current component of the power supply voltage could not be removed. The noise signals of the high frequency component are generated in the intermediate frequency signal generated by the tuning device by the noise signal of the high frequency component included in the control signals and the current component of the power supply voltage. The problem of the control signal input circuit of the conventional tuning device will be described in detail with reference to FIG.

Referring to FIG. 1, a control signal input circuit of a conventional tuning device includes a first input line 12 for a power supply voltage connected between a power supply device (not shown) and the tuning device 10, and the tuning device. A second input line 13 for the VHF-L band selection signal, a third input line 14 for the VHF-H band selection signal, and a fourth for the UHF band selection signal, connected between the 10 and a microcomputer (not shown). Between the input line 15, the fifth input line 16 for the channel frequency selection signal, and the sixth input line 17 for the fine frequency selection signal, and the tuning device 10 and the automatic gain controller (not shown). And a seventh input line 18 for gain control signal connected thereto. Seven capacitors C1-C7 are connected between the first to seventh input lines 12-18 and the ground potential GND. The capacitor C1 bypasses the high-frequency noise signal of the power component included in the power supply voltage transmitted from the power supply device (not shown) to the tuning device 10 via the first input line 12, thereby supplying a power supply voltage. Remove the noise signal of the voltage component included in the. The five capacitors C2-C6 are also transferred from the microcomputer (not shown) to the tuning device 10 via the second through sixth input lines 13-17, respectively. VHF-L, VHF-H and UHF selection signal and channel frequency selection by bypassing the H and UHF selection signal, the high frequency noise signal of the voltage component included in the channel frequency selection signal and the fine frequency control signal toward the ground potential (GND). The high frequency noise signal of the voltage component included in the signal and the fine frequency control signal are removed. Similarly, the fraud capacitor C7 also receives a high-frequency noise signal of the voltage component included in the gain control signal transmitted from the automatic gain controller (not shown) to the tuning device 10 via the seventh input line 18. Bypass to the GND) to remove the high-frequency noise signal of the voltage component included in the gain control signal.

As described above, the control signal input circuit of the conventional tuning device removes the high frequency noise signal of the voltage component included in the power supply voltage and the various control signals input to the tuning device using a capacitor, and the high frequency noise signal of the current component is Could not be removed. In addition, the control signal input circuit of the conventional tuning device fails to remove the high frequency noise signal of the current component included in the power supply voltage and various control signals, thereby causing the tuning device to generate an intermediate frequency signal including the high frequency noise signal. I was hugging.

Accordingly, an object of the present invention is to provide a control signal input circuit of a tuning device capable of removing a high frequency component current noise signal and a high frequency component voltage noise signal included in a power supply voltage and various control signals supplied to the tuning device. have.

In order to achieve the above object, the control signal input circuit of the tuning device of the present invention is for transmitting at least one control signal for controlling the power supply voltage from the power supply device and the tuning frequency from the control device to the tuning device. A high frequency component noise signal connected between at least two or more input lines, the at least two or more input lines, and the power supply device and the control device, respectively, and contained in the power supply voltage and voltage components of the one or more control signals. At least two or more voltage noise removing means for removing a high frequency component contained between the at least two input lines and the tuning device respectively and included in the power supply voltage and the current component of the at least one control signal. At least two current noise removing means for removing the noise signal is characterized in that it is provided.

Hereinafter, with reference to the accompanying Figure 2 an embodiment of the present invention will be described in detail.

2, the first input line 22, the first input line 22 and the ground potential (GND) for transmitting a power supply voltage from a power supply device (not shown) to the tuning device 20. And a capacitor C1 connected between each other, and an inductor L1 connected between the tuning device 20 and the first input line 22. The capacitor C1 forms a low pass filter with an output impedance of the power supply device (not shown), and thus the voltage of the high frequency component included in the power supply voltage transmitted from the power supply device to the inductor L1. Remove the noise signal. The inductor L1 forms a low pass filter together with the input impedance of the tuning device 20. The inductor L1 filters the power voltage introduced from the power supply device via the first input line 22 to remove the current noise signal of the high frequency component included in the power supply voltage. As a result, the tuning device 20 is supplied with a power supply voltage from which the voltage noise signal of the high frequency component is removed by the capacitor C1 and the current noise signal of the high frequency component is removed by the inductor L1.

And the control signal input circuit of the tuning device according to an embodiment of the present invention is the second input line 23, VHF-H band selection signal for introducing the VHF-L band selection signal from the microcomputer (not shown) A third input line 24 for inflow, a fourth input line 25 for inputting a UHF band selection signal, a fifth input line 26 for inputting a channel frequency selection signal, and a fine frequency selection signal A sixth input line 27 is further provided. Capacitors C2-C6 are connected between the second to sixth input lines 23 to 27 and the ground potential GND, respectively. The condenser C2 forms a low pass filter together with the output impedance of the microcomputer to be connected to the second input line 23 to form a low pass filter from the microcomputer via the second input line 23 and the inductor L2. The voltage noise signal of the high frequency component included in the VHF-L band selection signal transmitted to the tuning device 20 is removed, and the VHF-L band selection signal from which the voltage noise signal of the high frequency component is removed is transmitted to the inductor L2. . An inductor L2 connected between the second input line 23 and the tuning device 20 forms a low pass filter together with the input impedance of the tuning device 20 to supply the tuning device 20. The high frequency component current noise signal included in the VHF-L band selection signal to be removed is removed. Similarly, the capacitors C3-C6 form a low pass filter together with the output impedance of the microcomputer in the same way as the capacitor C2, and the 3-6 input lines 24-27 and the inductors (3) from the microcomputer. L3-L6) respectively, via the VHF-H band selection signal, the UHF band selection signal, the channel frequency selection signal, and the fine frequency selection signal supplied to the tuning device 20 to the base potential ( Bypass to GND). Inductors L3-L6 connected between the tuning device 20 and the 3-7 input lines 24-27, respectively, are connected to the input impedance of the tuning device 20 in the same manner as the inductor L2. High frequency components included in the VHF-L band selection signal, the UHF band selection signal, the channel frequency selection signal, and the fine frequency control signal introduced through the 3-6 input lines 24-27 by forming a low pass filter together. Remove the current noise signal from. As a result, the VHF-H band selection signal, the UHF band selection signal, and the channel supplied from the microcomputer to the tuning device 20 via the 2-6th input lines 23-27 and the inductors L2-L6. The frequency selection signal and the fine frequency control signal are removed by the capacitors C2-C6, and the high voltage component voltage noise signal is removed by the inductors L2-L6.

In addition, the control signal input circuit of the tuning device according to the embodiment of the present invention has a seventh input line 28 and a seventh input line 28 for introducing a gain control signal from an automatic gain controller (not shown). And a capacitor C7 connected between the ground potential GND and an inductor L7 connected between the tuning device 20 and the seventh input line 28. The capacitor C7 forms a low pass filter together with the output impedance of the automatic gain controller to remove the voltage noise signal of the high frequency component included in the gain control signal transmitted from the automatic controller to the inductor L7. do. The inductor L7 forms a low pass filter together with the input impedance of the tuning device 20. The inductor L7 filters the gain control signal flowing from the automatic gain controller via the seventh input line 28 to remove the current noise signal of the high frequency component included in the gain control signal. As a result, the tuning device 20 is supplied with a gain control signal from which the voltage noise signal of the high frequency component is removed by the capacitor C7 and the current noise signal of the high frequency component is removed by the inductor L7.

As described above, the control signal input circuit of the tuning device of the present invention has a high frequency included in the power voltage and the voltage component of the control signal by the capacitors forming the low pass filter together with the output impedance of the source of the power source and the control signal. The inductors forming the low pass filter together with the input impedance of the tuning device and removing the noise signal of the component provide the advantage of removing the noise signal of the high frequency component included in the current component of the power supply voltage and the control signals. . Due to the above advantages, the control signal input circuit of the tuning device of the present invention provides the tuning device to generate an intermediate frequency signal that does not include noise signals such as bits and ripples of high frequency components.

Claims (3)

At least one control signal for influencing the power supply voltage from the power supply and at least one control signal for controlling the tuning frequency from the control device and transmitting the at least one control signal for transmission to the tuning device Two or more input lines, respectively connected between the at least two or more input lines and the power supply device and the control device to remove noise signals of high frequency components contained in the power supply voltage and voltage components of the at least one control signal. At least two or more voltage noise canceling means and a high frequency component noise signal connected between the at least two input lines and the tuning device, respectively, included in the power component and the current component of the at least one control signal. At least two or more current noise removing means for removing the Control signal input circuit. 2. The control signal input circuit according to claim 1, wherein said voltage noise control means includes a capacitive element for forming a low pass filter together with output impedances of said power supply device and said control device. 2. The control signal input circuit according to claim 1, wherein the current noise removing means includes an inductive element for forming a low pass filter together with the input impedance of the tuning device.