KR19990031930A - Power supply protection device of low noise frequency converter - Google Patents

Abstract

The present disclosure relates to a power supply protection device of a low noise frequency converter for receiving a satellite broadcast signal for receiving a full band satellite broadcast signal.

The power supply protection device of the disclosed low noise frequency converter (LNB) comprises: voltage interrupting means for controlling an input voltage of a predetermined level according to an external interruption control signal; Voltage selection signal generating means for generating a polarization voltage selection signal for selecting a voltage corresponding to frequency polarization by a polarization mode control signal according to satellite broadcasting channel selection; Polarization voltage generating means for stabilizing a voltage of a predetermined level obtained by the voltage interrupting means to first and second polarization operating voltages suitable for frequency polarization, and selecting one polarization voltage by the polarization voltage selection signal and providing it to the LNB; It includes a polarization voltage interruption means for detecting the level of the voltage provided to the LNB to interrupt the voltage interruption means in the event of an abnormality to cut off the voltage of a predetermined level, so that the LNB installed in the outdoor parabolic antenna is downlinked from the satellite It is possible to easily receive left and postal waves, and also to prevent breakage of the power supply stage of the LNB terminal power supply and the set-tub box due to leakage.

Description

Power supply protection device for low noise frequency converter.

The present invention relates to a low noise frequency converter (LNB: abbreviated as "LNB") for satellite broadcasting reception. More particularly, the present invention relates to a power source for frequency polarization by left and postal waves according to a plurality of satellite broadcasting channels. LNB power supply protection device to easily receive down-linked left and postal waves from satellites and prevent burnout of LNB's power terminal and set top box by leakage It is about.

In general, the satellite broadcasting method is a European communication satellite (ECS) or Direct Broadcasting Satellite (DBS) for the frequency spectrum. Each frequency band has an ECS of 10.95 to 11.7 GHz and a DBS of 11.7 to 12.7 GHz.

Since only one satellite broadcast can be received by one LNB unit, two LNB units are required to receive satellite broadcasts of the ECS band and DBS band.

In the satellite broadcasting having the above-described broadcasting method, in order to prevent interference of satellite broadcasting waves of a plurality of channels, for example, the satellite broadcasting waves of the odd channel are the left-hand wave propagation, and the satellite broadcasting waves of the excellent channel are the postal wave propagation. The polarization plane of the broadcast wave is alternately set for each channel left and right.

Therefore, in a satellite broadcasting receiver that selectively receives a plurality of broadcast waves in such satellite broadcasting, that is, in a set top box, LHCP and postal wave (RHCP) propagation are one system. The parabolic antenna is provided with a polarization converting device for changing the polarization plane of the received radio wave so as to be able to receive it.

In addition, the polarization converter is provided at a center point of the parabolic antenna installed outdoors to a channel for receiving a feeder for receiving the satellite broadcast wave reflected therefrom, the left polarization wave and the postal wave of the received satellite broadcast wave. Polarizer that separates and outputs the signal, and converts the radio wave received in the approximately 12 GHz band into the intermediate frequency signal of the approximately 1 GHz band and provides the satellite broadcasting tuner of the settub box installed indoors through a coaxial cable. It includes a low noise LNB.

However, the downlink signal from the satellite uses a left polarization wave and a postal wave in order to effectively utilize the allocated frequency. In the LNB of the polarization conversion device receiving the signal, 14 V ± 1 V for the postal file and 18 V ± 1 V for the left file It acts as a power source.

As such, the apparatus for receiving the downlink signal from the satellite and providing it to the satellite broadcast tuner of the settub box includes the apparatus as shown in FIG. 1.

The apparatus shown in FIG. 1 will be described as an example of a conventional LNB for satellite broadcasting reception.

The LNB for receiving a satellite broadcast includes a low noise amplification unit 100 for wideband amplifying and outputting a high frequency satellite broadcast signal (10.95-12.7 GHz) inputted by converting a polarization plane in a polarity controller, and power amplifying the amplified satellite broadcast signal. The power divider 101 to separate and output the ECS band signal and the DBS band signal, and the first and second band pass filter units 102 and 103 for band-filtering and outputting the separated ECS band and DBS band signals, respectively. And a band selection switch 111 for selecting and providing a power supply voltage Vcc inputted to generate a local oscillation frequency according to the broadcasting method, and a local oscillation of 10 GHz by the selected power supply voltage Vcc. A first local oscillator 106 for generating a frequency, a second local oscillator 107 for generating a local oscillation frequency of 10.75 GHz by the selected voltage voltage Vcc, and the satellite broadcast signal in the filtered ECS band Local oscillation week with 10GHz A first mixing unit 104 which extracts an intermediate frequency for the satellite broadcasting signal of the ECS band by mixing the numbers; and a satellite broadcasting of the DBS band by mixing the filtered satellite broadcasting signal of the DBS band and a local oscillation frequency of 10.75 GHz. A second mixing unit 105 for extracting an intermediate frequency for a signal, first and second low pass filters 108 and 109 for low pass filtering each extracted intermediate frequency and outputting the same through a diode, and the low range It consists of an intermediate frequency amplifier 110 for amplifying the filtered intermediate frequency to a sufficient size and providing it to the satellite broadcasting tuner (not shown in the figure) of the set-tub box provided indoors.

In the conventional LNB for receiving satellites configured as described above, as is well known, a full-band (10.95-12.7 GHz) satellite broadcast signal transmitted from a satellite is amplified by a low noise amplifier 100 designed for wideband, and then a power divider ( 101 is provided.

The power divider 101 amplifies the input full-band satellite broadcast signal and separates the amplified signal into a signal of the ECS band and a signal of the DBS band, respectively.

The satellite broadcast signal of the separated ECS band is filtered by the first bandpass filter 102 and provided to the first mixer 104.

The satellite broadcast signal of the DBS band is filtered by the second band pass filter 103 and provided to the second mixer 105.

The first mixing unit 104 mixes the satellite broadcasting signal of the 10.95-11.7 GHz ECS band input from the first bandpass filter unit 102 and the 10 GHz oscillation frequency generated by the first local oscillating unit 106 to generate the first mixing band. 1 The intermediate frequency is extracted.

In addition, the second mixing unit 105 adjusts the satellite broadcasting signal of the DBS band of 11.7-12.7 GHz input from the second band pass filter 103 and the 10.75 GHz oscillation frequency generated by the second local oscillator 107. By mixing, the second intermediate frequency is extracted.

After the extracted first and second intermediate frequency signals are low-pass filtered by the first and second low pass filters 108 and 109, they are amplified to a sufficient size through the diode and through the common intermediate frequency amplifier 110. It is provided to the satellite receiver in the room, that is, the satellite tuner of the settub box.

At this time, the selection of the satellite broadcasting signal of the ECS band and the satellite broadcasting signal of the DBS band includes the first local oscillator 106 and the second local oscillator 107 having the oscillating power supply voltage Vcc through the band selection switch 111. This is achieved by selectively supplying to.

However, the above-described conventional LNB for receiving satellite broadcasting is typically installed in a parabola antenna and operated by a power supplied from a power supply device, so that an intermediate frequency signal for a full band satellite broadcasting signal is provided indoors through a coaxial cable. It is provided to the satellite broadcasting tuner of the settub box, it can be seen that such LNB or power supply is exposed to rain, snow, etc. due to the relationship installed in the external parabolic antenna.

Therefore, when the power supply of the LNB is short-circuited due to rain or snow leakage, satellite broadcasting reception is not possible and the elements of the LNB, in particular, the elements of the power supply terminal are damaged, and coaxial with the LNB. The power terminal of the set-tub box connected through the cable also has a problem that the parts are broken by short circuit.

As a result, in the conventional technology, when an abnormality occurs in the LNB, it is difficult for the viewer to check in which part the failure occurs, which necessitates the hassle of requesting the service.

Therefore, a device that protects the power supply terminal of the LNB to be able to receive broadband satellite broadcasting equivalent to or higher than the conventional one without the component damage of the power supply terminal or the satellite broadcast reception impossible state due to leakage.

Accordingly, the present invention excludes the component damage and the satellite broadcast reception impossible state due to the leakage of the power supply device of the LNB in the above-described prior art, and, in one aspect of the present invention, receives a broadband satellite broadcast signal. It is an object of the present invention to provide a power supply protection device of the LNB to automatically cut off and protect the LNB power when an abnormality occurs in the power supply terminal due to leakage in the state.

In another aspect of the present invention, it is an object of the present invention to accurately determine a left-wing wave and a post-wave transmitted by being downlinked from a satellite, and supplying a corresponding power to the LNB to accurately receive a satellite broadcast signal without error.

As another aspect of the present invention, an object of the present invention is to automatically cut off the power supply of the LNB when an error occurs in the LNB in the state of receiving the satellite broadcast signal of the wideband, and to display the LNB error state on the screen.

Another aspect of the present invention is to provide a stable power supply to the LNB.

1 is a block diagram of a conventional low noise frequency converter (LNB) for satellite broadcasting reception;

2 is a circuit diagram showing an embodiment provided in the description of a power supply protection device of a low noise frequency converter (LNB) for satellite broadcasting reception according to the present invention;

3 is a circuit diagram showing another embodiment provided in the description of the power supply protection device of the low noise frequency converter for satellite broadcasting reception of the present invention.

<Description of Symbols for Main Parts of Drawings>

200: voltage interrupter 201: polarization voltage generator

202: voltage selection signal generator 203: polarization voltage interruption

207: microprocessor 208: font ROM

209: on-screen image generating unit 210: image mixing unit

Power supply protection device of the LNB according to an aspect of the present invention for achieving the above object, the power supply of a low noise frequency converter (LNB) for supplying an operating voltage to the low noise frequency converter for receiving a full-band satellite broadcast signal An apparatus comprising: voltage interrupting means for supplying and interrupting a voltage of a predetermined level input from the power supply according to an external interruption control signal; Voltage selection signal generating means for generating a polarization voltage selection signal for selecting a voltage corresponding to the frequency polarization of the satellite broadcasting signal by the polarization mode control signal according to the satellite broadcasting channel selection; The voltage of the predetermined level obtained by the voltage interrupting means is stabilized to the first and second polarization operating voltages corresponding to the frequency polarization, and any one of the polarization voltages is selected by the polarization voltage selection signal among the first and second polarization operating voltages. Polarization voltage generating means for selecting and providing the LNB to the LNB; And a polarization voltage interrupting means for detecting a level of the voltage provided to the low noise frequency converter and interrupting the voltage interrupting means when an abnormality occurs.

Preferably, the voltage selection signal generating means includes a switching element switched by a polarization mode control signal according to satellite broadcast channel selection; And a voltage drop part generated as a polarization voltage selection signal having a predetermined level by voltage-falling the first and second polarization operation voltages selected and selected by the polarization voltage generation means according to the switching of the switching element.

Preferably, the polarization voltage generating means comprises: first constant voltage means for lowering and outputting a voltage of a predetermined level obtained by the voltage regulating means to a first polarization operating voltage suitable for a satellite broadcast signal of a post wave; Second constant voltage means for lowering and outputting a voltage having a predetermined level obtained by the voltage interrupting means to a second polarization operating voltage suitable for a satellite broadcasting signal of left polarization; Voltage selection means for selecting and outputting any one of the first and second polarization operation voltages according to the polarization voltage selection signal of the voltage selection signal generation means; And filtering means for filtering and outputting the selected polarization operation voltage.

Preferably, the polarization voltage control means, the level detection unit for detecting the level of the polarization operation voltage generated by the polarization voltage generating means supplied to the LNB; And a switching element which is switched according to the voltage level detected by the level detecting unit to regulate the voltage interrupting means.

Preferably, the first polarization operating voltage is 14V and the second polarization operating voltage is 18V.

In accordance with another aspect of the present invention, a power supply protection device for an LNB may provide a power supply for a low noise frequency converter (LNB) for supplying an operating voltage to a low noise frequency converter for receiving a full band satellite broadcast signal. An apparatus comprising: voltage interrupting means for supplying and interrupting a voltage of a predetermined level input from the power supply according to an external interruption control signal; Voltage selection signal generating means for generating a polarization voltage selection signal for selecting a voltage corresponding to frequency polarization of the satellite broadcasting signal according to the polarization mode control signal according to the satellite broadcasting channel selection; The voltage of the predetermined level obtained by the voltage interrupting means is stabilized to the first and second polarization operating voltages corresponding to the frequency polarization, and any one of the polarization voltages is selected by the polarization voltage selection signal among the first and second polarization operating voltages. Polarization voltage generating means for selecting and providing the LNB to the LNB; And a polarization voltage interrupting means for detecting a level of a voltage provided to the low noise frequency converter and generating an interruption signal to the voltage interrupting means when an abnormality occurs. When the satellite broadcasting channel is selected, a polarization mode corresponding thereto is determined to provide a polarization mode control signal to the voltage selection signal generating means, and the character information stored in the font ROM is read based on the control signal obtained by the polarization voltage control means. A microprocessor; On-screen image generating means for converting the character information read by the microprocessor into an on-screen video signal to display the presence or absence of the LNB on the screen of the television receiver.

In this way, ideally, it can be seen that the LNB power is automatically shut off when an abnormality occurs due to leakage of the LNB installed in the outdoor parabola antenna in the state of receiving the broadband satellite broadcast signal. It can be seen that the abnormal state of the LNB is displayed on the screen.

As a result, the LNB installed in the outdoor parabola antenna can easily receive the left and the postal waves downlinked from the satellites, and the LNB stage power supply and the breakdown of the power supply terminal of the set stub box are prevented due to leakage.

And, there may be a plurality of embodiments of the present invention, the following will be described in detail with respect to the most preferred embodiment.

This preferred embodiment enables a better understanding of the objects, features and advantages of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the power supply protection device of the LNB according to the present invention.

In addition, in each figure used for description, the same component may be attached | subjected, and may show the same number, and the overlapping description may be abbreviate | omitted.

Fig. 2 is a circuit diagram showing an embodiment provided for explaining a power supply protection device of a low noise frequency converter (LNB) for satellite broadcasting reception according to the present invention.

According to this embodiment, the switch 200 for supplying and cutting off the 21V LNB operating voltage generated by the power supply and input through the power input terminal 204 according to an external control signal, and for selecting a satellite broadcasting channel. Accordingly, a polarization voltage selection signal for selecting a voltage corresponding to the frequency polarization of the satellite broadcasting signal is generated by a polarization mode control signal generated by an external microprocessor (not shown) and input through the input control terminal 205. The voltage selection signal generator 202 and the 21V LNB operating voltage input through the switch 200 are stabilized to the first and second polarization operating voltages corresponding to the corresponding frequency polarization, and the first and second polarization operation are performed. The polarization voltage generator 201 selects one polarization voltage by the polarization voltage selection signal generated by the voltage selection signal generator 202 and provides the LNB to the LNB through the output terminal 206. It consists of a polarization voltage interrupter 203 that detects the level of the voltage provided to the LNB and blocks the 21V LNB operating voltage input from the power input terminal 204 by opening the switch 200 when an abnormality occurs. do.

The voltage selection signal generator 202 is generated by the microprocessor according to the satellite broadcasting channel selection and is switched by the polarization mode control signal input through the input control terminal 205 and the resistors R4 and R5. The first and second polarization operating voltages selected and input by the polarization voltage generator 201 according to the switching of the first switching element Q1 and the first switching element Q1 are voltages through the resistors R1-R3. And a voltage drop section 202a that is strong and generates a polarization voltage selection signal having a constant level.

In addition, the polarization voltage generator 201 and the first constant voltage unit 201a for outputting the 21V LNB operating voltage input from the switch 200 to the first polarization operating voltage suitable for the satellite broadcasting signal of the post wave In the second constant voltage unit 201b and the voltage selection signal generator 202, the LNB operating voltage of 21 V input from the switch 200 is lowered to a second polarization operating voltage corresponding to the satellite broadcasting signal of the left polarization signal. The voltage selection signal generator 202 selects one of the first and second polarization operating voltages generated by the first and second constant voltage units 201a and 201b according to the generated polarization voltage selection signal. A voltage selector 201c provided to the voltage drop unit 202a and a diode D1 and a capacitor C1 which filter the selected polarization operation voltage and provide the LNB through the output terminal 206. It consists of a filtering unit 201d consisting of.

In addition, the polarization voltage interruption unit 203 divides the polarization operation voltage generated by the polarization voltage generation unit 201 and supplied to the LNB into resistors R6, R7, R8, and R9. A level detector 203a for maintaining and outputting the divided voltage at a constant level, and is switched according to the level of the voltage input from the level detector 203a to switch the voltage of the power supply terminal Vcc to ground through the resistor R10. The second switching device Q2 bypasses or provides the switch 200.

In addition, the signal downlinked from the satellite uses left polarization (LHCP) and postal wave (RHCP) to efficiently utilize the allocated frequency. In the LNB receiving the signal, the LNB operates with a power of 14V ± 1V. In the case of the left pile, it is operated with a power supply of 18V ± 1V.

With this assumption, the embodiment of the present invention will be described in more detail with reference to FIG. 2.

First, the LNB operating voltage is input from the power input terminal 204 of the LNB. At this time, since the stable voltage of 19 V or more is required for the input voltage of the power input terminal 204, an LNB operating voltage of 21 V is applied.

The input LNB operating voltage is input to the polarization voltage generator 201 through voltage interruption means such as the analog switch 200 by an interruption control signal provided from the polarization voltage interrupter 203 to be described later.

The polarization voltage generation unit 201 stabilizes and outputs the input 21V LNB operating voltage to the first and second polarization operating voltages corresponding to the frequency polarization of the satellite broadcasting signal.

In other words, the polarization voltage generator 201 includes first and second constant voltage units 201a and 201b, a voltage selector 201c, and a filter 201d.

Therefore, a regulator such as the first constant voltage unit 201a stabilizes the input LNB operating voltage of 21V to the first polarization operating voltage suitable for the postal wave of the satellite broadcasting signal, for example, stabilizes it to 14V and provides the voltage selection unit 201c. The second constant voltage unit 201b, such as a regulator, stabilizes the input 21V LNB operating voltage with a second polarization operating voltage suitable for the left polarization of the satellite broadcasting signal, for example, stabilizes it with 18V and provides the voltage selection unit 201c. Done.

Since the actual voltage used in the LNB is 14V or 18V as described above, it is possible to select a voltage corresponding to the frequency polarization of the satellite broadcast signal according to the dual satellite broadcast channel selection and provide the voltage to the LNB.

Accordingly, the voltage selector 201c selects one of the two input voltages 14V or 18V and provides the voltage to the voltage dropper 202a of the voltage selector signal generator 202 and the filtering unit 201d. In this case, the control of the voltage selector 201c is controlled by the polarization voltage selection signal generated by the voltage selection signal generator 202 and the polarization voltage selection signal is controlled by the polarization mode according to the satellite broadcasting channel selection. Generated by a signal.

In other words, when the viewer selects the satellite broadcasting channel through the settub box, the microprocessor determines the left and right waves of the satellite broadcasting signal corresponding to the channel and selects the polarization mode control signal through the control input terminal 205. The signal generator 202 is provided.

For example, when the satellite channel selected by the viewer is a postal file, a low polarization mode control signal is generated and a left polarization mode control signal is generated and provided to the control input terminal 205.

The polarization mode control signal input from the control input terminal 205 is provided to the base which is the control terminal of the first switching element Q1 through the resistors R4 and R5.

Accordingly, the switching element Q1 is turned off when the polarization mode control signal input through the resistors R4 and R5 is low.

When the switching element Q1 of the voltage selection signal generator 202 is cut off, the resistors R1-R3 of the voltage drop unit 202a receive the voltage provided from the voltage selection unit 201c to the first switching element Q1. The voltage selector 201c is switched to the first constant voltage unit 201a by switching the voltage selector 201c to the first constant voltage unit 201a by not allowing the voltage to be grounded to the ground and dropping the voltage to a predetermined level, for example, by a polarization voltage selection signal of 5V. At 14V, the voltage is continuously output to the filtering unit 201d and the voltage drop unit 202a.

When the polarization mode control signal input through the control input terminal 205 and the resistors R4 and R5 is high (left polarization mode), the first switching element Q1 is turned on.

When the switching element Q1 is conducted, the voltage of the voltage selector 201c, which has been dropped from the resistors R1-R3 of the voltage drop part 202a, is bypassed to ground through the first switching element Q1. In the first switching element Q1, a polarization voltage selection signal having a low potential is generated to switch the voltage selection unit 201c to the second constant voltage unit 201b. Therefore, the voltage selector 201c continuously outputs a voltage of 18V and is provided to the filtering unit 201d and the voltage drop unit 202a.

In addition, the voltage selected according to the polarization mode in the voltage selector 201c such as an analog switch is rectified through the filtering unit D1 and provided to the polarization voltage interrupter 203 after the noise is removed from the capacitor C1. The terminal 206 is provided with an operating voltage to the LNB.

The polarization voltage interrupter 203 periodically detects the level of the voltage generated by the polarization voltage generator 201 and provided to the LNB to shut off the above-described switch 200 when an abnormality occurs.

Here, the polarization voltage interruption unit 203 includes a voltage level detection unit 203a and a second switching element Q2.

Therefore, when the LNB operates normally, the voltage of 14 V or 18 V generated by the polarization voltage generator 201 causes the resistors R6, R7, R8, and R9 of the voltage level detector 203a. And the voltage divided by the resistor R6 and R7 is maintained at a constant voltage level, for example, at 5V to conduct the second switching element Q2 so that the voltage of the power supply terminal Vcc is increased. Bypass to the ground through the second switching element (Q2).

Accordingly, the above-described switch 200 continues to be connected by the interruption control signal provided from the polarization voltage interrupter 203, that is, a low signal, so that the LNB operating voltage input from the power input terminal 204 is polarized to generate the polarization voltage generator 201. ) Will be provided.

In such a state, when the power supply of the LNB installed in the outdoor parabola antenna is shorted due to leakage of snow or boiling, the voltage of the output terminal 206 is reduced at this time, so that the resistances R6 to R9 of the level detection unit 203a are reduced. The voltage through) also becomes low to turn off the second switching element Q2.

When the second switching element Q2 is cut off, the voltage of the power supply terminal Vcc, that is, the voltage of 5V opens the above-described switch 200, so that the 21V LNB input from the power supply input terminal 204 is eventually obtained. The operating voltage is cut off to protect the power stage inside the set.

In this case, in order to eliminate the constant accident of the LNB, the control signal is generated by the polarization voltage control unit 203 and the control signal is provided to the microprocessor without directly interrupting the switch 200 to short-circuit the LNB. It is preferable to allow the microprocessor to directly control the switch 200 according to the determination.

3 is a circuit configuration diagram showing another embodiment provided in the description of the power supply protection device of the LNB for receiving satellite broadcasting, by which an abnormality of the LNB can be displayed on the screen through a television receiver. Parts having the same constituents as 2 are denoted by the same reference numerals and description thereof will be omitted.

As described above, when the satellite broadcasting channel is selected, the polarization mode corresponding thereto is determined to provide the polarization mode control signal to the voltage selection signal generator 202 and based on the intermittent control signal input from the polarization voltage interrupter 203. Reads and outputs the character information stored in the font ROM 208, and converts the character information input from the microprocessor 208 and the microprocessor 207 into on-screen video signals. An on-screen image generator 209 and an image mixer for switching the on-screen image signal and the image signal (CPSV) processed by the MPEG processing means (not shown) of the set-tub box to the television receiver 211. It consists of 210.

In the power supply protection device of the LNB for satellite broadcast reception configured as described above, the microprocessor 207 determines the left and right wave modes according to the satellite broadcast channel selected by the viewer, and controls the polarization mode to the voltage selection signal generator 202. The signal is provided and the switch 200 is provided with an intermittent low signal to continuously monitor the polarization voltage interrupter 203 while operating the LNB in the same manner as in FIG. 2.

At this time, when the interruption control signal is input low from the polarization voltage interruption unit 203, the above-described switch 200 is continuously shorted (ShRT) so that the LNB operating voltage of the power input terminal 204 is transmitted to the polarization voltage generator 201. Will be provided.

However, if an abnormality occurs in the LNB and the interruption control signal is input high by the polarization voltage interruption unit 203, the microprocessor 207 opens the switch 200 to inform the viewer of the LNB, thereby operating the voltage of the LNB. In addition, the character data stored in the font ROM 208 is read and provided to the on-screen image generator 209.

The on-screen image generation unit 209 converts the input text data into an on-screen image signal and provides the converted image data to the image mixing unit 210.

The video mixing unit 210 switches the input on-screen video signal and the video signal provided by the MPEG processing means in the set-tub box to display the abnormal state of the LNB on the screen of the television receiver as on-screen text.

On the other hand, when the power supply of the LNB is short-circuited by the conventional configuration, that is, the rain or snow leakage, as a comparative example, the present invention is unlikely to receive satellite broadcasting and to damage the power terminal elements of the LNB and the settub box. The LNB can automatically cut off the power of the LNB when an abnormality occurs due to a leak in the LNB and display it on the screen.

As a result, the LNB installed in the outdoor parabola antenna can easily receive the left and the postal waves which are downlinked from the satellite, and can prevent the breakage of the LNB terminal power terminal and the set stub box due to leakage. I can see.

And while specific embodiments of the present invention have been described and illustrated above, it will be apparent that the present invention may be embodied in various modifications by those skilled in the art.

Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

It is clear from the above description that, according to the power supply protection device of the LNB of the present invention, the LNB can easily receive the left polarized wave and the postal wave downlinked from the satellite by generating an operating voltage corresponding to the frequency polarized wave, It is possible to prevent burnout of the LNB power terminal and the power terminal elements of the settub box due to leakage, rain, etc.

In addition, it is possible to quickly deal with the abnormal state of the LNB by displaying the abnormal state of the LNB directly on the screen of the television receiver.

Claims (13)

In a power supply unit of an LNB that supplies an operating voltage to a low noise blocker (LNB) that receives a full band satellite signal: Voltage interrupting means for supplying and interrupting an input voltage of a predetermined level according to an external interruption control signal; Voltage selection signal generating means for generating a polarization voltage selection signal for selecting a voltage corresponding to frequency polarization of the satellite broadcasting signal according to the polarization mode control signal according to the satellite broadcasting channel selection; The voltage of the predetermined level obtained by the voltage interrupting means is stabilized to the first and second polarization operating voltages corresponding to the frequency polarization, and one of the polarization voltages is selected by the polarization voltage selection signal among the first and second polarization operating voltages. Polarization voltage generating means for selecting a voltage and providing the voltage to the LNB; And And a polarization voltage interrupting means for detecting a level of the voltage provided to the LNB to interrupt the voltage interrupting means and interrupting the voltage at the predetermined level when an abnormality occurs. The method of claim 1, The voltage selection signal generating means includes a first switching element switched by a polarization mode control signal according to the satellite broadcasting channel selection; A low noise frequency converter comprising a voltage drop generated as a polarization voltage selection signal having a predetermined level by voltage-falling the first and second polarization operation voltages selected by the polarization voltage generating means according to the switching of the first switching element; Power supply protection device. The method of claim 2, And the voltage drop unit comprises a resistor connected in series with the output terminal of the polarization voltage generating means, the collector of the first switching element, and the ground. The method of claim 1, The polarization voltage generating means may include: first constant voltage means for lowering and outputting a voltage having a predetermined level obtained by the voltage interrupting means to a first polarization operation voltage suitable for a satellite broadcast signal of a post wave; Second constant voltage means for lowering and outputting a voltage having a predetermined level obtained by the voltage interrupting means to a second polarization operating voltage suitable for a satellite broadcasting signal of left polarization; Voltage selection means for selecting and outputting any one of the first and second polarization operation voltages according to the polarization voltage selection signal of the voltage selection signal generation means; And And a filtering means for filtering the selected polarized operating voltage and providing the LNB to the LNB. The method of claim 1, The polarization voltage interrupting means includes a level detection section for detecting the level of the polarization operating voltage generated by the polarization voltage generating means and supplied to the LNB; And a second switching element for switching according to the voltage level detected by the level detecting unit to control the voltage interrupting means. The method of claim 5, The level detecting unit includes two resistors connected in series between the output terminal of the polarization voltage generating means and ground to lower the polarization voltage to a predetermined voltage; A power supply protection device for a low noise frequency converter comprising two resistors connected in common between a connection point of the two resistors and a ground to provide a voltage drop across the two resistors to a control terminal of the switching element. The method of claim 1, The power supply protection device of a low noise frequency converter, characterized in that the voltage of the predetermined level is 21V. The method according to claim 1 or 4, The first polarization operating voltage is 14V and the second polarization operating voltage is a power supply protection device for a low noise frequency converter, characterized in that 18V. In a low noise block converter (LNB) power supply for supplying an operating voltage to a low noise frequency converter that receives a full band satellite broadcast signal: Voltage interrupting means for supplying and interrupting an input voltage of a predetermined level according to an external interruption control signal; Voltage selection signal generating means for generating a polarization voltage selection signal for selecting a voltage corresponding to frequency polarization of the satellite broadcasting signal according to a polarization mode control signal according to satellite broadcasting channel selection; The voltage of the predetermined level obtained by the voltage interrupting means is stabilized to the first and second polarization operating voltages corresponding to the frequency polarization, and any one of the polarization voltages is selected by the polarization voltage selection signal among the first and second polarization operating voltages. Polarization voltage generating means for selecting and providing the LNB to the LNB; Polarization voltage interrupting means for detecting a level of the voltage provided to the LNB and generating the interruption control signal when an abnormality occurs; Determine a polarization mode corresponding to the selection of the satellite broadcasting channel, provide a polarization mode control signal to the voltage selection signal generating means, and control the voltage regulation means based on the regulation control signal obtained from the polarization voltage regulation means; A microprocessor for reading character information stored in the font ROM; And And an on-screen image generating means for converting the character information read by the microprocessor into an on-screen video signal to display an abnormality of the LNB on a screen of a television receiver. The method of claim 9, The voltage selection signal generating means includes a first switching element switched by a polarization mode control signal of the microprocessor; A low noise frequency, characterized in that it comprises a voltage drop generated as a polarization voltage selection signal having a predetermined level by voltage-falling the first and second polarization operation voltage selected by the polarization voltage generating means according to the switching of the first switching element. Power supply protection of the converter. The method of claim 9, The polarization voltage generating means may include: first constant voltage means for lowering and outputting a voltage having a predetermined level obtained by the voltage interrupting means to the first polarization operation voltage suitable for a satellite broadcast signal of a post wave; Second constant voltage means for lowering and outputting a voltage having a predetermined level obtained by the voltage interrupting means to the second polarization operating voltage suitable for a satellite broadcasting signal of left polarization; Voltage selection means for selecting and outputting any one of the first and second polarization operation voltages according to the polarization voltage selection signal of the voltage selection signal generation means; And And a filtering means for filtering the selected polarized operating voltage and providing the LNB to the LNB. The method of claim 9, The polarization voltage interrupting means includes a level detection section for detecting the level of the polarization operating voltage generated by the polarization voltage generating means and supplied to the LNB; And a second switching element for switching according to the voltage level detected by the level detecting unit to control the voltage interrupting means. The method of claim 9, The power supply protection device of a low noise frequency converter, characterized in that the voltage of the predetermined level is 21V.