CN102710915B - LNB (Low Noise Block) power supply control circuit - Google Patents
LNB (Low Noise Block) power supply control circuit Download PDFInfo
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Abstract
The invention relates to an LNB (Low Noise Block) power supply control circuit comprising an LNB power switch circuit, a boosted circuit, a square wave control circuit and a voltage conversion control circuit, and also comprising a power switch signal end, a voltage conversion signal end, a square wave signal end, an LNB voltage input end and an LNB voltage output end, wherein the power switch signal end is connected with the input end of the LNB power switch circuit, the output end of the LNB power switch circuit is connected with the input end of the boosted circuit; the voltage conversion signal end is connected with the output end of the voltage conversion control circuit, and the voltage conversion control circuit is connected with the boosted circuit; the square wave control circuit comprises a second diode and a triode, wherein the anode of the second diode is connected with the LNB voltage input end, and the cathode of the second diode is connected with the output end of the boosted circuit; and the triode is connected with the square wave signal end, is used for controlling the conduction or short circuit of the second diode by 22KHZ square wave signals so as to adjust the output voltage of the LNB voltage output end.
Description
Technical Field
The present invention relates to digital satellite receivers, and more particularly, to an LNB power supply control circuit for a digital satellite receiver.
Background
With the development of digital television technology, digital satellite receivers are more and more widely used. In the current LNB power supply control circuit of the digital satellite receiver, 33V voltage is generally adopted to be converted into 18V/13V voltage through a linear voltage regulator LM 317. The digital satellite receiver has low efficiency and large heat productivity, and needs to be additionally provided with large radiating fins, so that the cost of the digital satellite receiver is increased.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide an LNB power supply control circuit with low cost, convenient debugging and short circuit protection function, aiming at the above-mentioned defects in the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows:
an LNB power supply control circuit is constructed, and comprises an LNB power supply switch circuit 10, a boost circuit, a square wave control circuit and a voltage conversion control circuit, and further comprises a power supply switch signal end for controlling whether to supply power to a receiver, a voltage conversion signal end LNB _13/18V for controlling the voltage provided for the receiver, a square wave signal end for accessing a 22KHZ square wave signal, an LNB voltage input end and an LNB voltage output end, wherein the input voltage of the LNB voltage input end is smaller than the output voltage of the LNB voltage output end, the power supply switch signal end and the LNB voltage input end are connected with the input end of the LNB power supply switch circuit 10, and the output end of the LNB power supply switch circuit 10 is connected with the input end of the boost circuit;
the voltage conversion signal end LNB _13/18V is connected with the output end of the voltage conversion control circuit, and the voltage conversion control circuit is connected with the boosting circuit to control the boosting circuit to output 13V or 18V voltage;
the square wave control circuit comprises a second diode, the anode of the second diode is connected with the LNB voltage output end, and the cathode of the second diode is connected with the output end of the booster circuit;
the square wave control circuit further comprises a triode combination which is connected with the square wave signal end and used for controlling the conduction or short circuit of the second diode through the 22KHZ square wave signal so as to adjust the output voltage of the LNB voltage output end.
The LNB power supply control circuit comprises a triode combination, a first triode and a second triode, wherein the triode combination comprises an NPN type fourth triode and a PNP type fifth triode; wherein,
an emitting electrode of the fourth triode is grounded, a base electrode of the fourth triode is connected with the square wave signal end, and a collector electrode of the fourth triode is connected with a base electrode of the fifth triode through an eighth resistor;
the base electrode of the fifth triode is connected with the LNB voltage output end through a seventh resistor, the collector electrode of the fifth triode is connected with the negative electrode of the second diode, and the emitter electrode of the fifth triode is connected with the positive electrode of the second diode and the LNB voltage output end.
The LNB power supply control circuit of the present invention, wherein the LNB power switch circuit 10 includes a first fet of P channel enhancement type, a second triode of NPN type, a first resistor and a second resistor; wherein,
the base electrode of the second triode is connected with the signal end of the power switch, the emitting electrode of the second triode is grounded, and the collector electrode of the second triode is connected with the LNB voltage input end through the series circuit of the second resistor and the first resistor;
the grid electrode of the first field effect transistor is connected between the first resistor and the second resistor, the source electrode of the first field effect transistor is connected with the LNB voltage input end, and the drain electrode of the first field effect transistor is connected with the input end of the booster circuit.
The LNB power supply control circuit comprises a boost circuit, a first resistor, a second filter capacitor and a divider resistor combination, wherein the boost circuit comprises a third resistor, a switch chip for completing boost, an inductor, a first diode and the second filter capacitor, and the divider resistor combination is used for outputting 13V or 18V voltage; wherein,
the utility model discloses a switch chip's voltage divider, including switch chip, third resistance connection, first field effect transistor's drain electrode, switch chip's enable end warp the third resistance connection the drain electrode of first field effect transistor, switch chip's input is connected the drain electrode of first field effect transistor, the inductance is connected between switch chip's input and switching signal end, the switching signal end is connected the positive pole of first diode, the negative pole of first diode is connected the positive pole of second filter capacitor, second filter capacitor's negative pole ground connection, switch chip's feedback end is connected the voltage divider combination, be used for the voltage divider combination provides the voltage of fixed size, switch chip's earthing terminal ground connection.
The LNB power supply control circuit comprises a voltage division resistor combination, a voltage conversion control circuit and a control circuit, wherein the voltage division resistor combination comprises a fourth resistor, a fifth resistor and a sixth resistor; wherein,
the base electrode of the third triode is connected with the voltage conversion signal end LNB _13/18V, the emitter electrode of the third triode is grounded, and the base electrode of the third triode is connected with the feedback end of the switch chip through the sixth resistor;
one end of the fifth resistor is grounded, and the other end of the fifth resistor is connected with the feedback end of the switch chip;
one end of the fourth resistor is connected with the feedback end of the switch chip, and the other end of the fourth resistor is connected with the cathode of the second diode.
The LNB power supply control circuit provided by the invention is characterized in that the drain electrode of the first field effect transistor is grounded through a first coupling capacitor.
The LNB power supply control circuit further comprises an overcurrent short-circuit protection circuit, wherein the overcurrent short-circuit protection circuit comprises a PNP type sixth triode, a third diode and a ninth resistor; wherein,
the collector of the sixth triode is a protection signal end and is connected with the grid of the first field effect transistor, the base of the sixth triode is connected with the LNB voltage output end through the ninth resistor, the emitter of the sixth triode is connected with the emitter of the fifth triode and the anode of the third diode, and the cathode of the third diode is connected with the LNB voltage output end.
According to the LNB power supply control circuit, the feedback end of the switch chip provides a fixed voltage of 0.6V or 0.9V.
According to the LNB power supply control circuit, the LNB voltage input end is connected with 12V voltage.
The invention has the beneficial effects that: the voltage output of 13V or 18V is realized by adopting the booster circuit, so that the universal 12V voltage can be adopted for supplying power, and the use is more convenient; meanwhile, the output voltage of the LNB voltage output end is adjusted by adopting the cooperation of the triode combination and the second diode, so that the circuit is simplified, the LNB power supply control circuit is low in cost, the realization is simple, and the debugging is more convenient.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a functional block diagram of the LNB power control circuitry of the preferred embodiment of the invention;
fig. 2 is a detailed schematic diagram of the LNB power supply control circuit of the preferred embodiment of the present invention.
Detailed Description
Fig. 1 shows a schematic block diagram of an LNB power supply control circuit according to a preferred embodiment of the present invention, where the LNB power supply control circuit includes an LNB power switch circuit 10, a boost circuit 20, a square wave control circuit 30, and a voltage conversion control circuit 50, and further includes a power switch signal terminal for controlling whether to supply power to a receiver, a voltage conversion signal terminal LNB _13/18V for controlling the voltage supplied to the receiver, a square wave signal terminal for accessing a 22KHZ square wave signal, an LNB voltage input terminal, and an LNB voltage output terminal, where an input voltage of the LNB voltage input terminal is less than an output voltage of the LNB voltage output terminal. The power switch signal end and the LNB voltage input end are connected with the input end of the LNB power switch circuit 10, and the output end of the LNB power switch circuit 10 is connected with the input end of the booster circuit 20; the voltage conversion signal terminal LNB _13/18V is connected to the output terminal of the voltage conversion control circuit 50, and the voltage conversion control circuit 50 is connected to the voltage boost circuit 20 to control the voltage boost circuit 20 to output a voltage of 13V or 18V.
As shown in fig. 2, the square wave control circuit 30 includes a second diode D2, an anode of the second diode D2 is connected to the LNB voltage output terminal LNB _ OUT, and a cathode of the second diode D2 is connected to the output terminal of the voltage boost circuit 20. The square wave control circuit 30 further includes a triode combination connected to the square wave signal terminal 22K for controlling the conduction or short-circuiting of the second diode D2 by the 22KHZ square wave signal to adjust the magnitude of the output voltage at the LNB voltage output terminal LNB _ OUT. The LNB voltage input end VCC is preferably connected with 12V voltage; the receiver is a digital satellite receiver.
After the lower voltage accessed from the LNB voltage input terminal VCC is boosted by the boost circuit 20, the voltage of 13V or 18V is obtained under the control of the voltage conversion control circuit 50, then the square wave signal terminal 22K accesses the 22KHZ square wave signal, the 22KHZ square wave signal controls the triode combination of the square wave control circuit 30 to adjust the conduction or short circuit of the second diode D2, when the second diode D2 is conducted, the conduction voltage drop of 700mV is generated and added to the output terminal of the boost circuit 20, and when the second diode D2 is short-circuited, the voltage of the output terminal of the boost circuit 20 is unchanged, so that the output voltage of the LNB voltage output terminal LNB _ OUT is adjusted, and the 22K alternating current signal is generated. Because the booster circuit 20 is adopted to realize the voltage output of 13V or 18V, the universal 12V voltage can be adopted to supply power, and the use is more convenient; meanwhile, the adjustment of the output voltage of the LNB voltage output end LNB _ OUT is realized by adopting the cooperation of the triode combination and the second diode D2, so that the circuit is simplified, the LNB power supply control circuit is low in cost, the realization is simple, and the debugging is more convenient.
Further, in the above embodiment, as shown in fig. 1 and fig. 2, the transistor combination includes a fourth transistor Q4 and a fifth transistor Q5, the fourth transistor Q4 is an NPN transistor, and the fifth transistor Q5 is a PNP transistor. An emitting electrode of the fourth triode Q4 is grounded, a base electrode of the fourth triode Q4 is connected with the square wave signal end 22K, and a collector electrode of the fourth triode Q4 is connected with a base electrode of the fifth triode Q5 through an eighth resistor; the base of the fifth transistor Q5 is connected to the LNB voltage output terminal LNB _ OUT through a seventh resistor R7, the collector of the fifth transistor Q5 is connected to the cathode of the second diode D2, and the emitter of the fifth transistor Q5 is connected to the anode of the second diode D2 and the LNB voltage output terminal LNB _ OUT.
Specifically, when the 22KHZ square wave signal is at a low level, the base of the fourth transistor Q4 is at a low level, the fourth transistor Q4 is turned off, so that the base of the fifth transistor Q5 is the same as the emitter voltage, the fifth transistor Q5 is turned off, the second diode D2 is turned on, the output voltage of the LNB voltage output end LNB _ OUT is increased by the conduction voltage drop 0.7V of the second diode D2 on the basis of the output voltage of the boost circuit 20, the output voltage of the boost circuit 20 can be 13.8V/18.7V by setting the specific component parameters of the boost circuit 20, and the output voltage of the LNB voltage output end LNB _ OUT is 14.5V/19.4V.
When the 22KHZ square wave signal is at a high level, the fourth transistor Q4 is turned on, the seventh resistor R7 and the eighth resistor form a voltage dividing circuit to pull down the voltage at the base of the fifth transistor Q5, so that the fifth transistor Q5 is turned on, and since the ues of the fifth transistor Q5 is equal to 0V, the second diode D2 is short-circuited, so that the output voltage at the LNB voltage output terminal LNB _ OUT becomes 13.8V/18.7V.
Meanwhile, when the 22KHZ square wave signal is at a high level, a 22K alternating current control signal appears at the LNB voltage output end LNB _ OUT, and it can be shown that, at this time, the output voltage dc component of the LNB voltage output end LNB _ OUT is 14.15V/19.05V, the alternating current component is an alternating current signal with a frequency of 22KHZ and an amplitude of 700mV, and the alternating current signal is commonly used as a satellite switching function in the LNB power supply system.
Further, in the above-described embodiment, as shown in fig. 1 and fig. 2, the LNB power switch circuit 10 includes a first NPN-type fet Q1, a second NPN-type transistor Q2, a first resistor R1, and a second resistor R2, and the first fet Q1 is preferably a P-channel enhancement fet. The base electrode of the second triode Q2 is connected with a power switch signal end LNB _ ON/OFF, the emitter electrode of the second triode Q2 is grounded, and the collector electrode of the second triode Q2 is connected with the LNB voltage input end VCC through the series circuit of the second resistor R2 and the first resistor R1; the gate of the first fet Q1 is connected between the first resistor R1 and the second resistor R2, the source of the first fet Q1 is connected to the LNB voltage input VCC, and the drain of the first fet Q1 is connected to the input of the boost circuit 20. When the power switch signal end LNB _ ON/OFF is at a low level, the first field effect tube Q1 is cut OFF, and the LNB power supply control circuit has no voltage output; when the power switch signal terminal LNB _ ON/OFF is at a high level, the second transistor Q2 is turned ON, the voltage is divided by the first resistor R1 and the second resistor R2, the gate voltage of the first fet Q1 is pulled low, and the first fet Q1 is turned ON, so that the voltage boost circuit 20 is powered ON.
Further, in the above-described embodiment, as shown in fig. 1 and fig. 2, the voltage boost circuit 20 includes the third resistor R3, the switch chip U for completing the voltage boost, the inductor L, the first diode D1, the second filter capacitor C2, and the voltage dividing resistor combination for outputting the voltage of 13V or 18V. The enable end EN of the switch chip U is connected with the drain electrode of the first field-effect tube Q1 through a third resistor R3, the input end VIN of the switch chip U is connected with the drain electrode of the first field-effect tube Q1, the inductor L is connected between the input end VIN of the switch chip U and the switch signal end LX, the switch signal end LX is connected with the anode of the first diode D1, the cathode of the first diode D1 is connected with the anode of the second filter capacitor C2, the cathode of the second filter capacitor C2 is grounded, the feedback end FB of the switch chip U is connected with the divider resistor combination and used for providing fixed-size voltage for the divider resistor combination, and the ground end GND of the ground terminal of the switch chip U is grounded. Preferably, the fixed voltage magnitude is 0.6V or 0.9V; the first diode D1 is a rectifier diode, and the second filter capacitor C2 functions as a filter for outputting a direct current.
Specifically, as shown in fig. 2, the voltage dividing resistor combination includes a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, and the voltage conversion control circuit 50 includes an NPN-type third transistor Q3; the base electrode of the third triode Q3 is connected with the voltage conversion signal end LNB _13/18V, the emitter electrode of the third triode Q3 is grounded, and the base electrode of the third triode Q3 is connected with the feedback end FB of the switch chip U through the sixth resistor R6; one end of the fifth resistor R5 is grounded, and the other end of the fifth resistor R5 is connected with the feedback end FB of the switch chip U; one end of the fourth resistor R4 is connected to the feedback terminal FB of the switch chip U, and the other end of the fourth resistor R4 is connected to the cathode of the second diode D2.
When the voltage conversion signal terminal LNB _13/18V is a low level signal, the third transistor Q3 is turned off, and the voltage of the positive electrode of the second diode D2 is: 0.6 × (R755/R757 +1) = 13.8V; when the voltage conversion signal terminal LNB _13/18V is at a high level, the third transistor Q3 is turned on, the fifth resistor R5 and the sixth resistor R6 are connected in parallel, and the voltage of the positive electrode of the second diode D2 is: 0.6 = (R755/(R757R | | 758) +1) = 18.7V. The resistance ranges of the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are 1-100 kilo-ohms, specific resistance values can be selected according to needs, and only the voltage of 13.8V and the voltage of 18.7V can be obtained according to the calculation formula.
Preferably, in the above embodiment, as shown in fig. 2, the drain of the first field effect transistor Q1 is further grounded through the first coupling capacitor C1, so as to increase the system stability. Specifically, when the switching signal terminal LX of the switch chip U is pulled down, the current is too large, which tends to make the voltage at the LNB voltage input terminal VCC unstable, and the first coupling capacitor C1 can play a role in buffering.
Further, in the above embodiment, as shown in fig. 1 and fig. 2, the LNB power supply control circuit further includes an overcurrent short-circuit protection circuit 40, and the overcurrent short-circuit protection circuit 40 includes a PNP-type sixth transistor Q6, a third diode D3, and a ninth resistor R9. The collector of the sixth triode Q6 is a PROTECTION signal terminal PROTECTION and is connected to the gate of the first fet Q1, the base of the sixth triode Q6 is connected to the LNB voltage output terminal LNB _ OUT through the ninth resistor R9, the emitter of the sixth triode Q6 is connected to the emitter of the fifth triode Q5 and the anode of the third diode D3, and the cathode of the third diode D3 is connected to the LNB voltage output terminal LNB _ OUT.
When the LNB power supply control circuit is not started to work, the sixth triode Q6 is cut off, namely suspended, because the LNB voltage output end LNB _ OUT has no current, and the overcurrent short-circuit protection circuit 40 does not work; when the LNB power supply control circuit works, the threshold value of the output current can be adjusted by setting the resistance value of the ninth resistor R9, and the characteristic that the diode voltage drop changes along with the change of the output current is utilized, when the output current exceeds the set threshold value, the voltage drop of the third diode D3 is large enough, the ninth resistor R9 controls the base current of the sixth triode Q6 to control the conduction of the sixth triode Q6, at the moment, the collector of the sixth triode Q6 outputs high voltage, the high voltage is used as an overcurrent PROTECTION signal of a PROTECTION signal terminal PROTECTION, the grid voltage of the first field effect transistor Q1 is pulled up forcibly, so that the first field effect transistor Q1 is cut off, the LNB power supply is cut off, and the overcurrent PROTECTION function is achieved. Meanwhile, the PROTECTION signal terminal PROTECTION can be connected to the main chip, when the main chip receives the overcurrent PROTECTION signal, the power switch signal terminal LNB _ ON/OFFLNB _ ON/OFF should be pulled down in time, and the user is prompted to output short-circuit information.
In summary, the booster circuit 20 is adopted to realize the voltage output of 13V or 18V, so that the universal 12V voltage can be adopted to supply power, and the use is more convenient; meanwhile, the adjustment of the output voltage of the LNB voltage output end LNB _ OUT is realized by adopting the cooperation of the triode combination and the second diode D2, the circuit is simplified, the LNB power supply control circuit is low in cost, the realization is simple, and the debugging is more convenient.
In addition, in a further embodiment of the present invention, by providing the overcurrent short-circuit protection circuit 40, the characteristic that the diode voltage drop changes with the change of the output current is utilized, and the LNB power supply is cut off when the current is too large, so that the overcurrent protection effect is achieved.
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
Claims (6)
1. An LNB power supply control circuit comprises an LNB power supply switch circuit (10), a boost circuit (20), a square wave control circuit (30), an overcurrent short-circuit protection circuit (40) and a voltage conversion control circuit (50), and further comprises a power supply switch signal end for controlling whether to supply power to a receiver, a voltage conversion signal end for controlling the voltage supplied to the receiver, a square wave signal end for accessing a 22KHZ square wave signal, an LNB voltage input end and an LNB voltage output end, wherein the input voltage of the LNB voltage input end is smaller than the output voltage of the LNB voltage output end, the LNB power supply switch signal end and the LNB voltage input end are connected with the input end of the LNB power supply switch circuit (10), and the output end of the LNB power supply switch circuit (10) is connected with the input end of the boost circuit (20);
the voltage conversion signal end is connected with the input end of the voltage conversion control circuit (50), and the output end of the voltage conversion control circuit (50) is connected with the boosting circuit (20) to control the boosting circuit (20) to output 13V or 18V voltage;
the square wave control circuit (30) comprises a second diode (D2), the anode of the second diode (D2) is connected with the LNB voltage output end, and the cathode of the second diode (D2) is connected with the output end of the boosting circuit (20);
the square wave control circuit (30) further comprises a triode combination which is connected with the square wave signal end and is used for controlling the conduction or short circuit of the second diode (D2) through the 22KHZ square wave signal so as to adjust the output voltage of the LNB voltage output end;
the triode combination comprises a fourth triode (Q4) of NPN type and a fifth triode (Q5) of PNP type; wherein the emitter of the fourth triode (Q4) is grounded, the base of the fourth triode (Q4) is connected with the square wave signal end, and the collector of the fourth triode (Q4) is connected with the base of the fifth triode (Q5) through an eighth resistor (R8);
the base electrode of the fifth triode (Q5) is connected with the LNB voltage output end through a seventh resistor (R7), the collector electrode of the fifth triode (Q5) is connected with the cathode electrode of the second diode (D2), and the emitter electrode of the fifth triode (Q5) is connected with the anode electrode of the second diode (D2) and the LNB voltage output end;
the LNB power switch circuit (10) comprises a first field effect transistor (Q1) of a P-channel enhancement type, a second triode (Q2) of an NPN type, a first resistor (R1) and a second resistor (R2); wherein,
the base electrode of the second triode (Q2) is connected with the power supply switching signal end, the emitter electrode of the second triode (Q2) is grounded, and the collector electrode of the second triode (Q2) is connected with the LNB voltage input end through the series circuit of the second resistor (R2) and the first resistor (R1);
the grid electrode of the first field effect transistor (Q1) is connected between the first resistor (R1) and the second resistor (R2), the source electrode of the first field effect transistor (Q1) is connected with the LNB voltage input end, and the drain electrode of the first field effect transistor (Q1) is connected with the input end of the boosting circuit (20);
the overcurrent short-circuit protection circuit (40) comprises a PNP type sixth triode (Q6), a third diode (D3) and a ninth resistor (R9); the collector of the sixth triode (Q6) is a protection signal terminal and is connected with the gate of the first field effect transistor (Q1), the base of the sixth triode (Q6) is connected with the LNB voltage output terminal through the ninth resistor (R9), the emitter of the sixth triode (Q6) is connected with the emitter of the fifth triode (Q5) and the anode of the third diode (D3), and the cathode of the third diode (D3) is connected with the LNB voltage output terminal.
2. The LNB power supply control circuit of claim 1, wherein the boost circuit (20) comprises a third resistor (R3), a switch chip (U) for accomplishing the boost, an inductor (L), a first diode (D1), a second filter capacitor (C2), and a divider resistor combination for outputting a voltage of 13V or 18V; wherein, the enable end of switch chip (U) is through third resistance (R3) is connected the drain electrode of first field effect transistor (Q1), the input of switch chip (U) is connected the drain electrode of first field effect transistor (Q1), inductance (L) is connected between the input of switch chip (U) and the switching signal end, the switching signal end is connected the positive pole of first diode (D1), the negative pole of first diode (D1) is connected the positive pole of second filter capacitor (C2), the negative pole ground connection of second filter capacitor (C2), the feedback end of switch chip (U) is connected the divider resistance combination, is used for providing the voltage of fixed size for the divider resistance combination, the earthing terminal ground connection of switch chip (U).
3. The LNB power supply control circuit of claim 2, wherein said voltage divider resistor combination comprises a fourth resistor (R4), a fifth resistor (R5) and a sixth resistor (R6), and said voltage conversion control circuit (50) comprises a third transistor (Q3) of NPN type; wherein the base of the third transistor (Q3) is connected to the voltage conversion signal terminal, the emitter of the third transistor (Q3) is grounded, and the base of the third transistor (Q3) is connected to the feedback terminal of the switch chip (U) through the sixth resistor (R6);
one end of the fifth resistor (R5) is grounded, and the other end of the fifth resistor (R5) is connected with the feedback end of the switch chip (U);
one end of the fourth resistor (R4) is connected with the feedback end of the switch chip (U), and the other end of the fourth resistor (R4) is connected with the cathode of the second diode (D2).
4. The LNB power supply control circuit of claim 1, wherein the drain of the first fet (Q1) is further coupled to ground through a first coupling capacitor (C1).
5. The LNB power supply control circuit of claim 2, wherein the switch chip (U) feedback provides a fixed voltage level of 0.6V or 0.9V.
6. The LNB power supply control circuit of claim 1, wherein the LNB voltage input is connected to a 12V voltage.
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| CN201509264U (en) * | 2009-10-19 | 2010-06-16 | 浙江博尚电子有限公司 | LNB power supply circuit with short-circuit protection function |
| CN201986058U (en) * | 2011-01-10 | 2011-09-21 | 青岛海信电器股份有限公司 | LNB power supply circuit and television |
| CN202095020U (en) * | 2011-06-02 | 2011-12-28 | 深圳市视维科技有限公司 | Low noise block (LNB) power supply control circuit of digital television set top box |
| CN102263916A (en) * | 2011-06-07 | 2011-11-30 | 深圳市九洲电器有限公司 | LNB (Low Noise Block) power supply control circuit, power supply control system and digital set-top box |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107918380A (en) * | 2017-11-30 | 2018-04-17 | 惠州市蓝微新源技术有限公司 | A kind of control circuit of MCU break-makes |
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| CN102710915A (en) | 2012-10-03 |
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