CN203289074U - Power supply direct-supply protection circuit and set-top box - Google Patents

Power supply direct-supply protection circuit and set-top box Download PDF

Info

Publication number
CN203289074U
CN203289074U CN2013202650772U CN201320265077U CN203289074U CN 203289074 U CN203289074 U CN 203289074U CN 2013202650772 U CN2013202650772 U CN 2013202650772U CN 201320265077 U CN201320265077 U CN 201320265077U CN 203289074 U CN203289074 U CN 203289074U
Authority
CN
China
Prior art keywords
power supply
voltage
output
input
module
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN2013202650772U
Other languages
Chinese (zh)
Inventor
孙曦
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SHENZHEN DIGINET ELECTRONIC Co Ltd
Original Assignee
SHENZHEN DIGINET ELECTRONIC Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SHENZHEN DIGINET ELECTRONIC Co Ltd filed Critical SHENZHEN DIGINET ELECTRONIC Co Ltd
Priority to CN2013202650772U priority Critical patent/CN203289074U/en
Application granted granted Critical
Publication of CN203289074U publication Critical patent/CN203289074U/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Dc-Dc Converters (AREA)

Abstract

The utility model discloses a power supply direct-supply protection circuit and a set-top box. The power supply direct-supply protection circuit comprises a power supply input end, a power output end, a voltage stabilization module and a switch module, wherein the input end of the voltage stabilization module is connected with the input end of a power supply, and the output end of the voltage stabilization module is connected with the trigger end of the switch module; the input end of the switch module is connected with the input end of the power supply, and the output end of the switch module is connected with the output end of the power supply, the trigger end of the switch module is connected with the output end of the voltage stabilization module, wherein the voltage stabilization module is used for outputting a control signal according to a direct-current voltage to control the switch-on and switch-off of the switch module; and the switch module is used for controlling a direct current according to the control signal output by the voltage stabilization module to perform output and switch-off. Therefore, the power supply direct-supply protection circuit and the set-top box disclosed by the utility model are capable of performing direct supply on various MCU (microprogrammed control units) with different voltages, and beneficial to reduce the cost of the circuit.

Description

Power supply direct-furnish protective circuit and set-top box
Technical field
The utility model relates to the electronic circuit technology field, relates in particular to a kind of power supply direct-furnish protective circuit and set-top box.
Background technology
At present, the MCU power supply of most mini high definition set top box is supplied with and is respectively 3.3V, 1.8V, 1V, 5V on the market, general by adopting 12 volts of power supply adaptor power supplies, carry out step-down by the 12V power supply that will input, provide respectively 5V, 3.3V, 1.8V, 1V voltage to supply with MCU, wherein the conversion of 12V-5V and electric current necessarily require 3A,, because circuit is more, cause the hardware circuit cost very high.And directly adopt the power supply of 5V adapter, can reduce 12V and turn the circuit hardware cost of 5V.As everyone knows, the supply voltage that general power supply adaptor is supplied with is subject to itself due to meeting and outside bad border affects, and can produce voltage fluctuation,, if adopt the 5V adapter directly to the MCU power supply of set-top box, just may damage MCU when overtension.
The utility model content
Main purpose of the present utility model is to provide a kind of power supply direct-furnish protective circuit, is intended to realize that the MCU to various different voltages directly powers, to reduce the cost of circuit.
To achieve these goals, the utility model proposes a kind of power supply direct-furnish protective circuit, comprise power input and power output end, Voltage stabilizing module and switch module, the input of described Voltage stabilizing module is connected with power input, and output is connected with the trigger end of switch module; The input of described switch module is connected with power input, and output is connected with power output end, and trigger end is connected with the output of Voltage stabilizing module, wherein,
Described Voltage stabilizing module, be used for conducting and shutoff according to the size output control signal control switch module of input direct voltage;
Described switch module, be used for controlling direct current according to the control signal of Voltage stabilizing module output and export and turn-off.
Preferably, described Voltage stabilizing module comprises the first resistance and voltage-stabiliser tube; One end of described the first resistance is connected with power input, and the other end is connected with the negative electrode of voltage-stabiliser tube; The negative electrode of described voltage-stabiliser tube is connected with an end of the first resistance, plus earth.
Preferably, described Voltage stabilizing module also comprises filter capacitor, and described filter capacitor is connected in the two ends of voltage-stabiliser tube in parallel.
Preferably, described switch module comprises the second resistance, the first switching tube, second switch pipe and the 3rd resistance; One end of described the second resistance is connected with the negative electrode of voltage-stabiliser tube, and the other end is connected with the base stage of the first switching tube; The emitter of described the first switching tube is connected with power input, and base stage is connected with an end of the second resistance, and collector electrode is connected with an end of the 3rd resistance; One end of described the 3rd resistance is connected with the collector electrode of the first switching tube, other end ground connection; The source electrode of described second switch pipe is connected with power input, and grid is connected with the collector electrode of the first switching tube, and drain electrode is connected with power output end.
Preferably, described the first switching tube is the positive-negative-positive triode; Described second switch pipe is field-effect transistor.
The utility model also provides a kind of set-top box, this set-top box comprises power supply direct-furnish protective circuit, this power supply direct-furnish protective circuit comprises power input and power output end, Voltage stabilizing module and switch module, the input of described Voltage stabilizing module is connected with power input, and output is connected with the trigger end of switch module; The input of described switch module is connected with power input, output is connected with power output end, and trigger end is connected with the output of Voltage stabilizing module, wherein, described Voltage stabilizing module, be used for conducting and shutoff according to the size output control signal control switch module of input direct voltage; Described switch module, be used for controlling direct current according to the control signal of Voltage stabilizing module output and export and turn-off.
The utility model is connected input DC power to Voltage stabilizing module and switch module with external power source by power input, the input of described Voltage stabilizing module is connected with power input, output is connected with the trigger end of switch module, and this Voltage stabilizing module is used for conducting and the shutoff according to the size output control signal control switch module of input direct voltage; The input of described switch module is connected with power input, and output is connected with power output end, and trigger end is connected with the output of Voltage stabilizing module, and this switch module is used for controlling DC power supply according to the control signal of Voltage stabilizing module output and exports and turn-off.Therefore, the utility model can be realized the MCU of various different voltages is directly powered, to reduce the cost of circuit.
Description of drawings
Fig. 1 is the circuit structure block diagram of the utility model power supply direct-furnish protective circuit one embodiment;
Fig. 2 is the electrical block diagram of the utility model power supply direct-furnish protective circuit one embodiment.
The realization of the utility model purpose, functional characteristics and advantage, in connection with embodiment, are described further with reference to accompanying drawing.
Embodiment
Further illustrate the technical solution of the utility model below in conjunction with Figure of description and specific embodiment.Should be appreciated that specific embodiment described herein only in order to explain the utility model, and be not used in restriction the utility model.
The utility model proposes a kind of power supply direct-furnish protective circuit.
With reference to Fig. 1 and Fig. 2, Fig. 1 is the circuit structure block diagram of the utility model power supply direct-furnish protective circuit one embodiment; Fig. 2 is the electrical block diagram of the utility model power supply direct-furnish protective circuit one embodiment.
The power supply direct-furnish protective circuit that proposes in the present embodiment; be applied in some important MCU power supply circuits; comprise for the power input that connects power supply and input DC power; be used for connection MCU and the output DC source power output end to MCU; export the conducting of control signal control switch module 10 and the Voltage stabilizing module 20 of shutoff according to the size of input direct voltage, and control direct current according to the control signal of Voltage stabilizing module 20 outputs and export and the switch module 10 that turn-offs.The input of Voltage stabilizing module 20 is connected with power input, and output is connected with the trigger end of switch module 10; Wherein Voltage stabilizing module 20 comprises a voltage-stabiliser tube at least, and this voltage-stabiliser tube, generally according to the size setting of input direct voltage, generally selects the voltage stabilizing value to be slightly larger than the voltage-stabiliser tube of input voltage.The input of above-mentioned switch module 10 is connected with power input, and output is connected with power output end, and trigger end is connected with the output of Voltage stabilizing module 20, and this switch module 10 is in normally off, is used for controlling power supply output; During greater than the voltage stabilizing value of the voltage-stabiliser tube of Voltage stabilizing module 20, the control switch module that transmits control signal 10 power cutoffs, when namely supply voltage is higher, stop power supply output when input direct voltage.
The utility model is connected input DC power to Voltage stabilizing module 20 and switch module 10 with external power source by power input, the input of Voltage stabilizing module 20 is connected with power input, output is connected with the trigger end of switch module 10, and this Voltage stabilizing module 20 is used for conducting and the shutoff according to the size output control signal control switch module 10 of input direct voltage; The input of switch module 10 is connected with power input, output is connected with power output end, trigger end is connected with the output of Voltage stabilizing module 20, and this switch module 10 is used for controlling DC power supply according to the control signal of Voltage stabilizing module 20 outputs and exports and turn-off.Therefore, the utility model can be realized the MCU of various different voltages is directly powered, to reduce the cost of circuit.
Particularly, above-mentioned Voltage stabilizing module 20 comprises the first resistance R 1 and voltage-stabiliser tube Z1; One end of the first resistance R 1 is connected with power input, and the other end is connected with the negative electrode of voltage-stabiliser tube Z1; The negative electrode of voltage-stabiliser tube Z1 is connected with an end of the first resistance R 1, plus earth.Wherein, the voltage stabilizing value of voltage-stabiliser tube Z1 has different voltage amplitudes, therefore, can utilize the difference of the voltage stabilizing value of voltage-stabiliser tube Z1 to realize the MCU of various voltage amplitudes is carried out power supply protection.
Further, Voltage stabilizing module 20 also comprises filter capacitor C1, and filter capacitor C1 is connected in the two ends of voltage-stabiliser tube Z1 in parallel.This filter capacitor C1 carries out filtering to input dc power, makes further output voltage stabilization.
Above-mentioned switch module 10 comprises the second resistance R 2, the first switching tube Q1, second switch pipe Q2 and the 3rd resistance R 3; One end of the second resistance R 2 is connected with the negative electrode of voltage-stabiliser tube Z1, and the other end is connected with the base stage of the first switching tube Q1; The emitter of the first switching tube Q1 is connected with power input, and base stage is connected with an end of the second resistance R 2, and collector electrode is connected with an end of the 3rd resistance R 3; One end of the 3rd resistance R 3 is connected with the collector electrode of the first switching tube Q1, other end ground connection; The source electrode of second switch pipe Q2 is connected with power input, and grid is connected with the collector electrode of the first switching tube Q1, and drain electrode is connected with power output end.Preferably, the first switching tube Q1 is the positive-negative-positive triode; Second switch pipe Q2 is field-effect transistor.Wherein, field-effect transistor belongs to the voltage-controlled type semiconductor device, has that input resistance high (108~109 Ω), noise are little, low in energy consumption, dynamic range large, it is integrated to be easy to, there is no the advantages such as secondary-breakdown phenomenon, safety operation area field width.
With reference to Fig. 1 and Fig. 2, the concrete principle of the utility model power supply direct-furnish protective circuit is achieved as follows:
The MCU that in this circuit, design 5V DC power supply is 5V by power supply direct-furnish protective circuit to a rated voltage powers, and the voltage stabilizing value of the voltage-stabiliser tube Z1 that wherein adopts is 5.1V.When the 5V DC power supply is inputted from power input, the first switching tube Q1 conducting, and then trigger second switch pipe Q2 conducting, the 5V DC power supply is from the source electrode input of second switch pipe Q2, and from drain electrode, export power output end to, thus realize directly to MCU, powering, keep the normal operation of MCU.When mains fluctuations and when input direct voltage during greater than 5.1V; voltage-stabiliser tube Z1 conducting due to reverse breakdown; make the 5V DC power supply of input arrive ground through the first resistance R 1; the first switching tube Q1 is because base earth ends; and then second switch pipe Q2 turn-offs; make power supply not resupply MCU, thereby protection MCU can not be subject to high pressure, do not damage.Wherein filter capacitor C1 can further carry out filtering to the DC power supply of output, makes the supply voltage that exports MCU to more stable.
With reference to Fig. 1 and Fig. 2, the utility model also proposes a kind of set-top box, and this set-top box comprises above-mentioned power supply direct-furnish protective circuit, and the detailed construction of this power supply direct-furnish protective circuit can, with reference to above-described embodiment, not repeat herein., owing to having used above-mentioned power supply direct-furnish protective circuit in set-top box, therefore, when reducing the circuit hardware cost of set-top box, be conducive to guarantee the power supply input safety of set-top box.
The foregoing is only preferred embodiment of the present utility model, not thereby limit the scope of the claims of the present utility model, every equivalent structure or equivalent flow process conversion that utilizes the utility model specification and accompanying drawing content to do, or directly or indirectly be used in other relevant technical fields, all in like manner be included in patent control range of the present utility model.

Claims (6)

1. a power supply direct-furnish protective circuit, comprise power input and power output end, it is characterized in that, also comprises Voltage stabilizing module and switch module; The input of described Voltage stabilizing module is connected with power input, and output is connected with the trigger end of switch module; The input of described switch module is connected with power input, and output is connected with power output end, and trigger end is connected with the output of Voltage stabilizing module, wherein,
Described Voltage stabilizing module, be used for conducting and shutoff according to the size output control signal control switch module of input direct voltage;
Described switch module, be used for controlling direct current according to the control signal of Voltage stabilizing module output and export or disconnect.
2. power supply direct-furnish protective circuit according to claim 1, is characterized in that, described Voltage stabilizing module comprises the first resistance and voltage-stabiliser tube; One end of described the first resistance is connected with power input, and the other end is connected with the negative electrode of voltage-stabiliser tube; The negative electrode of described voltage-stabiliser tube is connected with an end of the first resistance, plus earth.
3. power supply direct-furnish protective circuit according to claim 2, is characterized in that, described Voltage stabilizing module also comprises filter capacitor, and described filter capacitor is connected in the two ends of voltage-stabiliser tube in parallel.
4. power supply direct-furnish protective circuit according to claim 1, is characterized in that, described switch module comprises the second resistance, the first switching tube, second switch pipe and the 3rd resistance; One end of described the second resistance is connected with the negative electrode of voltage-stabiliser tube, and the other end is connected with the base stage of the first switching tube; The emitter of described the first switching tube is connected with power input, and base stage is connected with an end of the second resistance, and collector electrode is connected with an end of the 3rd resistance; One end of described the 3rd resistance is connected with the collector electrode of the first switching tube, other end ground connection; The source electrode of described second switch pipe is connected with power input, and grid is connected with the collector electrode of the first switching tube, and drain electrode is connected with power output end.
5. power supply direct-furnish protective circuit according to claim 1, is characterized in that, described the first switching tube is the positive-negative-positive triode; Described second switch pipe is field-effect transistor.
6. a set-top box, is characterized in that, comprises the described power supply direct-furnish of claim 1-5 any one protective circuit.
CN2013202650772U 2013-05-15 2013-05-15 Power supply direct-supply protection circuit and set-top box Expired - Fee Related CN203289074U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2013202650772U CN203289074U (en) 2013-05-15 2013-05-15 Power supply direct-supply protection circuit and set-top box

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2013202650772U CN203289074U (en) 2013-05-15 2013-05-15 Power supply direct-supply protection circuit and set-top box

Publications (1)

Publication Number Publication Date
CN203289074U true CN203289074U (en) 2013-11-13

Family

ID=49545418

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2013202650772U Expired - Fee Related CN203289074U (en) 2013-05-15 2013-05-15 Power supply direct-supply protection circuit and set-top box

Country Status (1)

Country Link
CN (1) CN203289074U (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106560958A (en) * 2016-10-20 2017-04-12 金卡高科技股份有限公司 Low-power-consumption voltage protection circuit and gas meter
CN106786353A (en) * 2016-12-13 2017-05-31 京信通信技术(广州)有限公司 A kind of overvoltage crowbar
CN108599124A (en) * 2018-05-03 2018-09-28 北京市科通电子继电器总厂有限公司 Control circuit, system and the integrated circuit of switching device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106560958A (en) * 2016-10-20 2017-04-12 金卡高科技股份有限公司 Low-power-consumption voltage protection circuit and gas meter
CN106786353A (en) * 2016-12-13 2017-05-31 京信通信技术(广州)有限公司 A kind of overvoltage crowbar
CN108599124A (en) * 2018-05-03 2018-09-28 北京市科通电子继电器总厂有限公司 Control circuit, system and the integrated circuit of switching device
CN108599124B (en) * 2018-05-03 2019-11-26 北京市科通电子继电器总厂有限公司 Control circuit, system and the integrated circuit of switching device

Similar Documents

Publication Publication Date Title
CN203301611U (en) Direct-current switching circuit and switching power source
CN203289074U (en) Power supply direct-supply protection circuit and set-top box
CN204028740U (en) A kind of current foldback circuit that is applied to LDO
CN202043053U (en) Switching power supply with under-voltage protection function
CN206807283U (en) A kind of start-up circuit of Switching Power Supply
CN201039001Y (en) A standby circuit for switch power
CN203104307U (en) Controllable common ground power supply circuit
CN104679214A (en) Voltage regulating circuit
CN202094845U (en) Device for managing power supply
CN205750611U (en) A kind of regulator control circuit
CN103902009A (en) Discharge circuit
WO2016161746A1 (en) Power supply circuit and power supply method
CN203206380U (en) Starting control circuit, display panel driving circuit and display apparatus
CN201467324U (en) Low power consumption CPU standby commutation circuit
CN203014675U (en) Buck-boost switching power supply and controller thereof
CN102570789A (en) High-voltage starting circuit
CN207283402U (en) ON-OFF control circuit
CN207166838U (en) A kind of backlight constant current drive circuit
CN206004528U (en) A kind of high power booster circuit
CN201153295Y (en) Television standby detection power supply circuit
CN108923500A (en) A kind of switched charge chip and electronic equipment
CN204886132U (en) Prevent voltage pulse circuit
CN203967980U (en) Switching power circuit and supply unit
CN204615684U (en) The power module of three-phase alternating current input and air conditioner
CN204425182U (en) Single tube pfc circuit and power module

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20131113

Termination date: 20170515

CF01 Termination of patent right due to non-payment of annual fee