CN204046414U

CN204046414U - Turned off automatic control type PWM ripple for gas sensor controls power circuit

Info

Publication number: CN204046414U
Application number: CN201420373314.1U
Authority: CN
Inventors: 任春红; 步东伟; 李敬波; 李晓辉; 高伟峰; 聂山权; 周鹏
Original assignee: ZHENGZHOU CHUANGWEI MEIAN TECHNOLOGY CO LTD
Current assignee: Henan Hanwei Electronics Co Ltd
Priority date: 2014-07-08
Filing date: 2014-07-08
Publication date: 2014-12-24
Anticipated expiration: 2024-07-08

Abstract

The utility model discloses a kind of turned off automatic control type for gas sensor PWM ripple and control power circuit, wherein, comprise can switch off control circuit, PWM wave generation circuit and burning voltage output circuit; Can switch off control circuit and comprise resistance R5, R6 and NMOS tube T2, one end of resistance R5 connects externally fed power positive end V1, the other end is connected with the grid of NMOS tube T2 through resistance R6, the source electrode of NMOS tube T2 meets GND, drain electrode connects the resistance R4 of PWM wave generation circuit and the grid of NMOS tube T1 respectively, and outside can output respectively connecting resistance R5 and R6 of cut-off signals P1; Described resistance R5 is pull-up resistor.This power circuit of the utility model uses less discrete component, achieve the stable power-supplying to gas sensor, this circuit is simple, reliable and stable, components and parts are few, cost is low, and the equipment cost using this utility model is decreased, and is convenient to marketing and utilizes.

Description

Turned off automatic control type PWM ripple for gas sensor controls power circuit

Technical field

The utility model relates to a kind of power supply circuit of gas sensor, especially relates to a kind of turned off automatic control type for gas sensor PWM ripple and controls power circuit.

Background technology

Along with the development of science and technology, the raising of human living standard, people to the requirement of its surrounding environment also in continuous raising, people's special concern affects inherently safe gas, such as methane, the inflammable harm gas such as sulfur dioxide, there is all kinds of gas detect portable equipment for this reason, this kind equipment price general charged is cheaper, such as, ambient methane tester, various mining portable methane tester, all kinds of mining sulfur dioxide tester, etc., the precision of this kind of portable gas detection equipment and sensitivity mainly rely on the characteristic of gas sensor, and the power pack of gas sensor is the key factor making the reliable and stable operation of gas sensor, for this reason, lot of domestic and international experts and scholars propose different gas sensor power supply methods, comprise use high-precision regulated power supply, but its cost is too high, more difficultly to promote on environment measuring field and colliery, particularly some technical conditions and the relatively backward little ore deposit of economic situation, also the scheme proposing to use high Precision Processing chip is had, but there is the high problem of cost equally in the program, the equipment making to be suitable for its method is more difficult to be promoted on market, colliery.

Utility model content

In view of this, the purpose of this utility model is to provide a kind of turned off automatic control type for gas sensor PWM ripple to control power circuit, this circuit uses less discrete component, circuit simple and stable, effectively raise the stability, the reliability that are suitable for equipment of the present utility model, reduce the cost of corresponding gas detection alarm device.

For achieving the above object, the utility model by the following technical solutions:

Turned off automatic control type PWM ripple for gas sensor controls a power circuit, wherein, comprise can switch off control circuit, PWM wave generation circuit and burning voltage output circuit; Can switch off control circuit and comprise resistance R5, R6 and NMOS tube T2, one end of resistance R5 connects externally fed power positive end V1, the other end is connected with the grid of NMOS tube T2 through resistance R6, the source electrode of NMOS tube T2 meets GND, drain electrode connects the resistance R4 of PWM wave generation circuit and the grid of NMOS tube T1 respectively, and outside can output respectively connecting resistance R5 and R6 of cut-off signals P1; Described resistance R5 is pull-up resistor;

PWM wave generation circuit comprises resistance R1, R2, R3, R4, R7, NMOS tube T1 and integrated chip U5A; Described resistance R1 mono-termination sensor power power positive end V2, resistance R1, R2, R3 connect successively, and resistance R3 meets GND; Negative input end 2 connecting resistance R2, R3 respectively of integrated chip U5A, positive input terminal 3 meets external reference voltage a reference source VR1, one end of output 1 connecting resistance R4; The resistance R4 other end connects the drain electrode of NMOS tube T2 and the grid of NMOS tube T1 respectively, and the drain electrode of NMOS tube T1 connects the input of burning voltage output circuit, one end of source electrode connecting resistance R7, another termination GND of resistance R7; Sensor power power supply negative terminal and externally fed power supply negative terminal share, and are GND.

As preferably, described burning voltage output circuit comprises triode T3 and electric capacity C4, and the base stage of triode T3 connects the drain electrode of PWM wave generation circuit NMOS tube T1, and emitter meets externally fed power positive end V1, collector electrode meets another termination GND of electric capacity C4 and sensor power power positive end V2, electric capacity C4.

As preferably, described NMOS tube T1, T2, T3 are NMOS tube 2SK160.

As preferably, described integrated chip U5A adopts LM324 chip.

As preferably, described electric capacity C4 is electrochemical capacitor.

The beneficial effects of the utility model are:

The utility model utilizes less discrete component, realize the stable power-supplying to gas sensor, employing can turn off control, can the power supply of manual control gas sensor and shutoff, automatic control type PWM ripple is used to control, the output voltage of the utility model power circuit can be made highly stable, make the operation that gas sensor is more reliable and stable, and this circuit is simple, make to use stabilization of equipment performance of the present utility model and reliability all very high, reduce the cost using equipment of the present utility model, be convenient to the marketing and the application that improve use equipment of the present utility model.

Other advantages of the present utility model, target and feature will be set forth to a certain extent in the following description, and to a certain extent, based on will be apparent to those skilled in the art to investigating hereafter, or can be instructed from practice of the present utility model.Target of the present utility model and other advantages can be realized by structure specifically noted in specification below or accompanying drawing and be obtained.

Accompanying drawing explanation

Fig. 1 is circuit theory diagrams of the present utility model;

Fig. 2 is the figure that switches off control circuit of the present utility model;

Fig. 3 is automatic control type PWM wave generation circuit figure of the present utility model;

Fig. 4 is burning voltage output circuit figure of the present utility model;

Fig. 5 is the concrete implementing circuit figure of one of the present utility model.

Embodiment

Below in conjunction with drawings and Examples, the utility model is further described.

As shown in Figure 1, the utility model comprise can switch off control circuit, PWM wave generation circuit and burning voltage output circuit.V1 is externally fed power positive end, GND is externally fed power supply negative terminal, P1 is that outside can cut-off signals, P1 can connect single-chip microcomputer pin or button, VC is the turned off control signal that P1 produces, V2 is the sensor power power positive end signal that we need, and sensor power power supply negative terminal and externally fed power supply negative terminal share, and are GND.VR1 is external reference voltage a reference source, and VR2 is the automatic control type control signal of stable V2, and VA is PWM wave control signal, and VB is automatic control type PWM wave output signal.

Operation principle of the present utility model is, button or single-chip microcomputer pin P1 press, and T2 turns off, and VR1 is greater than VR2, VA is high level, T1 conducting, VB is low level, T3 conducting, V2 starts power supply, when V2 is greater than our setting voltage value, VR1 is less than VR2, and final T3 is turned off, V2 uses C4 to power, voltage drop, when voltage drop is to the minimum zone of our set point, VR1 is greater than VR2, make T3 conducting, to C4 charging, export V2 simultaneously and power to gas sensor, thus complete certainly controlling of PWM ripple output.

As shown in Figure 2, can switch off control circuit and comprise resistance R5, R6 and NMOS tube T2, one end of resistance R5 connects externally fed power positive end V1, the other end is connected with the grid of NMOS tube T2 through resistance R6, the source electrode of NMOS tube T2 meets GND, drain electrode connects the resistance R4 of PWM wave generation circuit and the grid of NMOS tube T1 respectively, and outside can output respectively connecting resistance R5 and R6 of cut-off signals P1.Resistance R5 is pull-up resistor, is high level under making P1 normal operation, R6 and T2 composition control switch, and VC is control switch output signal, controls operation and the shutoff of the utility model power circuit.

As shown in Figure 3, PWM wave generation circuit comprises resistance R1, R2, R3, R4, R7, NMOS tube T1 and integrated chip U5A; Resistance R1 mono-termination sensor power power positive end V2, resistance R1, R2, R3 connect successively, and resistance R3 meets GND; Negative input end 2 connecting resistance R2, R3 respectively of integrated chip U5A, positive input terminal 3 meets external reference voltage a reference source VR1, one end of output 1 connecting resistance R4; The resistance R4 other end connects the drain electrode of NMOS tube T2 and the grid of NMOS tube T1 respectively, and the drain electrode of NMOS tube T1 connects the input of burning voltage output circuit, one end of source electrode connecting resistance R7, another termination GND of resistance R7; Sensor power power supply negative terminal and externally fed power supply negative terminal share, and are GND.

VR1 is external reference voltage a reference source, R1, R2, R3 form the bleeder circuit of power supply signal V2, this bleeder circuit produces automatic control type control signal VR2, for the duty ratio of FEEDBACK CONTROL automatic control type PWM ripple, thus stablize out-put supply signal V2, R4, T1 form automatic control type PWM ripple output switch circuit, and export the automatic control type PWM ripple signal that we need, VC is the above-mentioned output signal turning off control section.

As shown in Figure 4, burning voltage output circuit comprises triode T3 and electric capacity C4, and the base stage of triode T3 connects the drain electrode of PWM wave generation circuit NMOS tube T1, and emitter meets externally fed power positive end V1, collector electrode meets another termination GND of electric capacity C4 and sensor power power positive end V2, electric capacity C4.Electric capacity C4 is electrochemical capacitor, and triode T3 performs according to above-mentioned middle VB signal and turns on and off action, and coordinates the discharge and recharge of electric capacity C4 to produce the gas sensor Power supply signal V2 of our needs.

According to description above, and can calculate V2 and V1 according to circuit base knowledge, the relation of VR2 and V2, its pass is , Fig. 5 gives a kind of embody rule circuit of the present utility model, and gives the value of each device, but all devices are not limited thereto value.

As shown in Figure 5, VR1 is 1.2V external reference voltage a reference source, and R1, R2, R3 form the bleeder circuit of power supply signal V2, and U5A is integrated chip LM324, R1 is 10K resistance, and R2 is 20K resistance, and R3 is 22K resistance, R4 is 1K resistance, and R7 is 1K resistance, and T1 is NMOS tube 2SK160.R5 is 10K resistance, and R6 is 1K resistance, and T2 is NMOS tube 2SK16, and wherein, R5 is pull-up resistor.The electrochemical capacitor of T3 to be triode 2SB815, C4 be 10uF/25V.

By description above, can obtain V2 and V1, the relation of VR2 and V2, its pass is .

What finally illustrate is, above embodiment is only in order to illustrate the technical solution of the utility model and unrestricted, other amendments that those of ordinary skill in the art make the technical solution of the utility model or equivalently to replace, only otherwise depart from the spirit and scope of technical solutions of the utility model, all should be encompassed in the middle of right of the present utility model.

Claims

1. the turned off automatic control type PWM ripple for gas sensor controls a power circuit, it is characterized in that: comprise can switch off control circuit, PWM wave generation circuit and burning voltage output circuit; Can switch off control circuit and comprise resistance R5, R6 and NMOS tube T2, one end of resistance R5 connects externally fed power positive end V1, the other end is connected with the grid of NMOS tube T2 through resistance R6, the source electrode of NMOS tube T2 meets GND, drain electrode connects the resistance R4 of PWM wave generation circuit and the grid of NMOS tube T1 respectively, and outside can output respectively connecting resistance R5 and R6 of cut-off signals P1; Described resistance R5 is pull-up resistor;

2. a kind of PWM of the turned off automatic control type for gas sensor ripple according to claim 1 controls power circuit, it is characterized in that: described burning voltage output circuit comprises triode T3 and electric capacity C4, the base stage of triode T3 connects the drain electrode of PWM wave generation circuit NMOS tube T1, emitter meets externally fed power positive end V1, collector electrode meets another termination GND of electric capacity C4 and sensor power power positive end V2, electric capacity C4.

3. a kind of PWM of the turned off automatic control type for gas sensor ripple according to claim 1 and 2 controls power circuit, it is characterized in that: described NMOS tube T1, T2, T3 are NMOS tube 2SK160.

4. a kind of PWM of the turned off automatic control type for gas sensor ripple according to claim 3 controls power circuit, it is characterized in that: described integrated chip U5A adopts LM324 chip.

5. a kind of PWM of the turned off automatic control type for gas sensor ripple according to claim 4 controls power circuit, it is characterized in that: described electric capacity C4 is electrochemical capacitor.