CN203350420U - Battery voltage monitoring circuit for battery powered equipment - Google Patents

Battery voltage monitoring circuit for battery powered equipment Download PDF

Info

Publication number
CN203350420U
CN203350420U CN 201320374658 CN201320374658U CN203350420U CN 203350420 U CN203350420 U CN 203350420U CN 201320374658 CN201320374658 CN 201320374658 CN 201320374658 U CN201320374658 U CN 201320374658U CN 203350420 U CN203350420 U CN 203350420U
Authority
CN
China
Prior art keywords
resistance
battery
circuit
microprocessor
converter
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
CN 201320374658
Other languages
Chinese (zh)
Inventor
刘守宁
杨欣
孟庆坤
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.)
Tianjin Chengke Automation Engineering & Technology Co Ltd
Original Assignee
Tianjin Chengke Automation Engineering & Technology 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 Tianjin Chengke Automation Engineering & Technology Co Ltd filed Critical Tianjin Chengke Automation Engineering & Technology Co Ltd
Priority to CN 201320374658 priority Critical patent/CN203350420U/en
Application granted granted Critical
Publication of CN203350420U publication Critical patent/CN203350420U/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The utility model provides a battery voltage monitoring circuit for battery powered equipment. The battery voltage monitoring circuit comprises a bleeder circuit which is formed by serially connecting a first resistor (R1) and a second resistor (R2), and a microprocessor (MCU). The connected ends of the first resistor (R1) and the second resistor (R2) are further connected with an AD converter input pin (P0_6) of the microprocessor (MCU). The battery voltage monitoring circuit is characterized in that an electronic switch is further connected between the battery voltage input end (Vin) of the equipment and the bleeder circuit, wherein the on/off of the electronic switch is controlled a control end (P2_0) of the microprocessor (MCU). The battery voltage monitoring circuit is especially suitable for situations in which the input internal resistance of the AD converter is uncertain. The circuit of the utility model not only can be used to reduce the influences of the input internal resistance of the AD converter, and but also can be used to further reduce the meaningless power consumption of the battery voltage detection circuit on the battery level, and reduce the influences on the service life of a battery. Moreover, the circuit has advantages of simple design, good accuracy degree, low power consumption and low cost, and especially suitable for being used on equipment having sensitive equipment cost.

Description

A kind of battery voltage supervisory circuit for battery supply set
Technical field
The utility model belongs to the battery supply set field, especially relates to a kind of circuit that carries out electric quantity monitoring for the battery to battery supply set.
Background technology
Along with scientific and technological development and progress, the wireless communication technology level is greatly improved, and in civilian, commercialization and industrial circle, application is very widely arranged.The quantity of Wireless Telecom Equipment is very large, and if the equipment of employing wireless communication technology still adopts wired mode to be powered, bring very large inconvenience on the one hand installation, debugging, use and the daily servicing of equipment, also can't embody on the other hand the technical advantage of wireless device.Therefore adopt battery powered wireless device convenient when reality is used, number of devices is also more many.
Owing to adopting battery to be powered, the electric weight of battery is limited, so be also limited the serviceable life of equipment.Must carry out Real-Time Monitoring to battery electric quantity, send indicator signal when battery electric quantity runs low, the prompting user changes in time battery or is battery charging, in order to avoid battery electric quantity causes equipment not work while exhausting, impact is use normally.
So far, various monitoring cell electricity quantity means are a lot, and technology is comparative maturity also, is mainly following two schemes:
A kind of is to utilize special-purpose battery electric quantity to measure chip to monitor battery electric quantity.This scheme is used simple, and precision is also higher, but, owing to having adopted special-purpose chip, cost compare is high.Many in wireless device quantity, and equipment cost not too is applicable to using than more sensitive occasion.
Another kind is to adopt the AD converter of wireless device microprocessor self to be measured cell voltage, by cell voltage, judges battery electric quantity.The method implements fairly simple, and with low cost, is applicable to very much the application scenario of large number quipments.But, due to the restriction of AD converter, the voltage of the battery detected can not be greater than the operating voltage of microprocessor self, needs are measured after adopting bleeder circuit to the cell voltage dividing potential drop again.Due to the existence of bleeder circuit, the low power capabilities of equipment and the precision of battery voltage measurement have all been brought to very large impact.
This patent circuit is mainly the problem that solves the first scheme existence and is designed.
Above-mentioned the second adopts bleeder circuit to carry out in the implementation of battery voltage measurement, measuring principle figure as shown in Figure 1, in figure, the cell voltage input end that Vin is equipment, R1 and R2 form resistor voltage divider circuit.Voltage Vad after the dividing potential drop AD converter inner with microprocessor (MCU) is connected, and by AD converter, carries out the voltage transitions measurement, finally by Vad, calculates cell voltage Vin.Ideally, the voltage Vad after dividing potential drop is:
V ad = R 1 R 1 + R 2 V in Formula 1
In the situation that R1 and R2 resistance are fixing, the proportionate relationship between Vad and Vin is fixed, and can calculate very simply cell voltage Vin by above-mentioned formula 1, and accuracy is also higher.
But during actual the use, there is the input internal resistance in AD converter, due to the input internal resistance existence, the equivalent schematic diagram of above-mentioned change-over circuit as shown in Figure 2: the input internal resistance of AD converter is equivalent to resistance R 3, and the proportionate relationship of the voltage Vad after cell voltage Vin and dividing potential drop becomes like this
V ad = R 1 R 1 + R 2 × R 3 R 2 + R 3 V in Formula 2
Due to the existence of equivalent internal resistance R3, and the input internal resistance of the AD converter of different manufacturers, different model is also not exclusively the same, and otherness is large especially.Even adopt the AD converter of same model, when environment for use changes (as working temperature changes), the resistance of input internal resistance R3 also can change.Therefore the proportionate relationship of Vin and Vad, with regard to more complicated, is calculated by above-mentioned formula 2 accuracy that is difficult to the assurance battery voltage measurement simply.
Summary of the invention
For the problem of above-mentioned existence, this patent provides a kind of battery voltage supervisory circuit, is particularly suitable for the uncertain situation of above-mentioned AD converter input internal resistance.This patent circuit not only can reduce the impact of AD converter input internal resistance, can also further reduce the unnecessary consumption of battery voltage detection circuit to battery electric quantity, reduces the impact on the serviceable life of battery.
For solving the problems of the technologies described above, the technical solution adopted in the utility model is: a kind of battery voltage supervisory circuit for battery supply set, comprise the bleeder circuit and the microprocessor (MCU) that are composed in series by the first resistance (R1) and the second resistance (R2), the first resistance (R1) also is connected with the AD converter input pin (P0_6) of microprocessor (MCU) with the connected end of the second resistance (R2), it is characterized in that, also be connected with an electronic switch between the cell voltage input end (Vin) of equipment and bleeder circuit, the on off state of electronic switch is controlled by the control end (P2_0) of microprocessor (MCU).
Further, described electronic switch comprises positive-negative-positive triode (Q1), NPN type triode (Q2), the 4th resistance (R4), the 5th resistance (R5), the 6th resistance (R6) and the 7th resistance (R7), the cell voltage input end (Vin) of equipment is connected with the 5th resistance (R5) end with the emitter of positive-negative-positive triode (Q1), the base stage of positive-negative-positive triode (Q1) is connected with the 4th resistance (R4) end, and the 4th resistance (R4) is connected with the collector of NPN type triode (Q2) with the other end of the 5th resistance (R5); The base stage of NPN type triode (Q2) is connected with the 7th resistance (R7) end with the 6th resistance (R6), the other end ground connection of the 6th resistance (R6), the grounded emitter of NPN type triode (Q2), the control end (P2_0) of another termination microprocessor of the 7th resistance (R7); The collector of positive-negative-positive triode (Q1) is connected with the input end of first resistance (R1) of bleeder circuit, and the other end of the first resistance (R1) is connected with the second resistance (R2) end, the other end ground connection of the second resistance (R2); The first resistance (R1) with the second resistance (R2), be connected the part voltage be the voltage (Vad) after the cell voltage dividing potential drop, be connected to the AD converter input pin (P0_6) of microprocessor.
Further, the input internal resistance (R3) of the AD converter of the resistance value of the first resistance (R1) and the second resistance (R2) and microprocessor differs at least two orders of magnitude.
The utility model also provides another kind of solution, it is a kind of battery voltage supervisory circuit for battery supply set, comprise the bleeder circuit and the microprocessor (MCU) that are composed in series by the first resistance (R1) and the second resistance (R2), the cell voltage input end (Vin) of equipment is connected with the input end of first resistance (R1) of bleeder circuit, the other end of the first resistance (R1) is connected with the second resistance (R2) end, the other end ground connection of the second resistance (R2); It is characterized in that, be connected with the second resistance (R2) voltage of part of the first resistance (R1) is the voltage (Vad) after the cell voltage dividing potential drop, between the AD converter input pin (P0_6) of itself and microprocessor, also is connected with a signal isolator.
Further, described signal isolator is an operational amplifier chip.
Advantage and the good effect that the utlity model has are: be particularly suitable for the uncertain situation of above-mentioned AD converter input internal resistance.This patent circuit not only can reduce the impact of AD converter input internal resistance, can also further reduce the unnecessary consumption of battery voltage detection circuit to battery electric quantity, reduces the impact on the serviceable life of battery.Circuit design is simple, accuracy is high, power consumption is little, with low cost.Be particularly suitable for being used in to equipment cost than on more sensitive equipment.
The accompanying drawing explanation
Fig. 1 and Fig. 2 are that prior art adopts bleeder circuit to carry out the battery voltage measurement circuit schematic diagram
Fig. 3 adopts the battery voltage measurement circuit schematic diagram of setting up electronic switch
Fig. 4 is a kind of particular circuit configurations schematic diagram of electronic switch
Fig. 5 adopts the battery voltage measurement circuit schematic diagram of setting up signal isolator
In figure:
Embodiment
As shown in Figure 3, in battery voltage measurement circuit of the present utility model, increased an electronic switch between bleeder circuit and cell voltage input end.
The on off state of electronic switch is controlled by the Set pin of microprocessor (MCU), carries out cell voltage when conversion, opens electronic switch, and cell voltage is measured by AD converter after by the bleeder circuit dividing potential drop.
After the cell voltage conversion, close electronic switch, the bleeder circuit that R1 and R2 form is the consuming cells electric weight no longer.
Owing to having added the electronic switch mentality of designing, only when battery voltage detection, bleeder circuit R1 and R2 just can have consumption to battery electric quantity, and this detection time is shorter, with respect to the working time of equipment, can ignore, battery voltage measurement circuit also can be ignored to the consumption of battery electric quantity.
Simultaneously, in this circuit, the input internal resistance R3 of the resistance value of resistance R 1 and R2 and AD converter differs at least two orders of magnitude, be that resistance R 3 is much larger than resistance R 2, bleeder circuit can be ignored the existence of AD converter input internal resistance R3 like this, proportionate relationship between Vin and Vad can be formula 1 by formula 2 abbreviations, and the proportionate relationship of Vin and Vad is calculated according to formula 1.Resistance R 1 and R2 exist owing to being independent of microprocessor, therefore, when components selection, can select the reasonable components and parts of technical parameter, guarantee the accuracy of battery voltage measurement.
The electronic switch of realizing above-mentioned functions can have multiple concrete form, and the applicant provides wherein a kind of particular circuit configurations, and as shown in Figure 4: Vin is cell voltage, and resistance R 1 and R2 form bleeder circuit.Triode Q1 and Q2, and resistance R 4, R5, R6 and R7 composition electronic switch, wherein triode Q1 is the positive-negative-positive triode, Q2 is NPN type triode.Cell voltage Vin is connected with resistance R 5 with the emitter of triode Q1, and the base stage of Q1 is connected with resistance R 4, and resistance R 4 is connected with the other end of resistance R 5 and the collector of Q2; The base stage of Q2 is connected with R7 with resistance R 6, the other end ground connection of R6, the grounded emitter of Q2, the control end of another termination microprocessor of resistance R 7 (P2_0, i.e. above-mentioned Set pin); The collector of Q1 is connected with resistance R 1, and the other end of R1 is connected with resistance R 2, the other end ground connection of R2.Resistance R 1 with R2, be connected the part voltage be the voltage Vad after the cell voltage dividing potential drop, be connected to the AD converter input pin (P0_6) of microprocessor.
Principle of work is as follows:
While carrying out battery voltage measurement, microprocessor pin P2_0 exports high level, triode Q2 conducting, and then triode Q1 conducting, after triode Q1 conducting, the pressure drop of emitter and inter-collector is ignored, and cell voltage Vin is added on the bleeder circuit of resistance R 1 and R2 composition.Because the resistance of R1 and R2 is smaller, therefore can ignore the impact of the input internal resistance of AD converter, the voltage Vad that in microprocessor, AD converter converts and the proportionate relationship of Vin are calculated according to formula 1.
After battery voltage measurement, microprocessor pin P2_0 input low level, not conducting of triode Q2, and then also not conducting of triode Q1, it is upper that cell voltage Vin can not be added in resistance R 1 and R2, thereby avoided the consumption of battery electric quantity.
In addition, because the input internal resistance of AD converter is generally larger, be generally hundreds of K ohm, therefore for the problems referred to above, a kind of simple solution is to reduce the resistance of R1 and R2 in the application circuit of Fig. 2, as a few K ohm, makes the resistance of R1, R2 and R3 differ two orders of magnitude, proportionate relationship between Vin and Vad can be formula 1 by formula 2 Approximate Equivalent, reaches the purpose of Measurement accuracy cell voltage.But from metering circuit, can find out, R1 and R2 resistance are all the time at the consuming cells electric weight, and too low resistance can make electric quantity consumption very large, and battery can reduce greatly, brings more serious problem.
Therefore, the applicant also provides another kind of solution, as shown in Figure 5: between the bleeder circuit of battery voltage detection circuit and AD converter, added a signal isolator.This signal isolator is generally the operational amplifier chip, the input internal resistance infinity of its equivalence, the output internal resistance infinitesimal of equivalence.Therefore the resistance value of resistance R 1 and R2 can be very large, and the voltage Vad after dividing potential drop equates with the voltage Vad2 after signal isolator.The voltage Vad2 that AD converter is changed like this is the voltage Vad after the Vin dividing potential drop, with the comparison of cell voltage Vin, according to formula 1, is calculated.Because the resistance value of resistance R 1 and R2 can be very large, therefore very little to the consumption of battery electric quantity.
Although this scheme can reach the same effect that realizes, but still has the following disadvantages:
The signal isolator adopted is generally operational amplifier, is special-purpose chip, and than common triode, resistance, cost compare is high.
Owing to there is no electronic switch, although resistance R 1 and R2 value are larger, smaller to the consumption of battery electric quantity, this consumption exists always, therefore to the consumption of battery electric quantity, can not ignore fully, to still having a certain impact in serviceable life of equipment.

Claims (2)

1. the battery voltage supervisory circuit for battery supply set, comprise the bleeder circuit and the microprocessor (MCU) that are composed in series by the first resistance (R1) and the second resistance (R2), the first resistance (R1) also is connected with the AD converter input pin (P0_6) of microprocessor (MCU) with the connected end of the second resistance (R2), it is characterized in that, also be connected with an electronic switch between the cell voltage input end (Vin) of equipment and bleeder circuit, the on off state of electronic switch is controlled by the control end (P2_0) of microprocessor (MCU);
Described electronic switch comprises positive-negative-positive triode (Q1), NPN type triode (Q2), the 4th resistance (R4), the 5th resistance (R5), the 6th resistance (R6) and the 7th resistance (R7), the cell voltage input end (Vin) of equipment is connected with the 5th resistance (R5) end with the emitter of positive-negative-positive triode (Q1), the base stage of positive-negative-positive triode (Q1) is connected with the 4th resistance (R4) end, and the 4th resistance (R4) is connected with the collector of NPN type triode (Q2) with the other end of the 5th resistance (R5); The base stage of NPN type triode (Q2) is connected with the 7th resistance (R7) end with the 6th resistance (R6), the other end ground connection of the 6th resistance (R6), the grounded emitter of NPN type triode (Q2), the control end (P2_0) of another termination microprocessor of the 7th resistance (R7); The collector of positive-negative-positive triode (Q1) is connected with the input end of first resistance (R1) of bleeder circuit, and the other end of the first resistance (R1) is connected with the second resistance (R2) end, the other end ground connection of the second resistance (R2); The first resistance (R1) with the second resistance (R2), be connected the part voltage be the voltage (Vad) after the cell voltage dividing potential drop, be connected to the AD converter input pin (P0_6) of microprocessor.
2. battery voltage supervisory circuit according to claim 1, it is characterized in that: the input internal resistance (R3) of the resistance value of the first resistance (R1) and the second resistance (R2) and the AD converter of microprocessor differs at least two orders of magnitude.
CN 201320374658 2013-06-26 2013-06-26 Battery voltage monitoring circuit for battery powered equipment Expired - Fee Related CN203350420U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201320374658 CN203350420U (en) 2013-06-26 2013-06-26 Battery voltage monitoring circuit for battery powered equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 201320374658 CN203350420U (en) 2013-06-26 2013-06-26 Battery voltage monitoring circuit for battery powered equipment

Publications (1)

Publication Number Publication Date
CN203350420U true CN203350420U (en) 2013-12-18

Family

ID=49750302

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 201320374658 Expired - Fee Related CN203350420U (en) 2013-06-26 2013-06-26 Battery voltage monitoring circuit for battery powered equipment

Country Status (1)

Country Link
CN (1) CN203350420U (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103344822A (en) * 2013-06-26 2013-10-09 天津成科自动化工程技术有限公司 Battery voltage monitoring circuit used for battery powered equipment
CN110912105A (en) * 2019-10-25 2020-03-24 芜湖宏景电子股份有限公司 High-low voltage protection circuit for power supply voltage range detection

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103344822A (en) * 2013-06-26 2013-10-09 天津成科自动化工程技术有限公司 Battery voltage monitoring circuit used for battery powered equipment
CN110912105A (en) * 2019-10-25 2020-03-24 芜湖宏景电子股份有限公司 High-low voltage protection circuit for power supply voltage range detection

Similar Documents

Publication Publication Date Title
CN103344822A (en) Battery voltage monitoring circuit used for battery powered equipment
CN102590609B (en) The method of mobile terminal and measurement mobile terminal power consumption
CN103901345A (en) Storage battery electric quantity detection apparatus and method
CN104458045A (en) Temperature measuring system
CN203490345U (en) Simple battery electric quantity measuring circuit based on analog comparator
CN203350420U (en) Battery voltage monitoring circuit for battery powered equipment
CN203773034U (en) Testing device of direct-current ripple system
CN103471654A (en) Self-power-supply water flow monitoring system
CN205139344U (en) Power display device and electronic equipment
CN201311485Y (en) Ripple factor detecting device adapted to DC power supply
CN103698691B (en) Electric car bridge board automatic testing calibration method
CN203519712U (en) Battery voltage acquisition system
CN204206279U (en) A kind of standby power consumption of mobile phone test circuit
CN203310979U (en) Battery voltage monitoring circuit for battery-powered device
CN203084092U (en) Intelligentized solar charge and discharge regulating instrument
CN201955394U (en) Air-conditioning power consumption metering and display device
CN202793423U (en) Platinum resistance and analog current transmitting circuit
CN112130093A (en) Wire aligning detection device for realizing wire-disconnecting-free test by utilizing linear Hall sensor
CN102879742A (en) Battery electric quantity detection circuit
CN102680121A (en) Intelligent indoor temperature acquirer
CN105023412A (en) Sensor signal collection device
CN201773149U (en) Real-time online detection device for series voltage source
CN102207517B (en) Method for testing mean current of circuits by Farad capacitor
CN202057776U (en) Passive liquid crystal display (LCD) constant-current electronic load
CN102749591A (en) Passive LCD (liquid crystal display) display type constant-current electronic load

Legal Events

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

Granted publication date: 20131218

Termination date: 20150626

EXPY Termination of patent right or utility model