CN112198442A - Battery electric quantity detection method and detection system - Google Patents
Battery electric quantity detection method and detection system Download PDFInfo
- Publication number
- CN112198442A CN112198442A CN202011190563.3A CN202011190563A CN112198442A CN 112198442 A CN112198442 A CN 112198442A CN 202011190563 A CN202011190563 A CN 202011190563A CN 112198442 A CN112198442 A CN 112198442A
- Authority
- CN
- China
- Prior art keywords
- voltage
- current
- battery
- load
- moment
- 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.)
- Pending
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 claims abstract description 13
- 238000005070 sampling Methods 0.000 claims description 47
- 238000007599 discharging Methods 0.000 claims description 20
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 4
- 230000003071 parasitic effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/385—Arrangements for measuring battery or accumulator variables
- G01R31/387—Determining ampere-hour charge capacity or SoC
- G01R31/388—Determining ampere-hour charge capacity or SoC involving voltage measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/389—Measuring internal impedance, internal conductance or related variables
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Secondary Cells (AREA)
Abstract
The invention discloses a battery electric quantity detection method and a detection system, wherein the detection method comprises the following steps: respectively acquiring a first voltage and a second voltage at two ends of a load at a first moment and a second moment, and a first current and a second current flowing through the load; acquiring current voltages at two ends of a load at the current moment and current flowing through the load; calculating a voltage compensation parameter by using a preset formula and the current, the first voltage, the second voltage, the first current and the second current; calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage; and acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and a battery voltage-battery electric quantity charge-discharge curve of the battery. The method can calculate the internal resistance of the battery and indirectly calculate the voltage compensation parameter, and solves the problems of poor battery voltage-battery electric quantity interpretation precision and even false alarm caused by large system load current or large internal resistance.
Description
Technical Field
The invention relates to the technical field of battery electric quantity detection, in particular to a battery electric quantity detection method and a battery electric quantity detection system.
Background
The mainstream battery power detection method at present is to simply measure the battery voltage and interpret the battery power through a battery voltage-battery power charging and discharging curve, as shown in fig. 1, a conventional battery voltage acquisition equivalent circuit diagram.
However, this method has the following problems: neglecting the internal resistance of the battery and the parasitic resistance generated by a battery socket, a circuit and the like, the battery voltage error is large when the load current is large, and the battery electric quantity interpretation precision is greatly reduced.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a battery electric quantity detection method and a battery electric quantity detection system, so that the battery electric quantity detection is more accurate.
The invention solves the technical problems by the following technical means:
in a first aspect, the present invention provides a method for detecting an electric quantity of a battery, where the battery and a load are connected in series in a circuit, the method including:
respectively acquiring a first voltage and a second voltage at two ends of the load at a first moment and a second moment, and a first current and a second current flowing through the load;
acquiring the current voltage at two ends of the load and the current flowing through the load at the current moment;
calculating a voltage compensation parameter by using a preset formula and the current, the first voltage, the second voltage, the first current and the second current;
calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage;
and acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and a battery voltage-battery electric quantity charging and discharging curve of the battery.
Further, the preset formula is as follows:
v＝I*|ΔV/ΔI|，
ΔV＝V1-V0，
ΔI＝I1-I0；
where V is a voltage compensation parameter, I is the present current through the load, V0Is a first voltage, V1Is a second voltage, I0Is a first voltage, I1Is a second voltage.
Further, the actual voltage E of the battery at the current moment is calculated by using the following formula:
E＝v+V；
wherein V is a voltage compensation parameter, and V is a current voltage across the load.
Further, the interval between the first time and the second time is not more than 1 ms.
In a second aspect, the present invention further provides a battery power detecting system for detecting a power of a battery, where the battery is connected in series with a load in a circuit, the system including:
the battery data acquisition module is positioned in the loop and used for respectively acquiring first voltage and second voltage at two ends of the load at a first moment and a second moment as well as first current and second current flowing through the load; acquiring the current voltage at two ends of the load and the current flowing through the load at the current moment;
the voltage compensation parameter calculation module is used for calculating a voltage compensation parameter by utilizing a preset formula and the current, the first voltage, the second voltage, the first current and the second current;
the battery actual voltage calculation module is used for calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage; and
and the battery electric quantity interpretation module is used for acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and a battery voltage-battery electric quantity charging and discharging curve of the battery.
Furthermore, the battery data acquisition module comprises a current sampling unit, a voltage sampling unit and a sampling point control unit, wherein the sampling point control unit is used for controlling the current sampling unit to collect the current flowing through the load at a preset moment and controlling the voltage sampling unit to collect the voltages at two ends of the load at a preset moment.
Further, the current sampling unit comprises a current sampling resistor and a charging and discharging current detection circuit, the current sampling resistor is connected in series in the loop, the charging and discharging current detection circuit is connected at two ends of the sampling resistor respectively, and the output end of the charging and discharging current detection circuit is connected with the sampling point control unit.
Further, the charge and discharge current detection circuit includes a current detection amplifier and a reference voltage element;
the current detection amplifier is connected with two ends of the current sampling resistor, acquires a current value flowing through the current sampling resistor through a differential signal, and outputs a voltage value corresponding to the current after amplification;
the reference voltage element is connected with the current detection amplifier and used for providing reference voltage for the current detection amplifier.
Furthermore, the voltage sampling unit comprises a voltage follower and two divider resistors, the two divider resistors are connected in series and then connected in parallel at two ends of the load, the input end of the voltage follower is connected between the two divider resistors, and the output end of the voltage follower is connected with the sampling point control unit.
Furthermore, a switch tube is connected in series between the two voltage dividing resistors.
The invention has the beneficial effects that:
the battery electric quantity detection method can calculate the internal resistance of the battery and indirectly calculate the voltage compensation parameter, and solves the problems of poor battery voltage-battery electric quantity interpretation precision and even false alarm caused by large system load current or large internal resistance.
The battery electric quantity detection system has low hardware cost and simple and reliable implementation scheme.
Drawings
In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.
FIG. 1 is a diagram of an equivalent circuit for acquiring the voltage of a conventional battery;
FIG. 2 is a flow chart of a method for detecting battery power according to the present invention;
FIG. 3 is an equivalent circuit diagram of the improved battery voltage acquisition provided by the present invention;
fig. 4 is a circuit diagram of a battery data acquisition module according to the present invention.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.
It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.
Example 1
As shown in fig. 2, the present embodiment provides a method for detecting a battery level, where the battery and a load are connected in series in a circuit, the method includes:
s1, respectively obtaining a first voltage and a second voltage at two ends of the load at a first moment and a second moment, and a first current and a second current flowing through the load;
s2, acquiring the current voltage at two ends of the load and the current flowing through the load at the current moment;
s3, calculating a voltage compensation parameter by using a preset formula and the current, the first voltage, the second voltage, the first current and the second current;
s4, calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage;
and S5, acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and the battery voltage-battery electric quantity charging and discharging curve of the battery.
Specifically, the preset formula is as follows:
v＝I*|ΔV/ΔI|，
ΔV＝V1-V0，
ΔI＝I1-I0；
where V is a voltage compensation parameter, I is the present current through the load, V0Is a first voltage, V1Is a second voltage, I0Is a first voltage, I1Is a second voltage.
After the voltage compensation parameter v is calculated, the actual voltage E of the battery at the current moment can be calculated by using the following formula:
E＝v+V；
wherein V is a voltage compensation parameter, and V is a current voltage across the load.
In this embodiment, an interval between the first time and the second time is not greater than 1 ms.
Example 2
In a second aspect, the present invention further provides a battery power detection system for detecting a power of a battery by the battery power detection method provided in embodiment 1, where the battery and a load are connected in series in a loop, and the system includes:
the battery data acquisition module is positioned in the loop and used for respectively acquiring first voltage and second voltage at two ends of the load at a first moment and a second moment as well as first current and second current flowing through the load; acquiring the current voltage at two ends of the load and the current flowing through the load at the current moment;
the voltage compensation parameter calculation module is used for calculating a voltage compensation parameter by utilizing a preset formula and the current, the first voltage, the second voltage, the first current and the second current;
the battery actual voltage calculation module is used for calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage; and
and the battery electric quantity interpretation module is used for acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and a battery voltage-battery electric quantity charging and discharging curve of the battery.
Specifically, the improved battery voltage detection scheme of this embodiment is shown in fig. 3, and it is assumed that the actual voltage of the battery is E, the internal resistance and the parasitic resistance of the battery are r, the charging and discharging current of the battery is I, and the voltage across the battery load is V. The AD sampling period is set to 1ms, and the magnitude of r can be derived from the following equation:
E0＝I0*r+V0； (1)
E1＝I1*r+V1； (2)
where E1 is separated from E0 by one AD sample period. Then equation (2) minus equation (1) yields:
ΔE＝ΔI*r+ΔV； (3)
since the sampling period is 1ms, which is very short, Δ E → 0, r is considered to remain unchanged in practical application. Then it can be calculated:
r＝|ΔV/ΔI|； (4)
indirectly obtaining the internal resistance r through the voltage change delta V caused by the detected current change delta I, and then determining the compensation voltage parameter as follows according to the detected current I:
v＝I*r； (5)
the actual battery voltage E is then:
E＝v+V； (6)
combining equations (4) (5) yields:
E＝I*|ΔV/ΔI|+V； (7)
therefore, the actual battery voltage E can be accurately obtained by the formula (7).
In this embodiment, the battery data acquisition module includes a current sampling unit, a voltage sampling unit, and a sampling point control unit, where the sampling point control unit is configured to control the current sampling unit to collect current flowing through the load at a predetermined time, and control the voltage sampling unit to collect voltages at two ends of the load at a predetermined time.
Specifically, as shown in fig. 4, the current sampling unit includes a current sampling resistor R2 and a charging and discharging current detection circuit, the current sampling resistor R2 is connected in series in the loop, the charging and discharging current detection circuit is respectively connected to two ends of the current sampling resistor R2, and an output end of the charging and discharging current detection circuit is connected to the sampling point control unit.
The charging and discharging current detection circuit comprises a current detection amplifier and a reference voltage element;
the current detection amplifier U2 is connected with two ends of the current sampling resistor R2, obtains the current value flowing through the current sampling resistor R2 through differential signals, and outputs the voltage value corresponding to the current after amplification;
the reference voltage element U3 is connected to the current sense amplifier U2, and is used to provide a reference voltage for the current sense amplifier U2, which ensures that the U2 can detect the charging and discharging bidirectional current.
In this embodiment, the current detection amplifier U2 has a model number INA199A, and the reference voltage element U3 has a model number AD8515 ARTZ.
Specifically, as shown in fig. 4, the voltage sampling unit includes a voltage follower U1 and two voltage dividing resistors R1 and R7, the two voltage dividing resistors are connected in series and then connected in parallel to two ends of the load, an input end of the voltage follower U1 is connected between the two voltage dividing resistors, and an output end of the voltage follower U1 is connected to the sampling point control unit.
Further, in order to reduce the static current loss of the battery in the non-power-on state and avoid the over-low response speed of the voltage follower U1 caused by the over-large resistance of the voltage dividing network formed by R1 and R7, a switch tube Q1 is connected in series between the two voltage dividing resistors, and the switch tube Q1 is an NMOS tube.
In summary, the battery power detection method provided by the embodiment of the invention can calculate the internal resistance of the battery, indirectly calculate the voltage compensation parameter, and solve the problems of poor battery voltage-battery power interpretation precision and even false alarm caused by large system load current or large internal resistance.
The battery electric quantity detection system has low hardware cost and simple and reliable implementation scheme.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.
Claims (10)
1. A method for detecting battery power is provided, which is used to detect the power of a battery, the battery and a load are connected in series in a loop, and the method comprises the following steps:
respectively acquiring a first voltage and a second voltage at two ends of the load at a first moment and a second moment, and a first current and a second current flowing through the load;
acquiring the current voltage at two ends of the load and the current flowing through the load at the current moment;
calculating a voltage compensation parameter by using a preset formula and the current, the first voltage, the second voltage, the first current and the second current;
calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage;
and acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and a battery voltage-battery electric quantity charging and discharging curve of the battery.
2. The method of claim 1, wherein the method comprises: the preset formula is as follows:
v＝I*|ΔV/ΔI|，
ΔV＝V1-V0，
ΔI＝I1-I0；
where V is a voltage compensation parameter, I is the present current through the load, V0Is a first voltage, V1Is a second voltage, I0Is a first voltage, I1Is a second voltage.
3. The method of claim 2, wherein the step of detecting the battery power level comprises the steps of: calculating the actual voltage E of the battery at the current moment by using the following formula:
E＝v+V；
wherein V is a voltage compensation parameter, and V is a current voltage across the load.
4. The method as claimed in claim 1, wherein the interval between the first time and the second time is not greater than 1 ms.
5. A battery level detection system for detecting a level of a battery, the battery being connected in series with a load in a circuit, comprising:
the battery data acquisition module is positioned in the loop and used for respectively acquiring first voltage and second voltage at two ends of the load at a first moment and a second moment as well as first current and second current flowing through the load; acquiring the current voltage at two ends of the load and the current flowing through the load at the current moment;
the voltage compensation parameter calculation module is used for calculating a voltage compensation parameter by utilizing a preset formula and the current, the first voltage, the second voltage, the first current and the second current;
the battery actual voltage calculation module is used for calculating the actual voltage of the battery at the current moment according to the voltage compensation parameter and the current voltage; and
and the battery electric quantity interpretation module is used for acquiring the electric quantity of the battery according to the actual voltage of the battery at the current moment and a battery voltage-battery electric quantity charging and discharging curve of the battery.
6. The battery level detection system of claim 5, wherein: the battery data acquisition module comprises a current sampling unit, a voltage sampling unit and a sampling point control unit, wherein the sampling point control unit is used for controlling the current sampling unit to collect current flowing through the load at a preset moment and controlling the voltage sampling unit to collect voltages at two ends of the load at a preset moment.
7. The battery level detection system of claim 6, wherein: the current sampling unit comprises a current sampling resistor and a charging and discharging current detection circuit, the current sampling resistor is connected in series in the loop, the charging and discharging current detection circuit is connected at two ends of the sampling resistor respectively, and the output end of the charging and discharging current detection circuit is connected with the sampling point control unit.
8. The battery level detection system of claim 7, wherein: the charging and discharging current detection circuit comprises a current detection amplifier and a reference voltage element;
the current detection amplifier is connected with two ends of the current sampling resistor, acquires a current value flowing through the current sampling resistor through a differential signal, and outputs a voltage value corresponding to the current after amplification;
the reference voltage element is connected with the current detection amplifier and used for providing reference voltage for the current detection amplifier.
9. The battery level detection system of claim 6, wherein: the voltage sampling unit comprises a voltage follower and two divider resistors, the two divider resistors are connected in series and then connected in parallel at two ends of the load, the input end of the voltage follower is connected between the two divider resistors, and the output end of the voltage follower is connected with the sampling point control unit.
10. The battery level detection system of claim 9, wherein: a switch tube is connected in series between the two voltage dividing resistors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011190563.3A CN112198442A (en) | 2020-10-30 | 2020-10-30 | Battery electric quantity detection method and detection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011190563.3A CN112198442A (en) | 2020-10-30 | 2020-10-30 | Battery electric quantity detection method and detection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112198442A true CN112198442A (en) | 2021-01-08 |
Family
ID=74012163
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011190563.3A Pending CN112198442A (en) | 2020-10-30 | 2020-10-30 | Battery electric quantity detection method and detection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112198442A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112991024A (en) * | 2021-04-22 | 2021-06-18 | 北京小白世纪网络科技有限公司 | Method and system for renting shared medical intelligence detection robot |
| CN115542171A (en) * | 2022-11-02 | 2022-12-30 | 深圳市好盈科技股份有限公司 | Battery electric quantity calculation method, system, equipment and medium |
| CN118112441A (en) * | 2024-02-08 | 2024-05-31 | 中国铁塔股份有限公司 | Battery electric quantity measuring circuit |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100280777A1 (en) * | 2008-01-11 | 2010-11-04 | Sk Energy Co., Ltd. | Method for Measuring SOC of a Battery in a Battery Management System and the Apparatus Thereof |
| CN102944847A (en) * | 2012-11-20 | 2013-02-27 | 无锡中星微电子有限公司 | Battery electric quantity detection method and system |
| CN103383435A (en) * | 2013-04-26 | 2013-11-06 | 上海理工大学 | System and method for on-line dynamic measurement of electric quantity of lithium ion batteries |
| CN105785269A (en) * | 2014-12-22 | 2016-07-20 | 深圳市中兴微电子技术有限公司 | Battery electricity level metering system and method |
| CN108061856A (en) * | 2016-11-09 | 2018-05-22 | 广东大仓机器人科技有限公司 | The method for calculating battery capacity by measuring the internal resistance of cell in real time |
| CN213337948U (en) * | 2020-10-30 | 2021-06-01 | 深圳哈维生物医疗科技有限公司 | Battery electric quantity detection system |
-
2020
- 2020-10-30 CN CN202011190563.3A patent/CN112198442A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100280777A1 (en) * | 2008-01-11 | 2010-11-04 | Sk Energy Co., Ltd. | Method for Measuring SOC of a Battery in a Battery Management System and the Apparatus Thereof |
| CN102944847A (en) * | 2012-11-20 | 2013-02-27 | 无锡中星微电子有限公司 | Battery electric quantity detection method and system |
| CN103383435A (en) * | 2013-04-26 | 2013-11-06 | 上海理工大学 | System and method for on-line dynamic measurement of electric quantity of lithium ion batteries |
| CN105785269A (en) * | 2014-12-22 | 2016-07-20 | 深圳市中兴微电子技术有限公司 | Battery electricity level metering system and method |
| CN108061856A (en) * | 2016-11-09 | 2018-05-22 | 广东大仓机器人科技有限公司 | The method for calculating battery capacity by measuring the internal resistance of cell in real time |
| CN213337948U (en) * | 2020-10-30 | 2021-06-01 | 深圳哈维生物医疗科技有限公司 | Battery electric quantity detection system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112991024A (en) * | 2021-04-22 | 2021-06-18 | 北京小白世纪网络科技有限公司 | Method and system for renting shared medical intelligence detection robot |
| CN115542171A (en) * | 2022-11-02 | 2022-12-30 | 深圳市好盈科技股份有限公司 | Battery electric quantity calculation method, system, equipment and medium |
| CN118112441A (en) * | 2024-02-08 | 2024-05-31 | 中国铁塔股份有限公司 | Battery electric quantity measuring circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3480605A1 (en) | Current detection system, method and device | |
| CN112198442A (en) | Battery electric quantity detection method and detection system | |
| CN102064597B (en) | Energy storage device | |
| CN203216630U (en) | Automatic temperature detection system | |
| CN109085510B (en) | Circuit and method for on-line detection and automatic calibration of currents of multiple charge and discharge channels | |
| CN110726921B (en) | IGBT module service life monitoring method | |
| CN107181300A (en) | Charge protector, the method and apparatus for calibrating charging equipment | |
| CN105277791A (en) | Method for on-line detection of internal resistance of a storage battery by performing low-direct-current discharge twice | |
| CN102928109A (en) | Signal collecting circuit | |
| CN103424601A (en) | Voltage detecting circuit | |
| CN103488229A (en) | Automatic fine-tuning circuit for band-gap reference | |
| CN105785269A (en) | Battery electricity level metering system and method | |
| CN114062900A (en) | Operational amplifier circuit offset voltage testing method | |
| CN102520360B (en) | Battery voltage detection system in battery pack and method for detecting voltage and correcting error by employing system | |
| CN213337948U (en) | Battery electric quantity detection system | |
| CN108304023B (en) | High-load stability compensation circuit of switching power supply | |
| CN102809443A (en) | Method and circuit for measuring temperature | |
| CN103052889A (en) | Systems and methods for high-sensitivity detection of input bias current | |
| CN105277292A (en) | Temperature measurement device | |
| CN103018655B (en) | Overcharge voltage detection circuit of battery protection circuit | |
| CN102478422A (en) | Zero drift simulation calibrating method and device thereof | |
| CN106841751B (en) | Voltage rise and fall quantitative detection circuit/device | |
| CN111913044A (en) | Method and circuit for detecting impedance of powered device in PoE system | |
| CN2720457Y (en) | Semiconductor laser characteristic parameter testing device | |
| CN212540498U (en) | Self-balancing bridge circuit for millimeter wave power meter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |