CN212321657U - Performance detection device of wheel speed sensor - Google Patents
Performance detection device of wheel speed sensor Download PDFInfo
- Publication number
- CN212321657U CN212321657U CN202020318950.XU CN202020318950U CN212321657U CN 212321657 U CN212321657 U CN 212321657U CN 202020318950 U CN202020318950 U CN 202020318950U CN 212321657 U CN212321657 U CN 212321657U
- Authority
- CN
- China
- Prior art keywords
- capacitor
- resistor
- wheel speed
- pin
- speed sensor
- 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.)
- Active
Links
Images
Abstract
The utility model discloses a performance detection device of fast sensor of wheel relates to the sensor and detects. The method comprises the following steps: a controller integrated with: the input end of the power supply voltage stabilizing circuit is connected with the anode of the vehicle battery; the input end of the singlechip is connected with the output end of the power voltage stabilizing circuit, the singlechip is integrated with a microprocessor which is respectively connected with a timer, a pulse width modulation circuit and an input/output port, and the pulse width modulation circuit is connected with the input/output port; amplifier circuit, input port, monitoring device, the integrated input/output port that has: the input end of the acquisition circuit is connected with the output end of the singlechip; the processing circuit is respectively connected with the output end of the acquisition circuit and a display part; and one end of the wheel speed sensor is connected with the output end of the amplifying circuit, and the other end of the wheel speed sensor is connected with the input end of the acquisition circuit. Has the following beneficial effects: and pulse width modulation waveforms with different frequencies and different duty ratios are output, and a wheel speed sensor is automatically detected, so that reliable performance is ensured.
Description
Technical Field
The utility model relates to a sensor detection area especially relates to a performance detection device of fast sensor of wheel.
Background
The wheel speed sensor is used for measuring the rotating speed of the wheels of the automobile. The wheel speed information is the essential collected data of modern automobiles, wherein in the running process of the automobiles, the running of an automatic gearbox, an Electronic Stability Program (ESP) of the automobiles, a dynamic control system (VDC) of the automobiles and an anti-lock braking system (ABS) of the automobiles needs to acquire the wheel speed information. Before the wheel speed sensor product leaves a factory, the wheel speed sensor needs to be strictly detected.
At present, in the test technology in the field, a simple PWM waveform can be generated, but a combined waveform formed by combining different frequencies and different duty ratios cannot be output, and detection is performed on the basis of the combined waveform. Therefore need the production of combination waveform and automated inspection both combine together just can realize the detection to the fast sensor of wheel, the utility model discloses a solve above-mentioned problem, provided a fast sensor's of wheel performance detection device, produce the PWM waveform of different frequency and different duty cycles to carry out automated inspection to this PWM waveform, with the performance of judging the fast sensor of wheel.
Disclosure of Invention
The utility model discloses a solve above-mentioned problem, provided a performance detection device of fast sensor of wheel now, include:
a controller having integrated thereon:
the input end of the power supply voltage stabilizing circuit is connected with the power supply anode of the vehicle battery;
the input end of the single chip microcomputer is connected with the output end of the power voltage stabilizing circuit, a microprocessor is integrated on the single chip microcomputer, the microprocessor is respectively connected with a timer, a pulse width modulation circuit and an input/output port, and the pulse width modulation circuit is connected with the input/output port;
the input end of the amplifying circuit is connected with the input/output port, and the monitoring device is integrated with:
the input end of the acquisition circuit is connected with the output end of the singlechip;
the processing circuit is respectively connected with the output end of the acquisition circuit and a display part;
and one end of the wheel speed sensor is connected with the output end of the amplifying circuit, and the other end of the wheel speed sensor is connected with the input end of the acquisition circuit.
Preferably, the power supply voltage stabilizing circuit specifically includes:
one end of the first capacitor is connected with the power supply anode of the vehicle battery, and the other end of the first capacitor is grounded;
the anode of the first diode is respectively connected with the first capacitor and the power supply anode;
the anode of the first polarity capacitor is connected with the cathode of the first diode, and the cathode of the first polarity capacitor is grounded;
a first end of the first resistor is connected with the anode of the first polarity capacitor, a second end of the first resistor is respectively connected with a first end of a second resistor and a first end of a second capacitor, and a second end of the second resistor is connected with the second end of the second capacitor and is grounded;
one end of the third capacitor is connected with the first end of the second resistor, and the other end of the third capacitor is grounded;
a first pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a tenth pin, an eleventh pin and a twelfth pin of the voltage stabilizing chip are respectively grounded, a second pin of the voltage stabilizing chip is grounded through a fourth capacitor, a seventh pin of the voltage stabilizing chip is connected with a reset pin of the single chip microcomputer, an eighth pin of the voltage stabilizing chip is vacant, and a ninth pin and a fourteenth pin of the voltage stabilizing chip are connected with a power supply pin of the single chip microcomputer;
a second polarity capacitor, wherein the anode of the second polarity capacitor is connected to the ninth pin and the fourteenth pin respectively, and the cathode of the second polarity capacitor is grounded;
and the fourth capacitor is connected in parallel with the second polarity capacitor.
Preferably, the amplifying circuit specifically includes:
a first end of the third resistor is connected with the input/output port, and a second end of the third resistor is connected with a fourth resistor in series and is grounded through the fourth resistor;
the grid electrode of the metal-oxide-semiconductor field effect transistor is respectively connected with the input/output port and the first end of the third resistor, the source electrode of the metal-oxide-semiconductor field effect transistor is connected with the wheel speed sensor, and the drain electrode of the metal-oxide-semiconductor field effect transistor is connected with the first end of a fifth resistor;
a third polar capacitor, wherein the positive electrode of the third polar capacitor is connected with the second end of the fifth resistor, and the negative electrode of the third polar capacitor is grounded;
a cathode of the second diode is respectively connected with an anode of the third polar capacitor and a second end of the fifth resistor, and an anode of the second diode is connected with a power supply;
and one end of the fifth capacitor is respectively connected with the anode of the second diode and the power supply, and the other end of the fifth capacitor is grounded.
Preferably, the metal oxide semiconductor field effect transistor is an N-type metal oxide semiconductor field effect transistor.
Preferably, the wheel speed sensor is a two-wire wheel speed sensor.
Preferably, the positive electrode of the wheel speed sensor is connected to the output end of the amplifying circuit, the negative electrode of the wheel speed sensor is connected to the first end of a sixth resistor and the input end of the collecting circuit, respectively, and the second end of the sixth resistor is grounded.
Preferably, the resistance value of the sixth resistor is 75 ohms.
Preferably, a switch is arranged between the input end of the power supply voltage stabilizing circuit and the positive electrode of the power supply of the vehicle battery.
Has the following beneficial effects:
the utility model discloses the performance detection device of wheel speed sensor realizes exporting the pulse width modulation waveform of different frequencies and different duty cycles to the fast sensor of automated inspection wheel detects under the unstable condition of automobile-used battery voltage with the fast sensor of simulation wheel, ensures that the fast sensor of wheel has reliable performance.
Drawings
Fig. 1 is a system diagram of a performance detecting device of a wheel speed sensor according to a preferred embodiment of the present invention;
FIG. 2 is a circuit diagram of a power supply voltage stabilizing circuit according to a preferred embodiment of the present invention;
fig. 3 is a circuit diagram of an amplifying circuit according to a preferred embodiment of the present invention;
FIG. 4 is a waveform diagram of the controller output according to the preferred embodiment of the present invention;
fig. 5 is a connection structure diagram of a wheel speed sensor according to a preferred embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.
The present invention will be further described with reference to the accompanying drawings and specific embodiments, but the present invention is not limited thereto.
The utility model discloses a solve above-mentioned problem, now proposed a performance detection device of fast sensor of wheel, as shown in FIG. 1, include:
a controller 1, wherein the controller 1 is integrated with:
the input end of the power supply voltage stabilizing circuit 12 is connected with the power supply anode of the vehicle battery;
the input end of the single chip microcomputer 13 is connected with the output end of the power voltage stabilizing circuit 12, a microprocessor 14 is integrated on the single chip microcomputer 13, the microprocessor 14 is respectively connected with a timer 15, a pulse width modulation circuit 16 and an input/output port 17, and the pulse width modulation circuit 16 is connected with the input/output port 17;
an amplifying circuit 18, an input end of the amplifying circuit 18 is connected to the input/output port 17, and the monitoring device 2 is integrated with:
the input end of the acquisition circuit 21 is connected with the output end of the singlechip 13;
the processing circuit 22 is respectively connected with the output end of the acquisition circuit 21 and a display part 23;
and one end of the wheel speed sensor 3 is connected with the output end of the amplifying circuit 18, and the other end of the wheel speed sensor 3 is connected with the input end of the acquisition circuit 21.
Specifically, in this embodiment, the utility model discloses a produced undulant when simulating automobile-used battery power supply to realize the fast sensor of automated inspection wheel under this undulant. The utility model discloses performance detection device of wheel speed sensor sets up the controller and includes: the controller 1, the role of the controller 1 is mainly to generate the waveform of the voltage fluctuation of the vehicle battery and output a trigger signal to trigger the monitoring device 2 to start monitoring the wheel speed sensor 3. The controller 1 mainly comprises a power supply voltage stabilizing circuit 12, a single chip microcomputer 13 and an amplifying circuit 18, wherein the preferred single chip microcomputer is an MC9S12G48 single chip microcomputer, and the power supply voltage stabilizing circuit 12 is used for converting the voltage of a vehicle battery with 12V into the voltage of 5V for the normal work of the single chip microcomputer 13. Preferably, the power supply voltage stabilizing circuit 12 is a circuit based on a TLE42694 voltage stabilizing chip. Vbat in the power voltage stabilizing circuit 12 is accessed from the anode of the vehicle battery, and VCC in the power voltage stabilizing circuit 12 outputs 5V voltage to the power supply pin of the singlechip 13 for supplyThe singlechip 13 normally works; the seventh pin is connected to the reset pin of the single chip 13. The single chip microcomputer 13 is provided with a microprocessor 14, a timer 15, a pulse width modulation circuit 16 and an input/output port 17, the microprocessor 14 is preferably an MC9S12G48 chip, an original waveform is generated in the MC9S12G48 chip, and the timer 15 generates a waveform which changes according to a set time by timing the original waveform. As shown in fig. 4, TPRET corresponding to time periodPREThe waveform is an initial waveform T under pre-electrificationPWMT corresponding to time periodPWMThe waveform is a pulse width modulation waveform modulated by the pulse width modulation circuit 16, preferably, TPWMThe frequency of the waveform can be 5KHz, 10KHz, 20KHz, 50KHz and 100KHz, the duty ratio can be 20 percent, 50 percent and 80 percent, and the two can be mutually combined and generated through a software algorithm in the singlechip; t isIDLET corresponding to time periodIDLEThe waveform is generated when the singlechip sends a trigger signal, preferably TIDLEIs set to 100ms, TOFFIndicating a detection delay time, preferably, TOFFThe time is set to 5ms or more. The pulse width modulation circuit 16 is used to generate a pulse width modulated waveform, i.e., TPWMAnd (4) waveform, namely waveform with certain frequency and duty ratio. The input/output port 17 is mainly used for outputting TPWMThe waveform and the trigger signal, the form of the trigger signal is that high level "1" indicates valid, low level "0" indicates invalid, the trigger signal will be output to the monitoring device 2 through the input/output port 17, the monitoring device 2 will start to carry out voltage detection on the wheel speed sensor 3 when receiving the valid signal "1", otherwise, the trigger signal will not be ignored when receiving "0". The input/output port 17 mainly has two functions: first, TPWMAfter the waveform is generated, T with the amplitude of 5V is output through the input/output port 17PWMWaveform, which is required to be output to the amplifying circuit 18 for amplification and then output T shown in FIG. 4PWMA waveform; second, the one-chip microcomputer 13 realizes T in fig. 4IDLEWhen the initial time arrives, a trigger signal is sent through the input/output port 17 to trigger the monitoring device 2 to start monitoring the wheel speed sensor 3 (i.e. the region monitored by the monitoring device 2 is T)IDLEThe area of (d). The amplification circuit 18 functions to amplify the amplitudeThe 5V waveform is amplified to the 12V amplitude waveform, and the change of the amplitude of the waveform in the longitudinal direction is realized. The amplifier circuit 18 is required for two main reasons: firstly, the amplitude of the waveform output by the input/output port 17 in the single chip microcomputer 13 is 5V, which cannot reach the normal working voltage range of the wheel speed sensor 3; secondly, the waveform frequency needs to be reduced through the amplifying circuit, the response time of the amplifying circuit 18 needs to be fast, the highest frequency of the waveform generated by the single chip microcomputer 13 can reach 100KHz, and if the response of the amplifying circuit 18 is not fast enough, the amplified signal of the waveform can deform and cannot meet the waveform requirement. Thirdly, the output power is increased, the loading capacity of the waveform output by the single chip microcomputer 13 is poor, and the loading capacity of the waveform needs to be improved.
In a preferred embodiment of the present invention, as shown in fig. 2, the power voltage stabilizing circuit 12 specifically includes:
a first capacitor C1, wherein one end of the first capacitor C1 is connected with the power supply positive electrode of the vehicle battery, and the other end is grounded;
a first diode D1, the anode of the first diode D1 is connected with the first capacitor C1 and the power supply anode respectively;
a first polarity capacitor E1, wherein the anode of the first polarity capacitor E1 is connected to the cathode of the first diode D1, and the cathode of the first polarity capacitor E1 is grounded;
a first resistor R1, a first end of the first resistor R1 is connected to the positive electrode of the first polarity capacitor E1, a second end of the first resistor R1 is connected to a first end of a second resistor R2 and a first end of a second capacitor, respectively, and a second end of the second resistor R2 is connected to the second end of the second capacitor C2 and is also grounded;
a third capacitor C3, one end of the third capacitor C3 is connected to the first end of the second resistor R2, and the other end is grounded;
a first pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a tenth pin, an eleventh pin and a twelfth pin of the voltage stabilization chip U1 are respectively grounded, a second pin of the voltage stabilization chip is grounded through a fourth capacitor C4, a seventh pin of the voltage stabilization chip U1 is connected with a reset pin of the single chip microcomputer 13, an eighth pin of the voltage stabilization chip U1 is vacant, and a ninth pin and a fourteenth pin of the voltage stabilization chip U1 are connected with a power supply pin of the single chip microcomputer 13;
a second polarity capacitor E2, wherein the positive electrode of the second polarity capacitor E2 is connected to the ninth pin and the fourteenth pin, respectively, and the negative electrode of the second polarity capacitor E2 is grounded;
a fourth capacitor C4, the fourth capacitor C4 being connected in parallel with the second polarity capacitor E2.
In a preferred embodiment of the present invention, as shown in fig. 3, the amplifying circuit 18 specifically includes:
a third resistor R3, a first end of the third resistor R3 is connected to the input/output port, a second end of the third resistor R3 is connected in series with a fourth resistor R4 and is grounded through the fourth resistor R4;
a mosfet Q1, wherein a gate of the mosfet Q1 is connected to the input/output port and a first end of the third resistor R3, respectively, a source of the mosfet Q1 is connected to the wheel speed sensor 3, and a drain of the mosfet Q1 is connected to a first end of a fifth resistor R5;
a third polar capacitor E3, wherein the anode of the third polar capacitor E3 is connected to the second end of the fifth resistor R5, and the cathode of the third polar capacitor E3 is grounded;
a second diode D2, wherein a cathode of the second diode D2 is connected to an anode of the third polar capacitor E3 and a second end of the fifth resistor R5, respectively, and an anode of the second diode D2 is connected to a power supply;
one end of the fifth capacitor C5 is connected to the anode of the second diode D2 and the power supply, respectively, and the other end of the fifth capacitor C5 is grounded.
Specifically, in this embodiment, the waveform is output by the amplifying circuit 18, so as to satisfy the voltage value required by the wheel speed sensor 3, and meanwhile, the characteristics of strong loading capacity, fast response time, no waveform deformation and the like are provided. The power supply voltage of the amplifying circuit 18 is 12V, the mosfet Q1 is preferably an N-type mosfet, Input represents a waveform with an amplitude of 5V Output from the single chip 13, and Output represents a waveform amplified to 12V by the amplifying circuit 18 and then Output to the wheel speed sensor 3.
In the preferred embodiment of the present invention, the mosfet Q1 is an N-type mosfet.
In the preferred embodiment of the present invention, the wheel speed sensor 3 is a two-wire wheel speed sensor.
In a preferred embodiment of the present invention, as shown in fig. 5, the positive electrode of the wheel speed sensor 3 is connected to the output terminal of the amplifying circuit 18, the negative electrode of the wheel speed sensor 3 is connected to the first terminal of a sixth resistor R6 and the input terminal of the collecting circuit 21, respectively, and the second terminal of the sixth resistor R6 is grounded.
Specifically, in this embodiment, the wheel speed sensor 3 is a two-wire system, and the two-wire system wheel speed sensor 3 has a simple structure and is connected in such a manner that one end is connected to the positive electrode and the other end is connected to the negative electrode of the power supply, so that the normal start and detection of the wheel speed sensor 3 can be realized, which is very convenient.
The two-wire wheel speed sensor 3 outputs a current signal when working normally, the magnitude of the passing current needs to be controlled within the range of 5.9mA-16.8mA, but the wheel speed sensor 3 is generally tested by voltage to detect the performance of the wheel speed sensor 3, so that the current needs to be converted into voltage to realize the detection of the voltage to reflect the performance of the wheel speed sensor 3, preferably, a sixth resistor is connected in series to test the voltage of the sixth resistor, the negative electrode of the wheel speed sensor 3 is respectively connected with the first end of a sixth resistor R6 and the input end of the acquisition circuit 21, the second end of the sixth resistor R6 is grounded, and whether the detection of the wheel speed sensor 3 is qualified is judged by detecting whether the voltage value at the two ends of the sixth resistor R6 is within a set range. Preferably, the resistance value of the sixth resistor R6 is 75 ohms, and the performance detection of the wheel speed sensor 3 is realized by detecting whether the voltage value at the two ends of the sixth resistor R6 is in the range of 0.4V-1.26V.
In a preferred embodiment of the present invention, the resistance of the sixth resistor R6 is 75 ohms.
In the preferred embodiment of the present invention, a switch is disposed between the input terminal of the power voltage stabilizing circuit 12 and the positive power supply terminal of the vehicle battery.
The above description is only an example of the preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and those skilled in the art should be able to realize the equivalent alternatives and obvious variations of the present invention.
Claims (8)
1. A performance detection device of a wheel speed sensor, comprising:
a controller having integrated thereon:
the input end of the power supply voltage stabilizing circuit is connected with the power supply anode of the vehicle battery;
the input end of the single chip microcomputer is connected with the output end of the power voltage stabilizing circuit, a microprocessor is integrated on the single chip microcomputer, the microprocessor is respectively connected with a timer, a pulse width modulation circuit and an input/output port, and the pulse width modulation circuit is connected with the input/output port;
an amplifying circuit, the input end of the amplifying circuit is connected with the input/output port,
a monitoring device, the monitoring device having integrated thereon:
the input end of the acquisition circuit is connected with the output end of the singlechip;
the processing circuit is respectively connected with the output end of the acquisition circuit and a display part;
and one end of the wheel speed sensor is connected with the output end of the amplifying circuit, and the other end of the wheel speed sensor is connected with the input end of the acquisition circuit.
2. The device for detecting the performance of a wheel speed sensor according to claim 1, wherein the power supply voltage stabilizing circuit specifically comprises:
one end of the first capacitor is connected with the power supply anode of the vehicle battery, and the other end of the first capacitor is grounded;
the anode of the first diode is respectively connected with the first capacitor and the power supply anode;
the anode of the first polarity capacitor is connected with the cathode of the first diode, and the cathode of the first polarity capacitor is grounded;
a first end of the first resistor is connected with the anode of the first polarity capacitor, a second end of the first resistor is respectively connected with a first end of a second resistor and a first end of a second capacitor, and a second end of the second resistor is connected with the second end of the second capacitor and is grounded;
one end of the third capacitor is connected with the first end of the second resistor, and the other end of the third capacitor is grounded;
a first pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a tenth pin, an eleventh pin and a twelfth pin of the voltage stabilizing chip are respectively grounded, a second pin of the voltage stabilizing chip is grounded through a fourth capacitor, a seventh pin of the voltage stabilizing chip is connected with a reset pin of the single chip microcomputer, an eighth pin of the voltage stabilizing chip is vacant, and a ninth pin and a fourteenth pin of the voltage stabilizing chip are connected with a power supply pin of the single chip microcomputer;
a second polarity capacitor, wherein the anode of the second polarity capacitor is connected to the ninth pin and the fourteenth pin respectively, and the cathode of the second polarity capacitor is grounded;
and the fourth capacitor is connected in parallel with the second polarity capacitor.
3. The performance detection device of a wheel speed sensor according to claim 1, wherein the amplification circuit specifically includes:
a first end of the third resistor is connected with the input/output port, and a second end of the third resistor is connected with a fourth resistor in series and is grounded through the fourth resistor;
the grid electrode of the metal-oxide-semiconductor field effect transistor is respectively connected with the input/output port and the first end of the third resistor, the source electrode of the metal-oxide-semiconductor field effect transistor is connected with the wheel speed sensor, and the drain electrode of the metal-oxide-semiconductor field effect transistor is connected with the first end of a fifth resistor;
a third polar capacitor, wherein the positive electrode of the third polar capacitor is connected with the second end of the fifth resistor, and the negative electrode of the third polar capacitor is grounded;
a cathode of the second diode is respectively connected with an anode of the third polar capacitor and a second end of the fifth resistor, and an anode of the second diode is connected with a power supply;
and one end of the fifth capacitor is respectively connected with the anode of the second diode and the power supply, and the other end of the fifth capacitor is grounded.
4. The apparatus of claim 3, wherein the MOSFET is an N-type MOSFET.
5. The performance detection apparatus of a wheel speed sensor according to claim 1, wherein the wheel speed sensor is a two-wire wheel speed sensor.
6. The apparatus of claim 5, wherein the positive terminal of the wheel speed sensor is connected to the output terminal of the amplifying circuit, the negative terminal of the wheel speed sensor is connected to the first terminal of a sixth resistor and the input terminal of the collecting circuit, and the second terminal of the sixth resistor is grounded.
7. The performance detection apparatus of a wheel speed sensor according to claim 6, wherein the sixth resistor has a resistance of 75 ohms.
8. The apparatus for detecting the performance of a wheel speed sensor as claimed in claim 1, wherein a switch is provided between the input terminal of the power voltage stabilizing circuit and the positive power supply terminal of the vehicle battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020318950.XU CN212321657U (en) | 2020-03-13 | 2020-03-13 | Performance detection device of wheel speed sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020318950.XU CN212321657U (en) | 2020-03-13 | 2020-03-13 | Performance detection device of wheel speed sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212321657U true CN212321657U (en) | 2021-01-08 |
Family
ID=74018462
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020318950.XU Active CN212321657U (en) | 2020-03-13 | 2020-03-13 | Performance detection device of wheel speed sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212321657U (en) |
-
2020
- 2020-03-13 CN CN202020318950.XU patent/CN212321657U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102362185B (en) | Insulation resistance measuring circuit free from influence of battery voltage | |
| JP4103280B2 (en) | Mechanical quantity sensor device | |
| CN206024113U (en) | Diagnostic circuit, audio system and integrated circuit | |
| CN204188702U (en) | A kind of current detection circuit | |
| CN106501722A (en) | A kind of battery voltage detection circuit and detecting voltage method | |
| CN107248844B (en) | A kind of photo-voltaic power supply | |
| CN203720278U (en) | Vehicle microphone status detecting circuit | |
| CN101498747A (en) | Wave crest and wave trough detection method and circuit | |
| CN112858895A (en) | Novel direct current charging pile direct current relay adhesion judgment method and circuit thereof | |
| CN212321657U (en) | Performance detection device of wheel speed sensor | |
| CN204989290U (en) | Wide dynamic range's high -pressure side current detection circuit | |
| CA2614427A1 (en) | Method and apparatus for recognizing a change-of-state in communication signals of electronic circuits | |
| CN104459289A (en) | Detection circuit and detection method based on waveform transformation | |
| CN202713135U (en) | Automobile navigator power supply filter circuit | |
| CN211731355U (en) | Vacuum pressure detection and controller for new energy automobile | |
| CN203324355U (en) | Microwave-system diverse self-checking circuit | |
| CN104597316A (en) | Weak current detecting device and method | |
| CN213934120U (en) | Relay detection circuit and detection device based on differential sampling | |
| CN211606871U (en) | Starting protection module driven by LED vehicle lamp | |
| CN204462242U (en) | Weak current signal detection device | |
| CN210166432U (en) | Low-voltage low-frequency small-signal current detection circuit | |
| US20050163326A1 (en) | Diagnostic circuit for a tweeter ina loudspeaker combination | |
| CN100478694C (en) | Module of pulsed signal input detection circuit with electric booster steering | |
| CN211426729U (en) | Fire detection alarm electric quantity detection circuit and fire detection alarm | |
| CN208417691U (en) | Solenoid valve quick response device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |