632 results about "Load resistance" patented technology

The present disclosure provides a receiver front-end circuit including: first and second input units that alternately operate according to a common mode voltage of a differential input signal and output a differential output signal; a variable resistance unit that adjusts a differential load resistance supplied to the differential output signal according to the variable resistance control signal; and a control unit generating a variable resistance control signal according to a common mode voltage of the differential input signal. According to the receiver front-end circuit disclosed by the invention, the receiving of the differential input signal with a wider common-mode voltage range can be realized under low power supply voltage, and the output amplitude of the generated differential output signal does not change greatly along with the change of the common-mode voltage of the differential input signal; therefore, the compatibility of the receiver is improved, and the power consumption is reduced.

The invention discloses an on-line monitoring and early warning method for a bus capacitor of an electric driving system, and belongs to the field of electric driving systems. The electric driving system sequentially comprises an isolating circuit, a full-wave bridge rectifier, a bus capacitor bank, an inverter, an actuator and a capacitance online testing device; the capacitor online testing device comprises a relay, a load resistor, a voltage acquisition module, a current acquisition module and a master control calculation unit. When the electric drive system is idle, a load resistor is connected to construct a test path, and current and voltage signals are collected; disconnecting a test path, constructing a degradation characterization quantity of multi-index information fusion through time-frequency domain feature extraction, and constructing an equal-length time interval sequence degradation curve; and the TCN-BRU-GRU combined prediction model carries out trend feature learning and training on the degradation curve. According to the method, waveform fitting and local and global data feature capturing of non-equal-interval time sampling are achieved, trend prediction of bus capacitor performance degradation is achieved, early warning is conducted before failure of the bus capacitor, and safe and reliable operation of an electric drive system is guaranteed.

The present application relates to a method and apparatus for controlling a wireless electrical energy transmission system, and a computer device. The method comprises: determining a real-time load resistance of a wireless electrical energy transmission system, and obtaining a trained value table, the trained value table comprising a sample load resistor, a sample primary resonant capacitor, and a sample value of correspondence between each sample load resistor and each sample primary resonant capacitor; in the trained value table, determining a real-time primary resonant capacitor of the wireless electrical energy transmission system on the basis of the real-time load resistance and the sample value; and controlling the wireless electrical energy transmission system on the basis of the real-time primary resonant capacitor. By adopting the present method, the convenience of control can be improved.

The invention provides a neutral-point potential balance control system and method for a three-level Buck direct-current converter, and belongs to the technical field of switching power supplies. The power part comprises an input voltage source, an upper voltage-dividing capacitor, a lower voltage-dividing capacitor, a first switching tube, a second switching tube, a first diode, a second diode, an output filter inductor, an output filter capacitor and an output load resistor, the upper voltage-dividing capacitor and the lower voltage-dividing capacitor are connected in series and then connected with the input voltage source in parallel, and the first diode is connected with the second diode; the cathode of the first diode is connected with the first switch tube and then connected to the anode of the voltage source, the anode of the second diode is connected with the second switch tube and then connected to the cathode of the voltage source, the midpoint of the two capacitors is connected with the midpoint of the two diodes, voltages at two ends of the lower voltage-dividing capacitor are midpoint potentials, and midpoint potential balance control is carried out by adjusting edges of switch tube driving signals. The efficiency, the power density and the reliability of the converter are improved.

The utility model discloses a miniaturized image rejection frequency mixing circuit, which comprises two passive double-balanced frequency mixers, a local oscillator bridge, a phase shift circuit and a power divider, the first input ends of the first passive double-balanced mixer and the second passive double-balanced mixer are connected with an external antenna; the second input end of the first passive double-balanced mixer is connected with the first output end of the local oscillator bridge, the second input end of the second passive double-balanced mixer is connected with the second output end of the local oscillator bridge, and the output end of the first passive double-balanced mixer is connected with the input end of the phase shift circuit. The output end of the second passive double-balanced mixer is connected with the second input end of the power divider; the isolation end of the local oscillator bridge is connected with the load resistor, and the input end of the local oscillator bridge is connected with the frequency source; the output end of the phase shift circuit is connected with the first input end of the power divider, and the output end of the power divider is connected with an external circuit. According to the utility model, the size of the image rejection mixer can be obviously reduced, and miniaturization design of a radar receiver is facilitated.

The invention provides an anti-rolling gyroscope control system and an adjusting method, and belongs to the technical field of floating type platform anti-rolling. Comprising an anti-rolling gyroscope device and a control assembly, the anti-rolling gyroscope device comprises an anti-rolling gyroscope body and a mounting base, a supporting shaft and a precession shaft are coaxially arranged on the two sides of the anti-rolling gyroscope body, and the anti-rolling gyroscope body is rotationally connected with the mounting base through the supporting shaft and the precession shaft. The control assembly comprises a stabilization permanent magnet motor and a damping adjustment control module, the stabilization permanent magnet motor is in transmission connection with the precession shaft, the damping adjustment control module comprises a controller and a load resistor group, the load resistor group is electrically connected with the stabilization permanent magnet motor, and the controller is electrically connected with the load resistor group. By adopting the anti-rolling gyroscope control system and the adjusting method, the wide-range adjustment of the damping coefficient of the anti-rolling gyroscope can be realized, and the adaptability to complex and changeable offshore anti-rolling scene requirements is improved.

The invention discloses a non-isolated quasi-series-parallel combined converter based on a switched capacitor network. The converter comprises the switched capacitor network, a non-isolated DC-DC converter, an output filter capacitor Co and a load resistor R. The combined converter gives full play to the advantages of high power density and high efficiency of a non-voltage-regulation mode of the resonant switched capacitor converter, the resonant switched capacitor network and the DC-DC chopper converter are subjected to topological combination through a partial power processing technology, and the combination has the advantages of high power density and high efficiency of the non-voltage-regulation mode of the resonant switched capacitor network and also has the advantages of high power density and high efficiency of the non-voltage-regulation mode of the DC-DC chopper converter. And the advantage of wide voltage regulation range of the DC-DC chopper converter is also fused. By means of the time-sharing charging and discharging characteristics of the capacitors, the resonant switched capacitor network and the DC-DC chopper converter are connected in series on the input side to reduce voltage stress and are connected in parallel on the output side to replace a traditional two-stage cascade mode, and higher total electric energy conversion efficiency is achieved.

The embodiment of the invention discloses a current probe circuit and a current probe, and belongs to the technical field of current measurement. In the embodiment of the invention, the current probe circuit comprises a current transformer, a load resistor and a matching resistor, two ends of a primary side coil of the current transformer are detachably connected in series with the to-be-tested element; the dotted terminal of the secondary coil of the current transformer is connected with one end of the load resistor and one end of the matching resistor, and the other end of the matching resistor is connected with the positive electrode of the oscilloscope; the synonym end of the secondary side coil of the current transformer is connected with the other end of the load resistor and the negative electrode of the oscilloscope. The oscilloscope can measure the current flowing through the element to be measured by measuring the voltage between the positive electrode and the negative electrode. The current probe circuit is low in cost and can be used in an over-range mode.

The invention discloses a three-phase wireless electric energy and signal reverse cooperative transmission system and a parameter design method thereof. The system comprises a direct-current power supply, a three-phase high-frequency inverter circuit, a three-phase primary side compensation capacitor, a three-phase secondary side compensation capacitor, a three-phase primary and secondary side magnetic coupling coil, a signal transmission channel network, a signal modulation-demodulation circuit network, an encoder, a decoder, a three-phase rectification filter circuit, a filter capacitor and a load resistor. The signal transmission channel networks respectively comprise three signal injection networks and three signal separation transmission channel networks; each signal injection network comprises a secondary side signal injection transformer, a secondary side injection signal resonant capacitor and a discharge resistor; and each signal separation transmission channel network comprises a primary side signal pickup transformer, an extraction signal resonant capacitor, a wave blocking network inductor, a wave blocking network capacitor and a sampling resistor. According to the invention, three-phase wireless energy and information parallel reverse transmission is realized, and the signal transmission rate is effectively improved while stable and efficient electric energy transmission is ensured.

A power reception device 3 includes: an estimation circuit 28 estimating a load resistance of an entire contactless power feed apparatus 1; and a reception-side communicator 27 transmitting an estimated value of the load resistance of the entire contactless power feed apparatus 1 to a power transmission device 2. The power transmission device 2 has a power supply circuit 11 supplying AC power to a transmission coil 12 supplying power to the power reception device 3. The power transmission device 2 further includes a control circuit 18 decreasing an input / output gain of a transmission-side DC-DC converter 31 included in the power supply circuit 11 by a predetermined amount when the estimated value of the load resistance is less than a predetermined allowed lower limit, and maintaining or increasing the input / output gain when the estimated value of the load resistance is equal to or greater than the predetermined allowed lower limit.

The invention provides an electric bicycle AC charging pile load short circuit detection method and system, and is applied to the technical field of charging pile load detection, and the method comprises the steps: switching on a target switch in response to the detection of the insertion of a charger plug; obtaining the first detection voltage, the first detection current and the first detection active power after preprocessing through a metering chip, and switching off a target switch; determining a first detection power factor of the charging pile based on the first detection voltage, the first detection current and the first detection active power; determining a first detection load resistance of the charging pile based on the first detection voltage and the first detection current; based on the first detection power factor and the first detection load resistance, the load short-circuit state of the charging pile is determined, and the load short-circuit state comprises a normal load and a short-circuit load. According to the invention, the stability and reliability of the short-circuit detection result can be improved.

The invention belongs to the field of integrated circuit power supply chip design, and particularly relates to an overshoot and undershoot suppression transient enhancement circuit applied to an LDO (Low Dropout Regulator), which consists of a band-gap reference circuit, an error amplifier, a power tube PMOS (P-channel Metal Oxide Semiconductor) tube MP1, a second-stage amplifier tube NMOS (N-channel Metal Oxide Semiconductor) tube MN1, a resistor R4, a load resistor RL and an on-chip load capacitor CL, the self-adaptive zero point module consists of a resistor R3, a capacitor C1 and an NMOS (N-channel Metal Oxide Semiconductor) tube MN2, the LDO feedback network consists of a resistor R1 and a resistor R2, and the module is used for inhibiting output voltage uprush and downrush. According to the invention, through the upshoot suppression circuit and the undershoot suppression circuit, effective suppression of upshoot and undershoot generated during load sudden change is realized, the recovery time of upshoot and undershoot voltage is shortened, and the upshoot suppression circuit only generates a small amount of quiescent current consumption; the undershoot suppression circuit does not generate extra static consumption under the whole LDO working state due to the effect of the capacitor.

The invention provides a low-noise amplifier and a low-noise amplifier system. The low-noise amplifier comprises a signal input module, a switching tube module and a load module, the switch tube module is connected with the signal input module and the load module. The load module comprises a load inductor, a load capacitor and an adjustable load resistor which are connected in parallel; wherein the adjustable load resistor is used for adjusting the gain and flatness of the low-noise amplifier; the signal input module is used for providing an input signal for the switching tube module; and the switching tube module is used for outputting an output signal of the low-noise amplifier based on the input signal and the load module. According to the low-noise amplifier, variable gain and variable flatness can be achieved through the adjustable load resistor, the low-noise amplifier can adapt to different modes of different gains and different flatness only by adjusting the resistance value of the adjustable load resistor, and therefore the application scene of the low-noise amplifier can be expanded.

The utility model discloses a calibration device for a track circuit dynamic detection system, and relates to the technical field of track circuit dynamic detection. The device comprises a signal source module, a power amplifier, a load resistor and an ampere meter, the controller outputs a control signal to the signal generator; the signal generator outputs a current signal to the gain regulator based on the control signal; the gain regulator outputs the current signal after gain regulation to the power amplifier based on the current signal; the power amplifier outputs an amplified current signal to the load resistor based on the current signal after gain adjustment; according to the utility model, the precision and the stability of the output current signal can be improved, and the stability, the accuracy and the efficiency of the calibration of the track circuit dynamic detection system can be improved.

The embodiment of the invention discloses a washing machine control method and device, electronic equipment and a computer readable storage medium. The method comprises the steps that a first position and a second position are determined, the first position is the position of a current inner barrel, and the second position is the position of a current outer barrel; determining a first anti-eccentricity value according to the first position and the second position, wherein the first anti-eccentricity value is used for representing the unbalanced load resistance in the current washing machine operation process; determining a dehydration coefficient of the washing machine, wherein the dehydration coefficient is used for adjusting rotation speed of the washing machine during dehydration; and determining the rotating speed of the washing machine according to the first anti-eccentricity value and the dehydration coefficient. According to the washing machine control method, the eccentricity condition of the washing machine can be accurately judged according to the positions of the inner barrel and the outer barrel, the rotating speed of the washing machine in the dewatering operation stage is adjusted according to the eccentricity condition, and therefore the technical effect of avoiding collision between the inner barrel and the outer barrel of the washing machine is achieved.

The utility model discloses a multi-range current acquisition circuit, which comprises a load current acquisition circuit and a current bypass circuit, the load current acquisition circuit is connected in series between a power supply and a load resistor RX, and the current bypass circuit is connected in parallel with one side of the load current acquisition circuit. According to the utility model, the current bypass circuit is designed to be connected in parallel with one side of the load current acquisition circuit, so that current acquisition is not influenced after normal switching of the load current acquisition circuit, and a new current path can be provided when the acquisition circuit is not switched so as to ensure that the load at the output end can work normally.

The invention discloses a DSEG system HBSCR fault diagnosis method based on bus current, and relates to the field of H-bridge half-controlled rectifiers. According to the method, a current sensor is additionally arranged on a bus positive electrode between equipotential connecting ends of three left bridge arms and equipotential connecting ends of three right bridge arms in an HBSCR; a current sensor is additionally arranged on a bus positive electrode between equipotential connecting ends of three right bridge arms and a positive electrode of a load resistor, and fault detection is realized by combining the current characteristic combination of a last group of current sampling values before the end position of a working interval of each sector and a first group of current sampling values after the end position of the working interval. The method is simple in implementation mode and small in calculation amount, and makes up the technical vacancy of the industry. And the method is not influenced by rotating speed or load change, is not influenced by a fault occurrence position, and is wide in applicability.

The invention provides a PT symmetry-based hybrid coupling wireless power transmission system with controllable output power. The output power can be adjusted while the high anti-offset characteristic is maintained. In the system, the stable output of the system when a coupling mechanism deviates is realized by enabling the system to be in a PT symmetrical state, and meanwhile, the power and efficiency of the stable output of the system are changed by changing the ratio of the reciprocal of series inductors in an LL type compensation network of a receiving end to the sum of the reciprocals of the two inductors. Compared with a common hybrid coupling wireless power transmission system, the hybrid coupling wireless power transmission system has the advantage that the output power and efficiency can be adjusted under the conditions that the system keeps high offset resistance and the load resistance and the input voltage of the system are not changed.

The invention discloses a rapid soft start control method and device for a switching power supply. The method comprises the following steps: determining a target voltage output by a soft start preprocessing circuit in a steady state according to a preset standard voltage, a preset standard current and a load resistance value of a resistive load; determining a target duty ratio corresponding to a switching tube of the soft start preprocessing circuit in a steady state according to the target voltage and a preset input voltage of the switching power supply; a first control signal is sent to the pulse width modulation circuit, and the duty ratio of the switching tube is adjusted to the maximum duty ratio; monitoring that the real-time output voltage of the soft start preprocessing circuit is increased to the target voltage through a voltage sampling circuit; and a second control signal is sent to the pulse width modulation circuit, and the duty ratio of the switching tube is adjusted from the maximum duty ratio to the target duty ratio, so that rapid soft start of the switching power supply is realized and a steady state is reached. According to the invention, the soft start time of the switching power supply can be obviously shortened, and the switching power supply can rapidly reach a stable working state after soft start.

The invention discloses a high-efficiency monolithic integrated balanced power amplifier, relates to the field of amplifiers, and aims to solve the problems that a coupling line used by an existing low-frequency lane bridge is relatively long and often exceeds the size of a power amplifier chip, the lane bridge can be integrated on a chip only after being coiled, and relatively high line loss is brought by the relatively long coupling line, so that the loss of the low-frequency lane bridge is relatively large, and the cost is relatively high. According to the technical scheme, the balance type power amplifier solves the problems that on one hand, the output power of the amplifier is reduced, on the other hand, the power capacity of a lange bridge is also limited, and the thickness of a monolithic integrated balance type power amplifier chip is determined by the technology and cannot be increased at will. The balance type power amplifier comprises a low-loss lange bridge circuit and a power amplifier sub-circuit; the number of the low-loss lange bridge circuits is two, the number of the power amplifier sub-circuits is two, the number of the low-loss lange bridge circuits is two, the number of the power amplifier sub-circuits is two, the low-loss lange bridge comprises parallel coupling lines, a load resistor and a capacitor, the number of the parallel coupling lines is two, each of the two parallel coupling lines is formed by arranging two or four coupling lines in parallel, and two adjacent ports of the two parallel coupling lines are connected in a pairwise crossing mode.

The invention relates to the technical field of output control, in particular to a constant power control method, device and equipment based on COT and a storage medium, according to the method, fixed turn-on time is combined with dynamic turn-off time adjustment, the conciseness of COT control is reserved, accurate control over output power is achieved, and the control efficiency is improved. The influence of interference factors such as battery voltage drop and load abrupt change on constant power output can be effectively counteracted; specifically, a multi-path output synchronous opening design is adopted, and unified turn-off time adjustment logic is combined, namely, the turn-off time of a (k + 1) th period is calculated according to the total duration of a target period, so that an asynchronous turn-off condition caused by parameter differences of all channels is avoided, and the voltage rise deviation generated by load changes of a later turn-off channel is reduced; real-time output voltage and load resistance are respectively sampled in one period, battery voltage fluctuation and load change are monitored in real time, and error accumulation caused by the fact that a measured value in the current period is extended to the next period to be adjusted is avoided.

An LKYLEU-TH type ground electronic unit LEU automatic test system relates to the railway signal equipment detection application technology field and comprises an industrial control computer, a relay switching module, a programmable power supply, an active transponder, a transponder read-write tool, an oscilloscope, an analog communication module, a load resistor and an external storage server. The industrial control computer is connected with the analog communication module, the analog communication module is connected with the tested ground electronic unit LEU, the industrial control computer is connected with an input terminal of the relay switching module, an output terminal of the relay switching module is connected with the load resistor and the active transponder, and the relay switching module is connected with the tested ground electronic unit LEU. The relay switching module is connected with the oscilloscope. According to the invention, the function and performance test of the LKY.LEU-TH type ground electronic unit LEU in the production process is realized.

A touch display module comprises a first electromagnetic touch signal loop and a second electromagnetic touch signal loop, the first electromagnetic touch signal loop and the second electromagnetic touch signal loop generate a first induction current and a second induction current, and the length of the first electromagnetic touch signal loop and the length of the second electromagnetic touch signal loop are small. The overall time length of one-time point reporting can be shortened, and the load resistance of the first electromagnetic touch signal loop and the load resistance of the second electromagnetic touch signal loop are small. Under the condition that the load resistance is reduced, the first driving current and the second driving current are large, the electromagnetic induction potential of the electromagnetic pen is large, the first induction current and the second induction current are large, the strength of a touch induction signal can be improved, the point reporting precision of a screen is high, the charging time of the electromagnetic pen can be shortened, and the user experience is improved. And the touch effect of the electromagnetic pen is relatively good. The invention further provides a display device comprising the touch display module.

The invention relates to the technical field of amplifiers, in particular to a variable gain amplifier with a wide linear gain range and a working method, and the variable gain amplifier comprises the steps that a linear gain generation circuit receives a differential input signal and provides gain-adjustable differential output based on linear control voltage; the linear gain generation circuit comprises at least one stage of variable gain unit which comprises differential input pair transistors MN1 and MN2. The load resistor elements R1 and R2 are connected between the power supply voltage VDD and the drain electrodes of the differential input pair transistors MN1 and MN2; the tail current source MN3 provides bias current for the differential input pair transistors MN1 and MN2; the active load network is connected between the drain electrodes of the differential input pair transistors MN1 and MN2 and the ground; the active load network comprises a control tube MN8, the control tube MN8 works in a sub-threshold region, a grid electrode receives linear control voltage, equivalent impedance of the active load network is enabled to be in exponential change along with the linear control voltage through exponential I-V characteristics, and dB linear gain adjustment of the variable gain unit is achieved.

The embodiment of the invention provides a DC / DC boost converter based on a charge pump, a chip and energy storage equipment. The DC / DC boost converter based on the charge pump comprises a switch controller, a pre-stage main circuit and a post-stage charge pump circuit, wherein the pre-stage main circuit and the post-stage charge pump circuit are connected in parallel in an interleaving manner; the pre-stage main circuit comprises a rechargeable battery, a first inductor, a second inductor, a first switch and a second switch; wherein the source electrode of the first switch is connected with the post-stage charge pump circuit; the source electrode of the second switch is connected with the post-stage charge pump circuit; the post-stage charge pump circuit comprises a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first diode, a second diode, a third diode, an output diode, a load capacitor and a load resistor; the switch controller is connected with the source electrode of the first switch and the source electrode of the second switch in the front-stage main circuit so as to provide switch control signals for the first switch and the second switch, control the switching states of the first switch and the second switch and control the output voltage in the rear-stage charge pump circuit, and therefore high-gain boosting is achieved based on the small duty ratio.

The utility model provides a leakage current automatic testing device of a proximity switch, and relates to the field of proximity switch testing. The tested device is connected with a power supply positive electrode and a power supply negative electrode of the power supply; and the testing device is connected with the switch output of the tested device and is connected with the power supply. The utility model provides an automatic leakage current testing device for a proximity switch, and solves the problem that a digital potentiometer cannot be directly used for replacing a power load resistor for testing.

The invention relates to the technical field of testing and application of power semiconductors, in particular to a SiC MOSFET gate oxide reliability testing device and method, and the device is provided with a high-voltage direct-current voltage power supply, an auxiliary direct-current voltage source, a signal generation device, a half-bridge testing circuit, a gate drive circuit, a load inductor, a load resistor and measuring equipment. According to the method, the stress time required for evaluating the reliability of the device can be remarkably shortened, meanwhile, the threshold voltage drift characteristics of the device under different drain-source voltage stresses can be more accurately described, compared with a traditional static bias and grid switch stress test method, the influence of dynamic drain-source voltage and current is effectively introduced, the accuracy of a model test result is improved, and the reliability of the device is improved. The method has a certain application value for evaluating the reliability of the gate oxide layer of the SiC MOSFET.

The invention relates to the technical field of grounding detection and maintenance, in particular to a multipoint grounding online monitoring device and a fault monitoring method. The current detection unit is used for detecting current signals in the grounding wire and the zero line grounding wire; the signal processing unit is used for filtering the current signal output by the current detection unit; the control unit determines the presence of a multi-point ground fault. If the amplitude of the grounding wire current signal exceeds a preset threshold value, a multi-point grounding fault exists; if the current signal has an abnormal frequency component, a multi-point grounding fault exists; current signals have phase differences, and multi-point grounding faults exist. And an unbalanced load resistor is connected, and if no current is detected in the grounding wire, a multi-point grounding fault exists. On-line monitoring of PT multipoint grounding faults is achieved under the condition that system operation is not affected. Manual inspection is replaced, PT multipoint grounding faults are found and alarmed in time, the working efficiency and safety are improved, two detection methods of a zero line current method and an unbalanced load current method are provided, and the requirements of different scenes are met.

The invention provides a static frequency divider with adjustable self-resonant frequency and a clock circuit, and relates to the technical field of circuits, the frequency divider comprises a master latch and a slave latch; each of the master latch and the slave latch comprises a current source, an adjustable resistor unit, a differential amplification pair, a cross coupling pair and a load resistor pair; the current source is connected with the first current branch and the second current branch, the first current branch is connected with the load resistor pair through the differential amplification pair, the second current branch is connected with the load resistor pair through the cross coupling pair, the first current branch is provided with a first switching tube, and the second current branch is provided with a second switching tube and an adjustable resistor unit which are connected in series. Thus, the adjustable resistor unit is configured on the second current branch, association between the resistance value of the adjustable resistor unit and the frequency of the frequency divider is established, a hardware basis is provided for frequency adjustability, and frequency requirements of different scenes are met by adjusting the resistance value of the adjustable resistor unit and adjusting the self-resonant frequency of the frequency divider.

The utility model belongs to the technical field of test equipment, and discloses portable alternating current charging pile test equipment, which comprises an alternating current charging pile tester, and a charging gun socket, a test circuit board and a load resistor are arranged on one side in the alternating current charging pile tester. The test circuit board comprises an AD sampling circuit and an ARM processor electrically connected with the AD sampling circuit. The AD sampling circuit is composed of a clamp voltage circuit, a measurement reference circuit, an LN voltage sampling circuit, an LN current sampling circuit, a CP voltage sampling circuit, a PWM waveform sampling circuit, a CC resistance sampling circuit, an AD data acquisition circuit and a test process control circuit. According to the utility model, all functions of testing the alternating current charging pile can be integrated on one testing device, the functions are comprehensive, the device is convenient to carry, and the device can be used for testing on a factory production line, can also be carried about, and is used for testing the charging pile on a charging pile working site.