Abstract: A signal transmission circuit board includes a main body and a first connecting unit connected with the main body. The first connecting unit includes a test pin area and an avoidance area adjacent to the test pin area, and the avoidance area is free of test pins.

Abstract: The present invention relates to conductor connection system for a wind turbine lightning protection system adapted to protect a wind turbine blade from lightning strikes. The lightning protection system comprises a down conductor cable adapted to extend in a longitudinal direction of the wind turbine blade and arranged for connection to the root end of the wind turbine blade, and comprises a number of lightning receptors electrically connected to and distributed along the length of the down conductor cable. The down conductor connection system comprises a modular down conductor cable having a first and second down conductor cable part, and at least one down conductor connector arranged between and connected to the ends of the down conductor cable parts. The down conductor connector comprises first and second terminals, connected to an end of each down conductor part, respectively, where the first and second terminals are adapted for mutual connection.

Abstract: The present disclosure relates to a motor vehicle on-board network with a first voltage circuit for supplying electric power to an environment sensor system with a first electrical voltage, wherein an insulation monitor is provided for the first voltage circuit to monitor the insulation resistance of the first voltage circuit.

Abstract: The presented invention relates to a method for monitoring an insulation state of a first high-voltage network and an insulation state of at least one further high-voltage network of a vehicle, wherein a single insulation monitor is connected to the first high-voltage network and to the at least one further high-voltage network, and wherein, by means of the insulation monitor, a first insulation measurement, initially, is carried out, in a periodically repeated sequence, on the first high-voltage network, and, then, a further insulation measurement is carried out in each case on the at least one further high-voltage network.

Abstract: Provided is an electronic control device, including: a plurality of grounding terminals provided to a plurality of grounds in the device individually on a one-to-one basis; a grounding common portion for connecting a plurality of grounding points provided to the plurality of grounds individually on a one-to-one basis; a current detection unit configured to detect each of currents flowing between the plurality of grounding points and the plurality of grounding terminals provided for the plurality of grounding points individually on a one-to-one basis or a current flowing through the grounding common portion; and a controller configured to detect a ground open condition for each of the plurality of grounds by comparing a detection result obtained by the current detection unit with a determination value for determining the ground open condition.

Abstract: Systems and methods are configured for detecting and locating simultaneous faults in a distribution network having primary and secondary buses connected with two-terminal sections. The measured three-phase voltages and currents from the primary buses are received via a communication network, and the series impedances and shunt admittances and the pre-fault connectivity topology are retrieved from the storage. Simultaneous faults are determined to occur by verifying at least one phase of at least three buses having phase current mismatches determined as the differences between the measured values and calculated values using normal topology and phase voltages that are greater than a threshold. A location for each fault is determined individually if the faults are occurring at non-adjacent sections in the distribution network, or jointly if the faults are occurring at adjacent sections in the distribution network.

Abstract: The present disclosure provides an insulation detection circuit and method, and a battery management system. The circuit includes a first isolation module, a voltage division module, a signal generation module, first and second sampling points and a processor. A first end of the first isolation module is connected to a power battery, and a second end of the first isolation module is connected to the second sampling point. The signal generation module is connected to the first sampling point and configured to inject an AC signal into the power battery and provide the first sampling point with a first sampled signal. A first end of the voltage division module is connected to the first sampling point, and a second end of the voltage division module is connected to the second sampling point. The processor is configured to calculate an insulation resistance of the power battery.

Abstract: The invention relates to a method for producing a valve (1) that can be electromagnetically actuated which method comprises an electromagnet (2, 2a, 2b), an armature (3) that can be moved by the electromagnet (2, 2a, 2b), and a valve body (5), having means (4, 4a, 4b, 4c) for converting a movement of the armature (3) into an opening or closing of the valve (1), wherein the electromagnet (2, 2a, 2b) and the armature (3) are inserted into the valve body (5), wherein, before the electromagnet (2, 2a, 2b) is inserted into the valve body (5), a magnetic hysteresis curve (10) of a combination (6) of the electromagnet (2, 2a, 2b) having a test armature (3a) lying against said electromagnet (2, 2a, 2b) is recorded, the slope m1 of a first, substantially linear curve segment (11) of the hysteresis curve (10) is determined in the unsaturated state, and, from the slope m1, the slope m1* of a curve segment (31) of a hysteresis curve (30) of the finally assembled valve (1) having the armature (3) lying continuously agains

Abstract: The present disclosure provides an insulation detection circuit and method, and a battery management system. The circuit includes a first isolation module, a voltage division module, a signal generation module, first and second sampling points and a processor. A first end of the first isolation module is connected to a power battery, and a second end of the first isolation module is connected to the second sampling point. The signal generation module is connected to the first sampling point and configured to inject an AC signal into the power battery and provide the first sampling point with a first sampled signal. A first end of the voltage division module is connected to the first sampling point, and a second end of the voltage division module is connected to the second sampling point. The processor is configured to calculate an insulation resistance of the power battery.

Abstract: Embodiments disclosed herein are directed towards systems and methods for electric current leakage detection in a land seismic system. Embodiments may include generating at least one test signal using a digital to analog converter “DAC” circuitry, wherein the DAC circuitry includes an output operatively connected to earth ground. Embodiments may further include alternately grounding a positive path to an analog to digital converter “ADC” circuitry during a first time window and a negative path to the analog to digital converter during a second time window while measuring an ADC signal. Embodiments may also include determining an average amplitude of the first time window and the second time window and determining a leakage resistance based upon, at least in part, the average amplitude of the first time window and the second time window.

Abstract: A mobile tester is provided for “Very Low Frequency” (VLF) testing of a measurement object, which has means for generating an AC voltage which has an effective amplitude of greater than or equal to 1 kV and a frequency in the range of between 0.01 and 1 Hz, a connection element for connecting the measurement object, and means for measuring and evaluating the test voltage applied to the measurement object and the test current caused thereby. In a first operating mode, the tester autonomously carries out a VLF test using the test voltage generated. The tester also has a communication interface for emitting a synchronization signal or for receiving an externally generated synchronization signal, and the tester is set up, in a second operating mode, to synchronize the generated test voltage with the test voltage generated by at least one further tester of the same type.

Abstract: An EMS training device includes an EMS stimulus generating unit for generating EMS stimuli following a specified excitation pattern with current pulses and/or an alternating current. EMS electrodes are attached to a living body in pairs for applying the EMS stimuli to the body. Line branches connect the EMS electrodes to the EMS stimulus generating unit to apply the EMS stimuli to corresponding EMS electrodes such that a current with a specified amplitude and frequency pattern is conducted through the body. To protect the EMS electrodes and/or other susceptible elements of the line branches from corrosion, the EMS training device has at least one measuring device for measuring a value of a resistance in the line branch, a comparison device for comparing the value with a target value, and at least one compensation device for compensating for a deviation of the actual value from the target value.

Abstract: An electronic apparatus is obtained that suppresses a decrease in convenience to a legitimate user while reducing the possibility of unauthorized login. In the electronic apparatus, a user-interface unit displays a user-authentication screen, and detects operation for confirming a character string that is inputted in an input field. The user-authentication unit, when this operation is detected, executes user authentication based on the character string that is inputted in the input field and a pre-registered password. The user-authentication unit considers user authentication as having failed at least one time even though the character string is a correct password. The user-interface unit, (a) when the character string is not a correct password and user authentication has failed, clears the character string that is inputted in the input field. Then the user-interface unit monitors whether or not user operation of an operation unit or re-input of a character string in the input field is detected.

Abstract: An electric-motor-control system with current sensor offset correction includes three current-sensors and a controller. Each of the three current-sensors is used to detect current through one of three windings of a Y-connected motor. The controller is in communication with the three current-sensors. The controller records periodically measurements of sensed-current indicated by each current-sensor while variable-current flows through each of the three windings, determines an x-offset and a y-offset of a rotating-vector indicated by a plurality of the measurements, and determines an offset-current of each of the three current-sensors based on the x-offset and the y-offset.

Abstract: The invention relates to a DC power distribution system (1) comprising a power supply (50) for supplying DC power to an electrical device (11) like a luminaire, wherein the system includes a connection device (4) comprising a connection device contact (5) to which an electrical device contact (19) of the electrical device is to be connected, a load presence detection unit (7) for detecting whether the electrical device contact has been connected, and a power providing control unit (6) for providing the DC power of the DC power distribution system to the connection device contact, only if the load presence detection unit has detected that the electrical device contact of the electrical device has been connected to the connection device contact. Thus, a voltage is not applied to the connection device contact, if the electrical device is not connected, thereby reducing corrosion effects and the likelihood of installers getting electrified.

Abstract: A method and system are disclosed for detecting turn-to-turn and phase-to-phase winding short circuits in an electric motor. The motor is tested at a standstill condition by injecting a current signal into the virtual d-axis of the motor while controlling q-axis current to zero. Steady state feedback current from the motor is measured, and current harmonics are calculated using FFT or peak-to-peak techniques. It is determined that a short circuit is present in the winding if feedback current harmonics higher than a nominal level are detected, where the increased feedback current is an indication that winding inductance has decreased due to a short circuit. Testing at standstill using a small current advantageously prevents the possibility of damaging the motor and avoids inductance variation due to changing rotor position.

Abstract: A system and method are provided for implementing an automated scheme for consistently confirming completion of repair and post-repair operating parameters for a heating, ventilation and air conditioning (HVAC) system to improve consistency of diagnostic analyzes, services provided by available or pre-selected HVAC repair facilities or contractors and confirmation of repair services performed by those HVAC repair facilities or contractors. A system-based automated solution is provided for confirmation of completion and efficacy of repairs in HVAC systems. HVAC system and component operations are confirmed to be within specified ranges.

Abstract: The invention relates to an apparatus for insulation monitoring between a low-voltage supply system and a high-voltage supply system, wherein the apparatus can be connected both to a high-voltage positive connection and also to a high-voltage negative connection and also to the low-voltage supply system, wherein the apparatus has a plurality of electrical contacts for coupling monitoring connections to the high-voltage circuit by means of a respective high-voltage positive connection and by means of a respective high-voltage negative connection, it being possible for said contacts to be connected in different sections of the high-voltage supply system.

Abstract: The present disclosure pertains to systems and methods for monitoring a plurality of analog-to-digital converters. In one embodiment, a plurality of input channels may each be in communication with a different phase of a three-phase electric power delivery system. The input channels may be configured to receive analog signals from the different phases. A composite signal subsystem may be configured to generate a composite signal based on the plurality of input channels. An analog-to-digital converter subsystem may be configured to produce a digitized representation of each of the plurality of input channels and a digitized representation of the composite signal. An analog-to-digital converter monitor subsystem may identify an error in the analog-to-digital conversion based on the digitized representation of the composite signal and the digitized representations of the plurality of input channels.

Abstract: A method for identifying electrical faults in a generator assemblage, in particular of a motor vehicle, which assemblage includes a generator having a generator regulator and a rectifier having rectifier elements, the method encompassing ascertaining, in the context of at least one excitation current value of an excitation current through an excitation winding of the generator, at least one respective parameter that corresponds to a current conduction time proportion of at least one of the rectifier elements, and determining that an electrical fault exists if the at least one parameter deviates by more than a predetermined amount from an associated expected value. Also described is an apparatus for implementing the method.

Abstract: In an electrical cord reel, a rotatable member can rotate about a winding axis to spool and unspool a linear material. An input power connector can couple to an electrical power source. An output power connector on the rotatable member can couple to an electrical cord at least partially wound about the rotatable member. A switch is adjustable to allow or prevent electrical current flow from the input power connector to the output power connector. In an aspect, the electrical cord reel includes an electric cord comprising a first power wire, a second power wire, and a signal wire. A method of controlling the electric cord spool system includes energizing the first power wire and the signal wire. The method further includes determining a continuity of the signal wire. The method further includes de-energizing the first power wire when determining discontinuity of the signal wire.

Abstract: An air-cooled dynamo-electric machine, in particular an enclosed-ventilated dynamo-electric machine includes a stator with a winding system which forms end windings at the end faces of the stator. At least the end winding has at least one monitoring element in its insulation layer, or in an additional layer which is applied to this insulation layer, for the purpose of monitoring the insulation thickness of the end winding.

Abstract: A system and method for testing a beverage apparatus such as a beverage maker and/or dispenser before shipment. The beverage apparatus includes at least one component that can produce monitorable and/or measurable characteristic. The measurable characteristic may be compared against a threshold value and may include an acceptable tolerance range. In response to an out-of tolerance condition, a fail condition is displayed, otherwise a pass condition is displayed. Also disclosed is a system for storing the measurable characteristic so that the beverage apparatus can be analyzed by comparing its current state versus the baseline state measured before the beverage apparatus was shipped.

Abstract: A load detecting method relates to detecting connection or detachment between a power supply device and a load, and the load detecting method includes steps of determining whether a load detection operation is necessary or not, based on a detection voltage corresponding to an output voltage from the power supply device, when determining the load detection operation to be necessary, estimating a specific time point in a first period during which the output voltage of the power supply device decreases from a first level to a second level, and applying a test signal to the output voltage for a predetermined detection period with reference to the specific time point. The switching operation of a power switch of the power supply device does not occur in the first period.

Abstract: A system and method for discharging a high voltage vehicle battery. The system includes a discharge circuit having a reference voltage source providing a reference voltage and a load for discharging the battery. A negative terminal of the voltage source is electrically coupled to a negative terminal of the battery so that upon initiation of the discharging sequence, the battery is discharged through the load to the reference voltage. The discharge circuit can be electrically configured so that the battery, the voltage source and the load are electrically coupled in series or the battery, the voltage source and the load are electrically coupled in parallel.

Abstract: A security device comprises a mounting plate and a mounting device. The mounting plate, for being fixed to a surface, comprises a first electrical contact point and a second electrical contact point electrically connecting to the first electrical contact point. The mounting device is to be assembled to the mounting plate and comprises a third electrical contact point, a fourth electrical contact point and a detection circuit. The third electrical contact point is for contacting the first electrical contact point when the mounting device is assembled to the mounting plate. The fourth electrical contact point is for contacting the second electrical contact point when the mounting device is assembled to the mounting plate. The detection circuit is electrically connected to the fourth electrical contact point, for determining whether the fourth electrical contact point is electrically connected to the third electrical contact point.

Abstract: A street light cable anti-theft system includes a front-end control device, a signal control device and an information processing terminal. The front-end control device is disposed within a street light control box for applying a voltage signal to a street light cable when a street light is switched off. The signal control device is installed on a lighting pole of a last street light of a public lighting circuit for detecting a voltage signal of the street light cable, determining a state of the street light cable based on the obtained voltage signal, and sending the state signal to the information processing terminal. The information processing terminal is adapted for receiving and processing the state signal sent by the signal control device. The anti-theft system has some advantages of timely obtaining the information of the cable, low maintenance cost, not being affected by power failure and high reliability.

Abstract: In a process plant, a first series of measurements from a coupling interface are received. The first series of measurements are stored. A second series of measurements from a coupling interface are received. The second series of measurements. The first series and second series of measurements are compared. An indication of loss of clamping force is generated if the first series of measurements deviates from the second series of measurements.

Abstract: A system includes a plurality of sensors configured to detect an electrical voltage and an electrical leakage current associated with an operation of an industrial machine, and a controller including a processor and a selection device. The selection device is configured to receive from the plurality of sensors a first input corresponding to the electrical voltage, and a second input corresponding to the electrical leakage current. The first input is paired with the second input to generate a paired input. The selection device is configured to transmit an output to the processor based at least in part on the paired input. The output includes an indication of the electrical leakage current or a dissipation factor associated with the industrial machine.

Abstract: In at least one embodiment, provided is an electric vehicle supply equipment having a line power contactor including a first line power input and a second line power input and a first line power output and a second line power output. It further has a welded contactor detector with a contactor sense circuit, the sense circuit having a first line shunt resistor network connected from the first line power contactor output to ground and a second line shunt resistor network connected from the first line power contactor output to ground. In another embodiment provided is an EVSE including a welded contactor detector with a contactor sense circuit having a bias resistor connected between the hot line relay input and the neutral line relay output.

Abstract: In a rotating electrical machine, a conductive foil or conductive rubber is applied to the surface of insulation layer of a conductor series connection area or to the surface of insulation layer of a turn conductor of coils of rotating electrical machine winding, waveforms of grounding voltages of the individual turn conductor portions are measured through the medium of an electrostatic capacitance of the insulation layer of coil conductor series connection area or through the medium of the insulation layer of coil turn conductor, and a partial discharge is measured while measuring a voltage developing in the coil or across a winding turn in the coil from a difference between the waveforms of grounding voltages.

Abstract: A method for enhancing the reliability of generator ground fault detection based on a signal injection scheme, wherein the generator includes a winding. The method includes injecting a test signal at a predefined frequency to the winding, measuring an electrical quantity of a response signal in the winding resulted from the injected test signal, and detecting a ground fault based on the measured value of the electrical quantity. The method further includes continuously determining the frequency of the response signal, and discarding the present measured value corresponding to the determined frequency when the determined frequency deviates from the predefined frequency with a first threshold value.

Abstract: An instrument test arrangement is specified, which is preferably equipped for medical instruments for argon plasma coagulation. The instrument test arrangement comprises an electrode arrangement, comprising at least one test electrode. In a preferred embodiment, a test electrode is thereby connected to two neutral conductors of a neutral conductor cable or device, wherein the neutral conductors are insulated from one another, and wherein the first coupling impedance between the test electrode and the first neutral conductor and the second coupling impedance between the test electrode and the second neutral conductor are equal or at most slightly different, so that a split circuit, which is assigned to a neutral electrode arrangement, does not trigger due to the strike of a test spark or arc.

Abstract: A circuit integrity detection system for use in detecting the integrity of a sensing wire in a heating pad wherein the integrity of the sensing wire is checking the inputs from a first and second A/D converter connected to opposite ends of the sensing wire.

Abstract: A testing device and a testing method are provided. The testing device includes a connecting module and a processor electrically connected to the connecting module. The connecting module is electrically coupled with a plurality of communication devices under tests (DUTs) synchronously. The processor determines a schedule for the communication DUTs and tests the communication DUTs according to the schedule. The testing method is applied to the testing device to implement the aforesaid operations.

Abstract: In a process plant, a first series of impedance measurements from a valve body are received. The first series of impedance measurements are stored. A second series of impedance measurements from the valve body are received. The second series of impedance measurements from the valve body are stored. The first series and second series of impedance measurements are compared. An indication of loss of integrity of the valve body is generated if the first series of impedance measurements deviates from the second series of impedance measurements.

Abstract: In an electrical cord reel, a rotatable member can rotate about a winding axis to spool and unspool a linear material. An input power connector can couple to an electrical power source. An output power connector on the rotatable member can couple to an electrical cord at least partially wound about the rotatable member. A switch is adjustable to allow or prevent electrical current flow from the input power connector to the output power connector. In an aspect, the electrical cord reel includes an electric cord comprising a first power wire, a second power wire, and a signal wire. A method of controlling the electric cord spool system includes energizing the first power wire and the signal wire. The method further includes determining a continuity of the signal wire. The method further includes de-energizing the first power wire when determining discontinuity of the signal wire.

Abstract: A magnetic flowmeter includes a flowtube arranged to receive a flow of process fluid. A coil is positioned proximate the flowtube and arranged to apply a magnetic field to the process fluid in response to a drive current alternating direction. First and second electrodes are arranged to sense a voltage potential in the process fluid in response to the applied magnetic field. The voltage potential is indicative of flow rate of process fluid through the flowtube. A sensor is coupled to the first and second current paths which has a sensor output related to the drive current. Diagnostic circuitry provides a diagnostic output as a function of a transient change in the sensor output when current flowing through the coil alternates direction.

Abstract: A control device is connectable to a surgical instrument, and controls the surgical instrument. When the surgical instrument is connected, the control device determines the quality of the surgical instrument by performing a plurality of different tests.

Abstract: A system and method for detecting excess voltage drop (EVD) in a three-phase electrical distribution circuit includes a diagnostic system comprising a processor that is programmed to receive three-phase voltages and currents provided to terminals of the electrical machine, determine fundamental components of the three-phase voltages and currents provided to the terminals, and compute positive, negative, and zero sequence currents from the fundamental components.

Abstract: The present invention relates to a magnetic sensor that provides the sensitivity adjustment on a wafer and that has a superior mass productiveness and a small characteristic variation. The magnetic sensor includes a magnetic sensitive portion provided on a substrate that is made of a compound semiconductor and that has a cross-shaped pattern. This magnetic sensitive portion includes input terminals and output terminals. At least one of input terminals of the input terminal is series-connected to a trimming portion having a compound semiconductor via a connection electrode. By performing laser trimming on the trimming portion series-connected via the connection electrode to the magnetic sensitive portion while performing a wafer probing (electric test), the adjustment of the constant voltage sensitivity is provided.

Abstract: An abnormality monitoring system includes: an electronic component that outputs a lock signal of “High” when the electronic component stops functioning and outputs a lock signal of “Low” when the electronic component functions; a signal device that supplies power to the electronic component and outputs an ON operation signal instructing the electronic component to function and an OFF operation signal instructing the electronic component to stop functioning; a harness member that connects the electronic component and the signal device and transmits and receives a signal; and a monitor device that determines abnormality of the electronic component when the operation signal is ON and the lock signal is “Low”, and determines abnormality of the harness member when the operation signal is OFF and the lock signal is “Low”.

Abstract: In a method for testing signal integrity of an electronic product using a signal integrity test apparatus, each electronic component of the electronic product includes a test label that identifies the electronic component. The signal integrity test apparatus includes a host computer, a robot device, an oscilloscope, a camera device, and a probe. The host computer is installed with a signal integrity test system that controls the signal integrity test apparatus to test signal integrity of the electronic product. The robot device includes a first robot arm and a second robot arm. The first robot arm controls the camera device to capture an image of the test label coupled to each electronic component. The second robot arm controls the probe to touch each electronic component. The oscilloscope measures voltage signals outputted from the electronic components to generate a signal integrity report of the electronic product.

Abstract: A coil detection circuit thereof for an electromagnetic input device including a plurality of first loop coils and second loop coils includes a first detection unit, a second detection unit and a selection unit. When the selection unit selects one the first loop coils to emit an electromagnetic signal for each one of the second loop coils, each one of the second loop coils forms a second closed loop for receiving the electromagnetic signal, and the second detection unit detects a second signal. When one of the second loop coils forms an open circuit or short circuit, the second detection unit detects an open-circuit signal or a short-circuit signal.

Abstract: A circuit integrity detection system for use in detecting the integrity of sensing wire in a heating pad wherein the integrity of the sensing wire is checking the inputs from a first and second A/D converter connected to opposite ends of the sensing wire.

Abstract: This disclosure relates to delay line test circuits and methods. In one aspect, an integrated circuit (IC) can include a plurality of delay lines, a selection circuit, a delay comparison circuit, and a control circuit. The plurality of delay lines can generate a plurality of delayed clock signals, and the selection circuit can include a plurality of inputs configured to receive at least the plurality of delayed clock signals. The selection circuit can generate a first output clock signal and a second output clock signal by selecting amongst signals received at the plurality of inputs based on a state of a selection control signal. The delay comparison circuit can compare a delay of the first output clock signal to a delay of the second output clock signal and can generate a delay comparison such as a pass/fail flag based on the result. The control circuit can generate the selection control signal.

Abstract: The present invention is an efficient high voltage sensing mechanism that operates only when an individual needs to test the voltage across a wire. The present invention attaches around a tested wire using a jaw and a hook. The hook is tensioned using an expansion spring. The operator propels the hook outwards from the jaw, around the tested wire; thereafter, the expansion spring retracts to latch onto the tested wire against the jaw. An on-off switch is integrated into the mechanical hook device. As the hook is propelled outwards, the on-off switch moves into the “on” position, which powers the electrical processing and voltage analysis equipment. Once the hook is returned to the initial position, the on-off switch moves to the “off” position. This arrangement allows the present invention to remain unpowered for any instance a wire is not being tested. The present invention detects voltage through capacitive coupling.

Abstract: A meter apparatus having three-phase judgment function includes a control unit, a multimeter measurement unit electrically connected to the control unit, a three-phase judgment unit electrically connected to the control unit, a first measurement jack electrically connected to the multimeter measurement unit and the three-phase judgment unit, a second measurement jack electrically connected to the multimeter measurement unit and the three-phase judgment unit, and a third measurement jack electrically connected to the multimeter measurement unit and the three-phase judgment unit.

Abstract: A fan testing device connects to the fan and a motherboard. The fan testing device includes a first connection module, a second connection module, a control chip, and an alarm module. The control chip is coupled to signal pins of the first and second connectors. The control chip outputs different signals to control the alarm module according to the connections of the first and second connection modules.

Abstract: A fan test device to connect a motherboard and a fan includes a power terminal, a first diode, a second diode, a control chip, a first connector, a second connector, a first electronic switch and a second electronic switch. The control chip is connected to signal pins and sensing pins of the first and second connectors. The first electronic switch is connected between the control chip and a power pin of the first connector. The second electronic switch is connected between the control chip and a power pin of the second connector. The control chip outputs different signals corresponding to the connection of the first and second connectors.