90results about "Measurement using ac-dc conversion" patented technology

The utility model provides a wireless grounding resistance precision monitoring device based on low power consumption, which comprises a power supply circuit, a wireless communication circuit, a measuring circuit and a main control circuit, and is characterized in that the power supply circuit is used for stabilizing, boosting and stabilizing the voltage of a battery and supplying power after positive and negative conversion; the wireless communication circuit is used for wirelessly sending the calculated grounding resistance value to an upper platform or a central control unit, so that a worker can monitor the equipment; the measuring circuit is used for performing amplification, filtering and alternating current-direct current conversion on the acquired grounding resistance signal and then transmitting the signal to the main control circuit to calculate a grounding resistance value; and the main control circuit is electrically connected with the wireless communication circuit and the measuring circuit and is used for controlling the wireless communication circuit to transmit and receive signals, calculating a grounding resistance value, switching working states of the wireless communication circuit and the measuring circuit and automatically awakening the wireless communication circuit and the measuring circuit. According to the wireless grounding resistance precision monitoring device provided by the invention, the wiring complexity and the power consumption are reduced, and the measurement precision is improved.

Device for measuring an alternating (AC) leakage current though a conductor, whereby the device includes: a conversion circuit including a magnetic core and a leakage current measurement circuit. The device includes a synchronous rectification circuit that includes a plurality of metal oxide semiconductor field effect transistors (MOSFETs). The conversion circuit is configured so that the conductor is arranged to pass through, or wind around the magnetic core, and the conversion circuit includes a plurality of pairs of secondary windings or a single secondary winding with a plurality of taps, whereby at least one first pair of secondary windings or at least one first pair of taps is configured to apply a voltage to the plurality of MOSFETs, and at least one second pair of secondary windings or at least one second pair of taps is connected to the synchronous rectification circuit.

The utility model discloses an expansion power supply to adapt to a multipath BDU voltage sampling circuit, comprising a flyback unit used for obtaining an alternating current, converting the alternating current into a direct current power supply and outputting the direct current power supply; the voltage adjusting unit is used for filtering and stabilizing the output direct-current voltage and then outputting a direct-current power supply; and the DCDC power supply unit is used for obtaining an output DC power supply for power supply. According to the expansion power supply, the area of a single PCB (Printed Circuit Board) and the volume of a transformer are effectively reduced by adapting to a multi-path BDU voltage sampling circuit, meanwhile, the use amount of devices is reduced, and the problem that multi-path negative sampling needs a plurality of non-common-ground power supplies is solved in a low-cost manner.

A display device according to an embodiment of the present disclosure may comprise a stand and a head supported by the stand, including a display and a battery, wherein the head is electrically connected through a pogo pin provided in a connector of the stand, wherein the head further comprises a main board configured to obtain an operating state of the head and an input voltage input to the head through the pogo pin, and determine whether an error has occurred in the pogo pin based on the operating state of the head and the input voltage.

The invention provides an air conditioner which comprises an alternating current input circuit used for outputting a power supply signal; the photoelectric coupling circuit is used for transmitting or isolating a power supply signal; the zero-cross detection circuit is used for receiving the power source signal and the preset power source signal and determining a plurality of corrected zero-cross signals according to the power source signal and the preset power source signal, errors of original zero-cross signals can be made up, the accurate zero-cross detection function of the zero-cross detection circuit is achieved, more accurate zero-cross reference is provided for the air conditioner, and the air conditioner is more accurate in zero-cross detection. It is ensured that follow-up control over loads such as a fan of the air conditioner is highly synchronous with the power cycle, and the control precision and the equipment operation stability are improved.

A signal processing system may include a sensor readout channel configured to convert an electronic signal into a digital quantity. The sensor readout channel may include a sigma-delta modulator having a modulator input and a modulator output, first system-level chopping switches located at the modulator input, an auxiliary path comprising an analog-to-digital converter (ADC) having an auxiliary path input and an auxiliary path output, the auxiliary path input configured to receive as its input signal a signal output by a memory element of the sigma-delta modulator, second system-level chopping switches located downstream of the sigma-delta modulator and the auxiliary path, and a signal combiner configured to combine a modulator output signal generated by the sigma-delta modulator with an auxiliary path output signal generated by the auxiliary path to generate a combined output signal.

The embodiment of the utility model provides an isolation detection circuit and a vehicle-mounted charger. The isolation detection circuit comprises a first voltage sampling module, a second voltage sampling module, a first isolation conversion module, a second isolation conversion module, a first signal conditioning module and a second signal conditioning module. The first sampling end of the first voltage sampling module is connected with the first end of the charging port connector, the second sampling end of the first voltage sampling module is connected with the second end of the charging port connector, and the output end of the first voltage sampling module is connected with the input end of the first isolation conversion module. The output end of the first isolation conversion module is connected with the input end of the first signal conditioning module, and the output end of the first signal conditioning module is connected with the first control module. And the voltage at the two ends of the charging port connector can be accurately and reliably detected.

A biological sensor according to one embodiment of the present technology comprises a first antenna conductor, a second antenna conductor, and a power detection unit. The second antenna conductor is different from the first antenna conductor, and is electrically coupled to a living body that is connected to a ground in the earth through direct or capacitive coupling. The power detection unit detects alternating-current power generated between the first antenna conductor and the second antenna conductor in accordance with a resistance component of the living body with respect to the ground in the earth.

Limiting circuitry is disclosed. In one example, the limiting circuitry provides limited electric current and / or limited electric voltage for electrically testing at least one device under test. The limiting circuitry comprises a plurality of DC-DC-converters being connected in parallel to each other, each being provided with an electric input DC voltage and each being configured for providing a converted electric output current to be forwarded to an assigned one of electric contacts for contacting the at least one device under test. A control mechanism is configured for controlling the DC-DC-converters for limiting the electric output current and / or an electric output voltage which relates to said electric output current.

(Figure 3) A signal processing system 100A includes a sensor readout channel that converts an electronic signal into a digital quantity. The system includes: a sigma-delta modulator 114; first sy

A system includes a rectifier configured to rectify a line power having a line energy, a buck converter configured to generate a desired voltage output based on the rectified line power, and a bypass capacitor disposed between the rectifier and the buck converter, wherein the bypass capacitor is configured to bypass a switching energy of the buck converter to attenuate a plurality of pulses of the rectified line power that are not attenuated by the buck converter, and wherein the plurality of pulses correspond to harmonics of the rectified line power.

A structural health monitoring system includes a sweep signal generator that generates alternating current signals that are simultaneously provided to a plurality of impedance measurement circuit modules. Each impedance measurement circuit module is connected to a piezoelectric sensor (PZT) that is placed on or embedded within the structure to be monitored. Each impedance measurement circuit module is used for generating two output signals. The first signal is a voltage proportional to a phase difference between an input scan signal and a PZT current signal, and the second signal is a voltage proportional to a current through the PZT. A data acquisition module digitizes these signals and generates an estimate of the real part of the (complex) impedance across the PZT at the scanning frequency. The scan signal generator is used to generate a plurality of scan signals within a scan frequency range, each scan signal corresponding to a different frequency to generate an impedance spectrum that can be used to detect structural changes such as cracks.

A hybrid current measurement system comprising: a switch coupled to a phase output and to a high-voltage bus; an amplifier coupled to the switch and configured to detect current information from the switch; a current detector coupled between the switch and the voltage bus, the current detector being configured to determine a detected current for the switch; and a current calibrator configured to calibrate the current information for the switch based on the detected current.

An electricity meter (2) for measuring one or more characteristics (4) of an electrical input (6) associated with a power source comprises a first analog-to-digital converter (ADC) (10a), a second ADC (10b) and a processing resource (12). The first ADC (10a) is configured to receive an ADC input signal (18) representing an electrical input and to generate a first ADC output data sequence (20a) representing the electrical input during a time period from the ADC input signal (18). The second ADC (10b) is configured to receive an ADC input signal (18) representative of the electrical input and to generate a second ADC output data sequence (20b) representative of the electrical input during the time period from the ADC input signal (18). The processing resource (12) is configured to determine a cross-correlation average data sequence (40) corresponding to a time period based on the first and second ADC output data sequences (20a, 20b), and to determine one or more characteristics (4) of the electrical input (6) during the time period based on the cross-correlation average data sequence (40) corresponding to the time period.

Provided are a power level acquisition circuit and apparatus, used for solving the problem in the prior art, when conducting reinforced insulation testing, of work hour wastage and safety hazards. A power acquisition circuit comprises an AC-DC conversion unit (20), an acquisition unit (21), a processing unit (22), a power supply isolation unit (23), and a communication isolation unit (24); the power supply isolation unit (23) isolates the current between the power supply side of the acquisition unit (21) and the power supply side of the processing unit (22), and the communication isolation unit (24) isolates the current when the communication end of the acquisition unit (21) and the communication end of the processing unit (22) are in communication; because of the presence of the power isolation unit (23) and the communication isolation unit (24), no large current occurs on the sampling unit (21) side, eliminating the need to disconnect the sampling terminal for enhanced insulation testing, saving work hours, and reducing safety hazards.

The present application provides an adapter and charging method, comprising: at least one filter capacitor, the capacity of which is less than a preset threshold, configured to filter rectified alternating current to generate a pulsating direct current; and a voltage transformer module configured to transform the pulsating direct current to generate a voltage and current for charging a device to be charged. The battery charging adapter provided in embodiments of the present application can reduce the size of the adapter, thereby achieving miniaturization.

Provided is a circuit capable of accurately testing the number of coil turns even with a transformer having a high turns ratio. A transformer turns number testing circuit is able to connect primary-side coils and secondary-side coils of a reference transformer and a to-be-tested transformer in phase and in series, and includes: a reference-side resistance element included in a reference-side loop circuit formed between both ends of the secondary-side coil of the reference transformer; a to-be-tested-side resistance element included in a to-be-tested-side loop circuit formed between both ends of the secondary-side coil of the to-be-tested transformer; and a voltage detector provided in a common line of the reference-side loop circuit and the to-be-tested-side loop circuit, the common line connecting a midpoint between the secondary-side coils of the reference transformer and the to-be-tested transformer and a midpoint between the reference-side resistance element and the to-be-tested-side resistance element.

Circuit arrangement for measuring conductor current, wherein a current transformer generates an input voltage from the current, and a first output of a diode bridge circuit is located at the connection of two identical first electrodes of diodes, where a measuring resistor is inserted between two identical second electrodes of the diodes of the diode bridge circuit, a second output of the diode bridge circuit is located at the connection one diode to the second electrodes and the measuring resistor, and an extended bridge node is located at the connection of the other diodes, the second electrodes and measuring resistor, and diodes are formed by source-drain diodes of a first and second field-effect transistors, and a control apparatus actuates gates of the first and second field-effect transistors via a control voltage, and a measuring apparatus measures a measuring voltage at the measuring resistor that is proportional to the current.

The invention provides a converter transformer equipment grounding current monitoring device which comprises a current transformer, a cross coupling type rectifier bridge, a DC-DC module, a wireless sensing module and a differential amplifier. It is ensured that appropriate and stable direct-current voltage output can be provided for the sensor module when the current is too small or too large, the problem of insufficient power or circuit damage is effectively avoided, in the aspect of a rectifying circuit, the energy conversion efficiency under the low-amplitude current condition is remarkably improved through a high-efficiency rectifying technology, and the energy conversion efficiency is improved. And the high-efficiency operation of the sensor module can be maintained even in a micro-current environment. Meanwhile, by optimizing a starting mechanism, quick response and starting of small current signals are achieved, the response time of the monitoring device is greatly shortened, and the accuracy and timeliness of fault early warning are improved.

The present application provides a current detection circuit, comprising a current transformer, a magnetic reset circuit, a chip select circuit, a sampling circuit and a clamp circuit. The primary winding of the current transformer receives the current to be detected and generates a sampling current in the secondary winding. The magnetic reset circuit is used to reset the current transformer. The chip select circuit is electrically connected to the magnetic reset circuit and can be switched between a first mode and a second mode. The first mode is used to detect a current to be detected having a first direction, and the second mode is used to detect a current to be detected having a second direction opposite to the first direction. The sampling circuit is electrically connected to the chip select circuit to sample the sampling current and output a sampling signal to a controller. The clamp circuit is electrically connected between the sampling circuit and the controller and provides a reference potential. The present application also provides a converter having the current detection circuit.

A control system includes a power converter being a step-down voltage converter and including a power switch. The power converter is operable to generate an adjustable output voltage and includes a sensor circuit configured to measure at least one of a voltage and an electric current of the heater. The control system includes a controller connected to the power converter and the sensor circuit. The controller is configured to determine an input parameter based on the at least one of the voltage and the electric current. The input parameter is indicative of a temperature of the heater. The controller is configured to set the output voltage applied for the heater based on the input parameter and a desired setpoint. The desired setpoint is based on an operational state of the heater. The controller is configured to operate the power switch of the power converter to generate the output voltage.

Provided is a measured waveform phase control device and method of a merging unit (MU) which obtains an accurate value at a sampling command time, corrects characteristics of a change in temperature of an oscillator element, and also corrects delay characteristics of an analog sensing element at the sampling command time. A measured waveform phase control device of an MU of the present invention includes a temperature sensor which provides ambient temperature information, an oscillator element which provides an oscillation signal, an analog-digital converter (ADC) which samples an analog current sensing signal or voltage sensing signal as a digital signal, and a sampling clock providing part which provides a sampling clock to the ADC on the basis of the ambient temperature information and the oscillation signal under control of a sampling request part.

The present invention relates to a system including a multifunctional DC power quality (PQ) meter, and an operation method thereof, the system comprising: the PQ meter; and a manager terminal, in particular, wherein the PQ meter includes: a first signal generation circuit that includes a current transformer and a voltage transformer, which are connected to both ends of an alternate current (AC) wire disposed at one end of AC / DC power converter, and applies first signals in connection with AC current and AC voltage, respectively, from the current transformer and voltage transformer; a second signal generation circuit that is connected to a DC wire disposed at the other end of the AC / DC power converter and applies second signals in connection with DC voltage and DC current, respectively, from the DC wire; a communication circuit; and a control circuit that generates PQ data based on applied signal, when at least one among the first and second signals is applied, and then transports the PQ data to the manager terminal at a constant cycle.

An electricity meter (2) for measuring one or more properties (4) of an electrical input (6) associated with a power supply, comprises a first analogue-to-digital converter (ADC) (10a), a second ADC (10b) and a processing resource (12). The first ADC (10a) is configured to receive an ADC input signal (18) which is representative of the electrical input and to generate, from the ADC input signal (18), a first ADC output data sequence (20a) which is representative of the electrical input during a time period. The second ADC (10b) is configured to receive the ADC input signal (18) which is representative of the electrical input and to generate, from the ADC input signal (18), a second ADC output data sequence (20b) which is representative of the electrical input during the time period. The processing resource (12) is configured to determine a cross-correlated average data sequence (40) corresponding to the time period based on the first and second ADC output data sequences (20a, 20b) and to determine the one or more properties (4) of the electrical input (6) during the time period based on the cross-correlated average data sequence (40) corresponding to the time period.

Disclosed herein is a contactless DC electric-field sensor having improved sensitivity. The contactless DC electric-field sensor has a circuit composed of a variable capacitor and an RF generator and improves sensitivity through resonance of the circuit by connecting an inductor to the sensor.

The invention provides a passive direct-current voltage sensor which is powered by a tested direct-current high voltage and comprises a voltage division circuit, an input end of which is coupled with the tested direct-current high voltage and is used for converting the direct-current high voltage into a low-voltage signal in proportion; the equivalent resistance value of the non-linear correction circuit is reduced along with the reduction of the voltage at the two ends, and the non-linear correction circuit is used for compensating the overall equivalent input impedance of the voltage division circuit and the modulation circuit during small voltage input; the load compensation circuit is used for compensating the subsequent modulation circuit when the load changes and stabilizing the output voltage; the modulation circuit is used for linearly converting a signal of the load compensation circuit into an alternating current signal and is internally provided with a high-frequency transformer for realizing electrical isolation; the demodulation filter circuit is used for rectifying and filtering the alternating-current signal into a direct-current low-voltage output signal which is in fixed proportion to the detected direct-current high voltage; and heat-conducting insulating glue is filled between the radiator and the divider resistor and is used for enhancing heat dissipation and insulation. The technical problems that accurate monitoring of weak voltage changes is not enough, and the space occupation amount of the voltage division circuit is large are solved.

Circuit arrangement for current measurement in a conductor (L) carrying a current (I), wherein a current transformer (CT) is configured to generate an input voltage (U) from the current (I) in the conductor (L), which is supplied to the input (B1, B2) of a diode bridge circuit (B), and a first output (B3) of the diode bridge circuit (B) is located at the junction of two identical first electrodes (E1, E2) of the diodes (D1, D2) of the diode bridge circuit (B), wherein a measuring resistor (R) for current measurement is inserted between the two identical second electrodes (E3, E4) of the diodes (D3, D4) of the diode bridge circuit (B), a second output (B4) of the diode bridge circuit (B) is located at the junction of one of the diodes (D3, D4) with the second electrodes (E3, E4) and the measuring resistor (R), and a extended bridge junction (B5) at the connection of the other diodes (D3, D4) with the second electrodes (E3,E4) and the measuring resistor (R), and that diode (D4) of the diode bridge circuit (B), which is located at the second output (B4), is formed by the source-drain diode of a first self-blocking field-effect transistor (T1), and that diode (D3) of the diode bridge circuit (B), which is located at the extended bridge node (B5), is formed by the source-drain diode of a second self-blocking field-effect transistor (T2), and a control device (CU) is provided to drive the gate (G1) of the first field-effect transistor (T1) and the gate (G2) of the second field-effect transistor (T2) by means of the same control voltage, and a measuring device (MU) is provided to measure a measuring voltage across the measuring resistor (R), which is proportional to the current (I) in the conductor (L).

A cordless vacuum cleaner includes a cleaner main body and a station. The cleaner main body includes a battery and a first processor controlling performing a cleaning function using power of the battery. The station includes a power conversion device to generate a voltage to charge the battery of the cleaner main body, a second charge terminal to charge the battery of the cleaner main body with the voltage generated by the power conversion device, a temperature sensor installed within a distance from the second charge terminal and to detect a temperature of the second charge terminal, a divider resistor to provide a voltage by dividing of an input voltage with the temperature sensor, and a second processor controlling performing an overheating prevention operation based on a voltage level of the voltage provided by the divider resistor and the temperature sensor being greater than a threshold voltage level.