5 results about "Precision rectifier" patented technology

The present invention discloses a five-phase permanent magnet synchronous motor overcurrent control method that combines software and hardware, and belongs to the technical field of power generation, power transformation or power distribution. The current information collected by each phase current sensor is converted into a dual-pulse DC signal through a precision rectifier circuit, and then the dual-pulse DC signal and the reference signal are compared to generate an independent overcurrent pulse signal. The five-phase independent overcurrent pulse signals are connected at the output end of the comparator in a "line-AND" manner to achieve pulse signal fusion and immediately block the IGBT drive signal. The corresponding I / O port of the microcontroller is configured as an interrupt input to quickly respond to the overcurrent pulse line-AND signal, and then the IGBT drive signal is blocked in a pulse-by-pulse manner and reopened after one switching cycle. After the number of overcurrent pulses reaches a preset value, the driver is completely turned off and marked as a continuous overcurrent event. The present invention is simple and reliable and can effectively avoid false protection actions.

This utility model discloses a voltage detection device for power transmission and transformation equipment, including a voltage detector. The voltage detector includes a voltage detection circuit and an alarm circuit. The voltage detection circuit includes a voltage divider and limiter circuit, a voltage follower circuit, a second-order low-pass filter circuit, a dual-power precision rectifier circuit, a microcontroller, and an alarm circuit. The voltage divider and limiter circuit is used to induce voltage. The voltage follower circuit utilizes the characteristics of high input impedance and low output impedance for impedance matching. The second-order low-pass filter circuit filters out high-frequency noise signals. The induced voltage from the dual-power precision rectifier circuit is transmitted to the microcontroller. When the induced voltage exceeds a set value, the microcontroller sends a signal to the alarm circuit. This voltage detection device for power transmission and transformation equipment can sensitively react to weak induced voltage inputs and issue warning signals, which can prevent electric shock accidents during high-voltage maintenance. It is also easy to install on grounding rods and grounding wires, and can also be connected to an extension pole for independent voltage detection.

The invention discloses a knocking sensor circuit and a household appliance. The knocking sensor circuit comprises a vibration mechanism, a precision rectification circuit and a controller. The vibration mechanism is used for outputting an AC voltage signal after receiving mechanical vibration. The precise rectification circuit is connected with the vibration mechanism and is used for converting the alternating-current voltage signal into a direct-current voltage signal; and the controller is connected with the precise rectifying circuit and is used for generating a pulse waveform signal based on the direct-current voltage signal and judging whether effective knocking occurs or not based on the pulse waveform signal. Through the above mode, the knocking sensor circuit rectifies an original AC voltage signal into a DC voltage signal suitable for being processed by a controller through additionally arranging the precision rectification circuit, thereby reducing the cost of the controller, and reducing the software development difficulty.

Control circuit (30) for at least two contactors, comprising - a first and a second terminal (11, 12) via which the control circuit (30) can be connected to the poles of an energy storage device, - at least one first output (15) and at least two second outputs (16), via which the control circuit (30) can be connected to the terminals of at least two control coils for at least two contactors, wherein the at least two second outputs (16) are each connected to the second terminal (12) via an electrical connection (8), - a holding voltage unit (10) which has an output (6) and an input (9) for receiving a control signal and which is connected via its output (6) to the at least one first output (15) and is designed to provide a holding voltage for setting a holding current for the control coils at its output (6), characterized in that the control circuit (30) has a control circuit (20) which is connected to the electrical connections (8) and the input (9) of the holding voltage unit (10) and is designed to generate a control signal dependent on the currents flowing in the electrical connections (8) and to transmit it to the holding voltage unit (10), wherein the control circuit (20) comprises a minimum current selection circuit (5) which has an output and is designed to measure the actual values ​​of the currents flowing through the electrical connections (8) and to select the minimum of the measured actual values ​​of the currents I min about their outcome, wherein the minimum current selection circuit (5) has a resistor (4) and, for each electrical connection (8), a precision rectifier (7) each having two inputs and one output, wherein each electrical connection (8) is connected to a respective input of a precision rectifier (7), while the respective other input of the respective precision rectifier (7) is fed back to the output of the respective precision rectifier (7), wherein the outputs of all precision rectifiers (7) are connected to a terminal of the resistor (4).

A system includes first precision rectifier operatively connected to receive high and low signals of a sine coil of a resolver and to output a first signaled condition and an exciter coil of the resolver. A second precision rectifier is operatively connected to receive high and low signals of a cosine coil of the resolver and to output a second signaled condition. A quadrant detection circuit operatively connected to receive high and low signals of the exciter coil of the resolver, high and low signals from the sine coil, and high and low signals from the cosine coil. The quadrant detection circuit outputs a signal indicative of quadrant position of the resolver.