899 results about "Low voltage circuits" patented technology

In low-voltage circuits, there is often insufficient voltage to use a current source to bias a transconductance amplifier stage. This is particularly true in mixers where a switching circuit must be stacked on top of the transconductance input stage. One way around this problem is to get "double-duty" out of the input differential pair, using it both for gain stage and for DC bias. This is done by AC coupling in a high-frequency input signal, while using a low-frequency, DC-coupled circuit to establish the proper bias level. One common technique is to use a simple current mirror scheme to establish the DC level. Proper biasing using this technique requires good matching of resistance. In some implementations of transconductance amplifiers, particularly those that use inductors as degeneration elements, series resistance of the inductor and interconnect resistance can cause significant errors in the bias current. This invention addresses that problem by using an operational amplifier with a current-sensing resistor and a low-frequency feedback loop to compensate automatically for any resistance errors. The operational amplifier drives the feedback voltage (generated in accordance with the sensed voltage at the current-sensing resistor and applied to one input of the operational amplifier) towards a reference voltage that is applied to the other input of the operational amplifier to bias the transistor(s) in the transconductance amplifier for desired operating conditions.

The vehicular insulation resistance detection apparatus includes a cyclic signal generating unit that generates a cyclic signal, a first resistor that has one end to which the cyclic signal is applied, a first capacitor that has one end connected to the other end of the first resistor and the other end connected to a high-voltage circuit, a second capacitor that has one end connected to the other end of the first resistor, a second resistor that has one end connected to the other end of the second capacitor and the other end connected to a low-voltage ground that is a circuit ground of a low-voltage circuit, a series circuit that includes a diode and a third resistor connected in series, and is connected in parallel with the second capacitor, this diode having a forward direction coincident with a direction from the other end of the second capacitor to the one end of the second capacitor, a voltage detection unit that detects a voltage between the low-voltage ground and the other end of the second capacitor as a detection signal, and an insulation resistance detection unit that detects a resistance value of an insulation resistance based on an amplitude of the detection signal.

A semiconductor device including a substrate, a high voltage device, a medium voltage device and a low voltage device is provided. The substrate includes a high voltage circuit area, a medium voltage circuit area and a low voltage circuit area. The high voltage device, the medium voltage device and the low voltage device are respectively disposed in the high voltage circuit area, the medium voltage circuit area and the low voltage circuit area. The medium voltage device and the high voltage device have the same structure while the medium voltage device and the low voltage device have different structures. Further, the high voltage device, the medium voltage device and the low voltage device respectively include a first gate dielectric layer, a second gate dielectric layer and a third gate dielectric layer, and the thickness of the second gate dielectric layer is smaller than that of the first gate dielectric layer.

The invention provides an on-line three-phase load unbalance processing method suitable for a low-voltage distribution network. The on-line three-phase load unbalance processing method comprises the following steps of: monitoring three-phase load by three-phase load monitoring units on the low voltage side of a distribution transformer, and transmitting monitoring data to three-phase load unbalance monitoring units of the distribution transformer; judging whether the three-phase load unbalance exceeds a standard value or not by the three-phase load unbalance monitoring units of the distribution transformer; if the three-phase load unbalance exceeds the standard value, transmitting signals to an on-line load phase modulation control unit by a communication unit; judging whether the three-phase load unbalance of the distribution transformer is caused by the three-phase load unbalance of a main low-voltage circuit or not by the on-line load phase modulation control unit; and if so, setting an on-line load phase modulation strategy according to the monitoring data of the load monitoring units of branches of three phases of the main low-voltage circuit, sending a control command to an on-line load phase modulation switch combination unit by an on-line load phase modulation judging and controlling unit, and switching the load phases of the branches of users so as to realize the on-line three-phase load unbalance processing.

The invention relates to a low-voltage electric wire carrier communication test method and a testing system thereof. The testing method comprises the following testing methods: I, a carrier transmitting PWL online testing method; II, a carrier receiving sensitivity online testing method; III, a carrier communication anti-interference online testing method; IV, a low-voltage circuit impedance change online testing method. The testing system comprises a carrier transmitting device, a program control attenuating device, a tested carrier receiving device, a manual power network, a frequency spectrograph receiver, a computer, a frequency spectrograph, a noise simulator, an impedance simulator and a purifying power. The invention has the advantages of adopting a manual power network parameter model regulated in GB/T 6113 F2, thus having a high standardization degree and comparable testing data; avoiding the testing problems brought by adopting different carrier communication schemes; realizing the online sensitivity testing; carrying out the test at any time and being not affected by the external environment factors like the weather; besides, the invention can simulate the impedance change environment of a real circuit, thus leading the analyzing of the carrier communication on the impedance change of the circuit to be feasible.

Maintenance trip functions override the normal or specified trip functions of a low voltage circuit breaker to reduce pickup currents and/or time delays to effect faster trips, which reduces arc energy produced by faults during maintenance or testing on a live circuit breaker.

An electrical power supply device for electric propulsion aircraft includes first and second electric motors configured to ensure the propulsion of the aircraft. First and second high-voltage electrical circuits are connected respectively to the two electric motors. A low-voltage electrical circuit is connected to at least one control and/or command facility of the aircraft. First and second pack of batteries are connected respectively to the two high-voltage electrical circuits. First and second battery management systems are connected to the low voltage circuit. Two battery management systems are linked respectively to the two packs of batteries. An electrical converter is connected to the first high-voltage electrical circuit and to the low-voltage electrical circuit.

Provided is a low-cost compressor having excellent operation stability which enables the improvement of the stability of a control circuit by shielding electromagnetic noise and the effective prevention of the vibration of a control substrate while the design flexibility is maintained at the same high level as that of conventional ones. An inverter-integrated electric compressor in which a motor is incorporated and a high-voltage circuit for motor drive including an inverter and a control substrate provided with a low-voltage circuit for control are provided in a compressor housing is characterized in that a shield plate made of a material capable of shielding an electromagnetic noise emitted from the high-voltage circuit for motor drive toward the low-voltage circuit for control is interposed between the high-voltage circuit for motor drive and the control substrate, and the shield plate and the control substrate are fixed to each other and both are fixed at a predetermined position in the compressor housing.

The invention relates to a breaking test device and test method for a high-voltage direct current breaker. A reactor L of the device is connected in series with the high-voltage direct current breaker and then separately connected in parallel with a high-voltage circuit and a low-voltage circuit; a bypass switch is connected in parallel to two ends of the high-voltage direct current breaker; and a protection thyristor is connected in parallel to two ends of a full-bridge module in a mechanical switch-full-bridge module branch. In the test method, rated current from a low-voltage high-current source is injected to the breaker via a thyristor isolating valve; a capacitor is charged by a high-voltage low-current source, initial test voltage is established, the high-voltage circuit is discontinuously triggered by spark, the test current is adjusted by the reactor and then injected into the breaker, the thyristor isolating valve is switched off, breaking is accomplished when the expected breaking current or the maximum breaking time arrives, and the breaker tolerates transient recovery overvoltage and residual voltage of the capacitor in the high-voltage circuit. The device and the method can reproduce current, voltage and thermal stress of the high-voltage direct current breaker in practical operation, are high in test equivalence, and have the capability of reliably detecting the breaking performance of the breaker.

The invention discloses a battery pack and a vehicle. The battery pack comprises a shell, a battery module, a connector and a high-low voltage integrated circuit board, wherein the end part of the battery module is provided with a floating pair plug-in, the floating pair plug-in comprises a base and a floating terminal, the floating terminal is arranged in the base, the floating terminal comprisesa high-voltage plug bush and a low-voltage plug bush, the connector comprises a base board and a fixed terminal, the fixed terminal is fixed on the base board and the upper end and the lower end of the fixed terminal are respectively exposed at the upper surface and the lower surface of the base board, the fixed terminal comprises a high-voltage terminal and a low-voltage terminal, the circuit board comprises an insulated board, a high-voltage circuit board and a low-voltage circuit board, and the high-voltage circuit board and the low-voltage circuit board are arranged in the insulated boardand is electrically insulated through the insulated board. In the battery pack, the connector and the floating pair plug-in are connected in plug fit so as to combine the battery module and the circuit board tightly and arrange the battery module and the circuit board in order in the battery pack.

A comprehensive evaluation method for the line loss level of a low-voltage transformer area comprises the steps as follows: equivalent resistance of distribution lines in the low-voltage transformer area is calculated respectively; the line loss rate and head end average load current of a low-voltage circuit are measured; a load curve characteristic coefficient and a three-phase unbalanced line loss correction coefficient are calculated respectively; the theoretic line loss rate in the low-voltage transformer area is calculated, and the measured line loss rate and the theoretic line loss rate are compared, so that the management line loss level in the low-voltage transformer area is judged; and the like, wherein the head end average load current, the load curve characteristic coefficient, the three-phase unbalanced line loss correction coefficient and the like are calculated along with a calculation method of the theoretic line loss of the to-be-calculated low-voltage transformer area after a simultaneous equation set is established. According to the method, the parameters and a management line loss evaluation threshold can be accurately calculated, and comprehensive evaluation of the line loss level of the low-voltage transformer area can be accurately completed further; and particularly, when electricity stealing and leakage conditions occur, the method can accurately judge the line loss level, and misjudgments are avoided.

An energizer for an electric fence having a wire with feed and return terminals. The energizer includes a high voltage pulse generator for generating high voltage pulses at the feed terminal and a low voltage circuit for providing a low voltage signal at the feed terminal and for monitoring any changes in the low voltage signal at the return terminal to determine if the wire of the fence is touched, or if a short circuit or open circuit exists. An impedance decouples the high voltage pulses from the low voltage circuitry. The low voltage circuit makes measurements of electrical characteristics of the wire between the high voltage pulses. A low voltage intrusion detection system and related methods are also disclosed.

Disclosed is a power supply with a control circuit comprising a capacitively coupled bridge circuit (10) for using a low-voltage circuit to operate a high-voltage circuit. The invention maintains isolation between the high-and low voltage sections by using a capacitor (20).

The present invention includes processes and packaging for high voltage integrated circuits (ICs), high voltage electronic devices and high voltage electronic circuits which operate over a wide range of voltages, e.g., from tens of volts to tens of thousands of volts. The inventive processes and packaging are particularly suitable for integrating low or lower voltage circuits or transistors to form high voltage ICs, high voltage electronic devices and high voltage electronic circuits. The inventive processes and packaging are also particularly suitable for isolating high voltage electronics to achieve high breakdown voltages and for supporting high voltage operation. The inventive processes may be used with any suitable semiconductor materials using conventional semiconductor fabrication and related facilities.

A system, apparatus, and method for allowing LED operation in circuits operating with power supply levels that are below the forward voltage limits of the LED. A first level of a modulated voltage signal is applied to charge a voltage increasing component in a first phase of operation. A second level of the modulated voltage signal is then summed with the voltage stored across the voltage increasing component to provide adequate forward potential across Light Emitting Diode (LED) for illumination. The second level of modulated voltage is also used to provide a source of constant forward current to be conducted by LED when in its luminescent state.

The invention discloses an anti-bouncer for a circuit breaker, belonging to the field of low-voltage circuit breakers. The anti-bouncer comprises a main shaft, a driving component, a link system, a backstop, a hook rod, a shaft pin, a side plate and a return spring, wherein the side plate is fixed on a shell frame of the whole circuit breaker and plays the effects of supporting and spacing other components; the main shaft passes through a spacing hole in the side plate and is rotatable; the driving component is fixed on the main shaft; the shaft pin is fixed on the side plate; and the hook rod passes through the shaft pin and can rotate around the shaft pin. The invention is characterized in that when the circuit breaker trips, an inclined plane on the driving component collides with the hook rod, so that the hook rod obtains initial speed for clockwise rotation, and the hook rod continues to rotate under the inertia force and enters a groove on the driving component, thereby hooking the driving component and achieving the anti-bounce effect. The device has simple structure, reliable performance and long mechanical service life, and can effectively prevent the bounce of contacts to improve the performance of the circuit breaker.

The invention discloses a high-voltage start-up circuit which comprises a current source, a control switch and a capacitor, wherein the current source for inputting high-voltage power supply is connected with the capacitor through the control switch to form a charging loop; one end of the capacitor is an output end, and the other end is grounded; and an enabling end of the control switch is connected with a logic control output end of a low-voltage circuit. The start-up circuit is characterized in that a negative feedback circuit is arranged between the output end of the capacitor and the current source, and the negative feedback circuit consists of a detection circuit and a feedback control circuit; the detection circuit is connected between the current source and the output end of the capacitor in series and used for detecting the magnitude of output current; and the feedback control circuit is used for receiving the output of the detection circuit and feedback controlling the current source. In the invention, the current source is feedback controlled according to the magnitude of the output current through arranging the negative feedback circuit, the current is not sensitive to high voltage, and the current linearity is good.

The present invention provides a nonvolatile semiconductor memory that allows simultaneous implementation of high performance transistors in a low-voltage circuit region and transistors with high withstand voltages in a high-voltage circuit region. The nonvolatile semiconductor memory includes a cell array region that comprises aligned memory cell transistors, each including a control gate electrode, which includes a metal silicide film, an inter-gate insulating film below the control gate electrode, a floating gate electrode below the inter-gate insulating film, and a tunnel insulating film under the floating gate electrode; a high-voltage circuit region arranged in a periphery of the cell array region and including a high voltage transistor, which includes a first gate insulating film thicker than the tunnel insulating film; and a low-voltage circuit region that is arranged in a different position than the high-voltage circuit region arranged in the periphery of the cell array region and that includes a low-voltage transistor, which includes a gate electrode and a second gate insulating film thinner than the first gate insulating film below the gate electrode.

The invention relates to a main-contact electrical-contact state on-line detector for a low-voltage circuit breaker, which comprises a static-contact side voltage detection circuit, a static-contact side power circuit, a traveling-contact side voltage detection circuit and a traveling-contact side power circuit, wherein the static-contact side voltage detection circuit and the static-contact sidepower circuit are arranged at the end of an electric line power source of a low-voltage circuit breaker; the traveling-contact side voltage detection circuit and the traveling-contact side power circuit are arranged at the end of an electric line load of the low-voltage circuit breaker; the static-contact side voltage detection circuit and the traveling-contact side voltage detection circuit transmit data through optical fibers; the static-contact side power circuit independently supplies power to the static-contact side voltage detection circuit, and the traveling-contact side power circuit independently supplies power to the traveling-contact side voltage detection circuit; and the traveling-contact side voltage detection circuit transmits the collected electric line phase voltage data to the static-contact side voltage detection circuit through optical fibers. The detector has the advantage of convenient and safe operation, accurately measures the voltage difference between the static contact and the traveling contact of the low-voltage circuit breaker on line in real time, can judge the electric contact state of the main contact of the low-voltage circuit breaker, and ensure the electrical insulation of the static contact side and the traveling contact side when the low-voltage circuit breaker is in the off state.