16 results about "Bipolar voltage" patented technology

An ultrasonic imaging system has a bias-switchable, ultrasonic transducer array and a bipolar voltage source. The array has a dielectric layer having a top surface and a bottom surface; top and bottom electrode strips in electrical contact with the top and bottom surface of the dielectric layer, the bottom electrode strips being oriented at a non-zero angle relative to the top electrode strips. There is an acoustic matching layer or multiplicity of matching layers on the front-side of the array and a leakage-current mitigation layer. The bipolar voltage source is connected to each of the top and bottom electrode strips to induce a polarization in the dielectric layer, the bipolar voltage source being capable of switching between a high voltage state and a low voltage state. A controller controls the bipolar voltage source, and pulsing to and receiving signals from the top and bottom electrode strips.

The utility model relates to the technical field of power supply circuits, in particular to a bipolar output circuit for a photoresist constant-temperature power supply, which comprises a bipolar inverter circuit, a driving control circuit and an auxiliary power supply circuit. The isolation driving circuit uses a simple optical coupler device, a special digital driver or a high-speed driving optical coupler is not needed, an upper tube driving auxiliary power supply directly couples to generate two paths of driving power supplies through a mode of adding an auxiliary winding on an inductor of a conventional PWM converter, an additional independent auxiliary power supply is not needed, a bipolar voltage output function is realized, and the voltage output is realized. The circuit has the advantages of no physical contact, long service life, simple circuit and low cost.

The invention discloses a bipolar voltage-time converter based on phase inverter threshold detection. The bipolar voltage-time converter is characterized in that a differential sampling circuit is connected with a sign bit comparator and a bipolar voltage-time conversion circuit; the sign bit comparator is used for receiving the differential sampling voltage output by the differential sampling circuit and judging the polarity of an input differential analog signal, and is connected with the bipolar voltage-time conversion circuit to output a sign bit signal and a polarity control signal; the bipolar voltage-time conversion circuit is used for charging or discharging the differential sampling voltage under the control of the polarity control signal to generate two paths of voltage ramp signals with opposite polarities, and is connected with the common-mode feedback circuit and the inverter threshold detection circuit; the common-mode feedback circuit is used for detecting a common-mode level of the differential sampling voltage or two paths of voltage ramp signals; the threshold voltage of the inverter threshold detection circuit is configured to be a predetermined common-mode level, and is used for detecting a crossover event of the two voltage ramp signals at the predetermined common-mode level and outputting a threshold detection signal.

This invention discloses a bidirectional bipolar input / output DC-DC converter topology, which is an asymmetric structure centered on a high-frequency transformer T1 with a center tap. It includes a first circuit unit, the high-frequency transformer T1, and a second circuit unit connected in sequence. The first circuit unit employs a half-bridge or full-bridge structure, and the second circuit unit also employs a half-bridge or full-bridge structure. At least one of the first and second circuit units uses a bidirectional switching structure with two switches connected in reverse series, enabling mutual conversion between the bipolar voltages of the first and second circuit units, thus multiplying the voltage variation range on the output side. This invention improves upon traditional bipolar DC-DC converters, achieving stable and adjustable voltage gain by changing the switching frequency while realizing high-frequency, high-efficiency bipolar DC-DC conversion, significantly improving the converter's wide-range voltage supply capability.

The invention provides an overvoltage protection device and an overvoltage protection method, which can utilize a processor to detect the stoping voltage of a voltage acquisition circuit, and if the stoping voltage exceeds a first voltage limit range, a first cut-off instruction is sent to a first overvoltage protection circuit to cut off the transmission of bipolar voltage by the first overvoltage protection circuit; moreover, in order to improve the accuracy of the overvoltage protection of the bipolar voltage, the bipolar voltage transmitted by the first overvoltage protection circuit is detected by using the second overvoltage protection circuit, and if the bipolar voltage exceeds a second voltage limiting range, the transmission of the bipolar voltage by the second overvoltage protection circuit is cut off. Therefore, the overlarge bipolar voltage is prevented from being transmitted to the load through the voltage acquisition circuit, and the load can be ensured to always work in a normal voltage range through dual overvoltage protection of the first overvoltage protection circuit and the second overvoltage protection circuit.

The invention relates to the technical field of electronic measurement, in particular to a low-common-mode bipolar edge-control constant-current excitation low-value resistance testing method. The low-common-mode bipolar edge-control constant-current excitation low-value resistor testing device comprises a bipolar edge-control voltage module, a constant-current control module, a low-common-mode excitation module, a tested resistor and a sampling end module, the method comprises the steps that S1, a DAC voltage source of a bipolar edge control voltage module provides a bipolar voltage source Vdac with an edge control function; s2, the output voltage Vref of the bipolar edge control voltage module is connected with a constant current control module; s3, the excitation output low end of the constant current control module is connected with a low common mode excitation module; s4, the excitation output low end and the excitation output high end of the low common mode excitation module are connected with the tested resistor through a test cable; and S5, the induction high end and the induction low end of the test cable are connected with a sampling end module. According to the invention, the edge control technology and the constant current excitation technology are combined, and low-common-mode and high-precision low-value resistance measurement is realized.

The embodiment of the invention discloses a medium-voltage power supply system and a solid-state transformer system, and belongs to the technical field of power conversion. The medium-voltage power supply system comprises at least one set of solid-state transformer system; the solid-state transformer system comprises a plurality of bridge arm modules, each bridge arm module comprises a plurality of solid-state transformer modules, and the solid-state transformer modules output unipolar voltage; the input ends of the plurality of bridge arm modules are connected with a three-phase power grid by adopting a preset three-phase topological connection mode; wherein the voltage value of the three-phase power grid is greater than or equal to a preset voltage threshold value; in the at least one solid-state transformer system, the output end anode of at least one bridge arm module is connected with the DC bus anode, the output end cathode is connected with the DC bus midpoint, the output end anode of at least one bridge arm module is connected with the DC bus midpoint, and the output end cathode is connected with the DC bus cathode; bipolar voltage can be output on a direct current bus, bipolar output is achieved, and the requirement for bipolar output of part of loads is met.

A polarity-adjustable high-voltage pulse generator includes: a control signal generation module, an opto-isolation drive module, a solid-state switch drive module, a Marx circuit low-voltage generation module, a relay polarity switching module, a pulse transformer boost unit module, and a load. This invention proposes a polarity-adjustable high-voltage pulse source based on a Marx-type circuit combined with a pulse transformer. Only a small number of Marx circuit stages are needed as the front-end low-voltage output unit, and high-voltage output is achieved by using a pulse transformer to boost the voltage. Simultaneously, the primary winding of the low-voltage output unit is connected to the Marx circuit using a high-frequency relay. By controlling the relay switching, the polarity of the high-voltage pulse generator is adjustable. The high-voltage pulse generator proposed in this invention can achieve high-amplitude single positive polarity, single negative polarity, and bipolar voltage outputs.

An isolated bipolar output self-voltage balancing DC-DC converter, the converter comprising a forward converter, a bipolar voltage balancing unit; the forward converter comprises a DC input source u in , a power switch S1, a reset inductor L p1 , a transformer T, a reset diode D p1 , a rectifier diode D1, a freewheeling diode D2, an inductor L 1, an output capacitor C 1; the bipolar voltage balancing unit comprises a rectifier diode D3, a freewheeling diode D4, an inductor L 2, an inductor L 3, an output capacitor C 2, a voltage balancing capacitor C p The application can effectively reduce the voltage imbalance problem caused by cross regulation ratio of the traditional forward converter in bipolar output, reduce voltage deviation, and the circuit control is simple, the automatic voltage balancing of the bipolar output is realized through the bipolar voltage balancing unit, without complex sampling and control algorithm, the control system design and implementation difficulty is low, and the application is suitable for the occasions requiring bipolar voltage power supply.

This invention provides a high-voltage unipolar and bipolar voltage-current modulation communication detonator electronic circuit, belonging to the field of electronic detonators. It solves the problem that existing low-voltage powered electronic detonator chips cannot drive high-voltage plasma exciters. The circuit includes a high-voltage unipolar voltage regulator circuit, a unipolar / bipolar voltage modulation communication detonator electronic chip driver circuit, and a high-voltage plasma exciter trigger circuit. The input terminals of the high-voltage unipolar voltage regulator circuit are connected to the detonator pin terminals LINE-A and LINE-B, respectively. The output terminal of the high-voltage unipolar voltage regulator circuit outputs high-voltage electricity to the high-voltage plasma exciter trigger circuit. The other output terminal of the high-voltage bridge is connected to the unipolar voltage modulation communication detonator electronic chip driver circuit. The unipolar / bipolar voltage modulation communication detonator electronic chip driver circuit outputs a driving signal to the high-voltage plasma exciter trigger circuit. This invention is applied to high-voltage plasma exciter electronic detonators without detonating explosives.

The application discloses a new energy island power grid transmission system through flexible DC overhead lines, adopts a bipolar DC structure, improves the flexibility and reliability of system operation, and energy storage devices are used for inhibiting intermittent characteristics and fluctuation characteristics of new energy; the coordinated cooperation of an AC energy consumption device at a sending end, a sending end flexible DC converter and new energy units realizes the consumption of surplus power at the sending end; the same outer loop controller is applied to a double closed loop control system of the sending end bipolar, so that the fighting phenomenon possibly occurring in the voltage frequency control of the sending end bipolar can be avoided; and the receiving end flexible DC converter station adopts a fixed DC voltage control strategy and a fixed active power control strategy, and when a DC line is faulty, the faulty current is controlled to be cut off, so that the DC fault self-clearing of the new energy island power grid transmission system through the flexible DC overhead lines is realized, and the technical problems of the coordinated control difficulty of the new energy and the flexible DC, the influence of power surplus on the stable operation of the system and the incapability of self-clearing of the DC side fault are solved.

A bipolar output cross regulation improvement circuit, the circuit comprises a bipolar output double-tube flyback converter, a cross regulation capacitor C p The bipolar output double-tube flyback converter comprises a DC input source u in , a power switch S1, a power switch S2, an excitation inductor L m , a transformer T, a clamping diode D 1p , a clamping diode D 2p , a diode D1, a diode D2, an output capacitor C 1, an output capacitor C 2; compared with the traditional bipolar output double-tube flyback converter, the present application can realize the improvement of cross regulation by only adding a cross regulation capacitor, without using a complex sampling and control algorithm, the implementation is simple, and the control and driving mode of the original circuit is not affected, the problem of uneven energy distribution caused by load disturbance is solved, the self-voltage balancing effect of the bipolar output circuit is realized, the voltage deviation is reduced, and it is suitable for occasions requiring bipolar voltage power supply.

The invention discloses a vibration capacitance type high-voltage static measurement probe suitable for an inclined curved surface. The vibration capacitance type high-voltage static measurement probe comprises a vibration capacitance type static probe, an amplitude-stabilized oscillator, a signal amplifier, an amplitude comparator, an adjustable direct-current voltage stabilization module, a bipolar voltage amplification module, a voltage superposition module and a voltage display module. One end of the cantilever beam is fixedly connected with the shell, the free end of the cantilever beam extends to the end face, a first piezoelectric element is arranged on the cantilever beam, and a sensitive electrode exposed through an opening is arranged at the free end of the cantilever beam; the amplitude-stabilized oscillator drives the piezoelectric element to enable the cantilever beam to vibrate, the sensitive electrode outputs a signal in direct proportion to the potential difference of the surface to be measured and the probe, and the signal is amplified by the signal amplifier and then transmitted to the amplitude comparator; the amplitude comparator regulates and controls the output of the two voltage modules, the voltage superposition module superposes the voltage of the two voltage modules and then applies the superposed voltage to the probe, and the voltage display module monitors the superposed voltage. The inclined curved surface can be measured without rotating the probe, concentrated discharge of an electric field is avoided, and wide-range and high-precision rapid continuous measurement is realized.

The application discloses a kind of based on the flexible direct current line differential protection method and system of berilong line mode differential integral current, by obtaining the geometric parameter of direct current line, calculating frequency variable polar domain impedance and admittance matrix, and selecting the line mode wave impedance, resistance and propagation coefficient under specific frequency;Real-time acquisition of the bipolar voltage and current at the two ends of line, after obtaining line mode by polar mode transformation, the line mode current of line reference point is accurately calculated using berilong model;Through band-pass filtering to suppress noise, and through optical fiber channel to realize the synchronization and compensation of two-end data;The sum of the reference point current at both ends is taken to generate the berilong line mode differential current, and then the line mode differential integral current is obtained by integrating the cumulative data window;Finally, the fault is determined by comparing the integral current with the action threshold value.The application solves the problem of single ground fault identification, and is suitable for reliable protection of flexible direct current line in new energy access scenario.

This invention discloses a high-gain bidirectional converter and its control method, belonging to the field of converter technology, including: a first inductor L1, a second inductor L2, first to fifth switching transistors S1 to S5, and first to M+1 diodes D. B1～ D Bm+1 The invention comprises first to Mth SM1 (sub-module) units and first to Nth SM2 units, wherein the SM1 unit is a half-bridge MMC (Modular Multilevel Converter) module, and the SM2 unit is a rechargeable and bidirectional discharge MMC sub-module; it also includes an output voltage step amplitude sampling stage, a transfer function calculation stage, a carrier stage, a comparison stage, a delay stage, and a drive signal generation stage. This invention can significantly increase voltage gain while suppressing charging current peaks and reducing charging losses, and achieves closed-loop control of bipolar voltage with a single voltage sensor.

The application belongs to the technical field of semiconductor processing, and particularly relates to an electrostatic chuck power supply with independent bias voltage, a suction device and a control method. The power supply comprises a direct current high voltage module and a first power supply polarity switching module connected in sequence, the first power supply polarity switching module outputs a bipolar voltage used for suction of an electrostatic chuck, and further comprises a control module, a bias voltage module and a second power supply polarity switching module, the output end of the second power supply polarity switching module is electrically connected with the direct current high voltage module; the bias voltage module acquires a direct current input voltage and outputs a bias voltage to the second power supply polarity switching module, the second power supply polarity switching module switches the polarity of the bias voltage and outputs the bias voltage to the direct current high voltage module under the control of the control module, and meanwhile the bias voltage can also be independently output as a voltage source. The bias voltage can meet the dynamic adjustment requirement in the wafer suction process and is suitable for application scenarios requiring independent use of the bias voltage.