32results about How to "Protection against surge voltage" patented technology

There is provided a matrix converter apparatus including both functions of outputting a step up voltage and outputting a step down voltage. In a matrix converter apparatus for directly connecting respective phases of a three phase alternating current power source (1) and respective phases of an output side by a bidirectional switch constituted by IGBT transistors or the like connected reversely in parallel therewith, controlling to output an alternating current power source voltage by a PWM control based on an output voltage instruction, and outputting an arbitrary direct current or alternating current voltage, respective reactors (61), (62), (63) inserted to be connected between the respective phases of the polyphase alternating current power source 1 and the bidirectional switches are included, and by controlling to ON / OFF the bidirectional switches, terminals of two or more of the reactors on a side of the bidirectional switch are shortcircuited, and thereafter opened to thereby step up an output voltage of the matrix converter apparatus. Further, when the terminals are switched from being shortcircuited to being opened, conduction paths of currents flowing in the respective reactors which have been shortcircuited are ensured by controlling to ON / OFF the bidirectional switch group (5) and a capacitor group (7).

In an isolated switching power supply apparatus, by performing on / off control of a first switching device and a second switching device, energy is transmitted from the primary side to the secondary side using a second primary winding and a second secondary winding while the first switching device is on, and energy is transmitted by a first primary winding and a first secondary winding while the second switching device is on. The first secondary winding and the second secondary winding are connected in series with one another, and an inductor is inserted in series to the second secondary winding. An output current is made to flow through the inductor irrespective of whether the first switching device is on or the second switching device is on.

Provided is a driving circuit which suppresses a surge voltage at the time of switching a power semiconductor element and reduces switching loss. An element (10) such as an IGBT and another element (20) to be paired are connected, the element (10) is driven by a driver (22), and a gate voltage is controlled by a control circuit (24). When the power semiconductor element is turned off, a comparator (26) detects that a voltage (Vak) of the element (20) is a prescribed voltage, the control circuit (24) switches gate resistance from low resistance to high resistance to suppress the surge voltage, and the switching loss is reduced. When the power semiconductor element is turned on, start up of the voltage (Vak) is detected, and the control circuit (24) switches the gate resistance from high resistance to low resistance after a prescribed time to suppress the surge voltage, and the switching loss is reduced.

There is provided a matrix converter apparatus including both functions of outputting a step up voltage and outputting a step down voltage. In a matrix converter apparatus for directly connecting respective phases of a three phase alternating current power source (1) and respective phases of an output side by a bidirectional switch constituted by IGBT transistors or the like connected reversely in parallel therewith, controlling to output an alternating current power source voltage by a PWM control based on an output voltage instruction, and outputting an arbitrary direct current or alternating current voltage, respective reactors (61), (62), (63) inserted to be connected between the respective phases of the polyphase alternating current power source 1 and the bidirectional switches are included, and by controlling to ON / OFF the bidirectional switches, terminals of two or more of the reactors on a side of the bidirectional switch are shortcircuited, and thereafter opened to thereby step up an output voltage of the matrix converter apparatus. Further, when the terminals are switched from being shortcircuited to being opened, conduction paths of currents flowing in the respective reactors which have been shortcircuited are ensured by controlling to ON / OFF the bidirectional switch group (5) and a capacitor group (7).

A diode includes an anode electrode layer; a cathode electrode layer; a buffer layer of a first conductivity type formed between the anode electrode layer and the cathode electrode layer in a region extending to a location at a distance of 30 μm or more from the cathode electrode layer; a first semiconductor layer of the first conductivity type formed in a region between the anode electrode layer and the cathode electrode layer, and being in contact with the buffer layer of the first conductivity type; and a second semiconductor layer of a second conductivity type formed in a region between the anode electrode layer and the first semiconductor layer of the first conductivity type. The carrier concentration in the first semiconductor layer is lower than the carrier concentration in the buffer layer. The carrier concentration in the buffer layer is less than 1×1015 cm−3.

The invention discloses a high-speed large-current power field-effect transistor driving circuit, which comprises a driving pre-circuit, a totem-pole circuit, and a driving post-circuit, wherein the driving pre-circuit comprises a capacitor C1, resistors R1, R2 and R3, a diode D1 and triodes T1 and T2; the totem-pole circuit consists of diodes D2 and D3, resistors R4 to R11, a capacitor C2 and field-effect transistors Q1 and Q2; the driving post-circuit consists of resistors R12 and R13, diodes D4 and D5, a capacitor C3 and a field-effect transistor Q3; the driving pre-circuit is connected with a driving signal Vg, the driving post-circuit is connected with a driving object Q3, and the totem-pole circuit is connected with the driving pre-circuit and the driving post-circuit. The driving circuit is simple in structure, low in cost, large in output current and high in load-carrying capacity, and can meet the requirement on the high-speed low-voltage large-current driving on the field-effect transistors under specific situations.

A control apparatus controls an optimizer that steps up a DC input voltage from a solar photovoltaic power generation panel to a predetermined DC high voltage and converts the stepped-up DC voltage into a grid connection voltage, and includes a microprocessor; a sensor group; and a MOS driver group. The microprocessor includes: a control logic unit; a maximum power point tracking control unit; a PWM control unit; a PFM control unit; an I / O port; a timer control unit; and an initial measurement unit. The sensor group includes a solar photovoltaic panel voltage detection circuit; a solar photovoltaic panel current detection circuit; an optimizer output voltage detection circuit; and an optimizer output current detection unit. Thus, even when the solar photovoltaic power generation panel is at a low power in a low output state, stable operation can be continued, and transistors can be protected from a surge voltage.

The invention provides a DC to DC converting circuit, comprising: a transforming unit with a primary winding and a secondary winding; a bridge rectifier unit coupled to an input voltage, having a first output terminal and a second output terminal coupled to both side of the primary winding respectively; a first switch coupled between the input voltage and the first output terminal; a second switch coupled between the first output terminal and a ground terminal; a third switch coupled between the input voltage and the second output terminal; and a fourth switch coupled between the second output terminal and the ground terminal; an output unit paralleled to the secondary winding; and a clamping unit coupled to the input voltage and paralleled to the bridge rectifier unit, having an auxiliary switch coupled to the input voltage; and a clamping capacitor coupled between the auxiliary switch and the ground terminal; wherein the auxiliary switch is turned on when operation statuses of the first switch and the fourth switch or the second switch and the third switch are changed.

The purpose of the present invention is to prevent, with a simple circuit configuration, an after-flash from occurring and a large surge voltage from occurring in a primary winding when opening between welding electrodes between which excitation current is flowing. In a capacitor type welding method according to the present invention, electric charges charged on a welding capacitor are discharged and when the discharge current is brought into a state in which the discharge current does not substantially flow through a discharge switch, excitation current that has been flowing through the primary winding of a welding transformer is transferred to the secondary winding thereof. When opening between a first welding electrode and a second welding electrode while the transferred excitation current is flowing through the secondary winding, the discharge switch is brought into a state in which the discharge switch can be turned on by applying a drive signal thereto. Surge voltage occurring in the primary winding of the welding transformer when opening between the first and second welding electrodes is thereby flowed through the discharge switch to the welding capacitor as surge current.

The invention relates to one dry reactor, which comprises coil, shield device and column isolation device, wherein, the coil two ends are symmetrically set with shield devices connected by glue beam inside coil; the coil down end shield device is fixed with column isolation device. The invention has the following advantages: lowering coil end electrical field; avoiding long time product operationdust pile up; ensuring reliable operation; improving the shield device distribution.

A solar photovoltaic output optimizer circuit includes a PV input device for receiving output of a solar photovoltaic panel; a switching device for converting a DC voltage input through the PV input device into a predetermined pulse voltage or AC voltage; and a voltage doubler rectification device for stepping up power output of the switching device to a predetermined voltage. The PV input device includes: an inductance L1 connected in series to “+” output of the PV panel; and a surge protection circuit that is connected in parallel to the inductance L1, operates so as to absorb surge voltage to occur in output of the inductance L1 only when output of the PV panel is small and normal control cannot be performed, and is automatically separated from the inductance L1 when the output of the PV panel is large.

The invention discloses an anti-reverse connection system and method applied to battery management unit equalization channels. The anti-reverse connection system comprises a first interface, a second interface and a field-effect tube, wherein the first interface comprises a first anode and a first cathode; the second interface comprises a second anode and a second cathode; the first anode is connected with the second anode; a grid electrode of the field-effect tube is connected with the first anode, a drain electrode of the field-effect tube is connected with the first cathode, and a source electrode of the field-effect tube is connected with the second cathode. The anti-reverse connection system is controlled by adopting the switching characteristic of the field-effect tube, so that an anti-reverse connection circuit is realized; next, the circuit loss of the part is reduced by using voltage control of the field-effect tube and the characteristic of small on resistance; and then, bidirectional flow of current is realized by using the characteristic of bidirectional conduction after the field-effect tube is connected, and the anti-reverse connection system is applicable to bidirectional equalization channels of battery packs. The anti-reverse connection system can be widely applied to various bidirectional current anti-reverse connection circuit systems.

In a power converter, a plurality of semiconductor devices and a plurality of cooling plates are stacked. The plurality of semiconductor devices includes a first-first sealed semiconductor device, a second-first sealed semiconductor device, and a plurality of second sealed semiconductor devices. The first-first sealed semiconductor device has a first high potential side terminal, and a first low potential side terminal. The second-first sealed semiconductor device has a second high potential side terminal, and a second low potential side terminal. When viewed along a stacking direction, the first high potential side terminal is disposed to overlap with the second low potential side terminal.

The application discloses an overvoltage protection circuit and power supply equipment, wherein the overvoltage protection circuit is composed of a MOS transistor, a bias module and a control module, and when the voltage at both ends of the load does not exceed the overvoltage protection point, the control The module controls the MOS tube to be in a fully conducting state. At this time, the voltage at both ends of the load is equal to the input power supply voltage; when the voltage at both ends of the load exceeds the overvoltage protection point, the control module controls the MOS tube to enter a linear conduction state , the voltage at both ends of the MOS tube increases, thereby reducing the voltage at both ends of the load, so that the voltage at both ends of the load is lower than the input power supply voltage, so as to avoid the load being affected by surge voltage or overvoltage, and the MOS tube is in the presence of surge voltage or overvoltage , always keep the voltage at both ends of the load at the overvoltage protection point, and achieve the purpose of stabilizing the voltage provided to the load at the overvoltage protection point when a surge voltage or overvoltage occurs.

Disclosed is a rectifying device provided with a standby power reduction function. When a voltage of unsmoothed DC power, which is output from a rectifying unit that rectifies AC power, is lowered to be equal to or smaller than a discharge reference voltage at a time around a zero-crossing point of the AC power, the present invention can instantaneously discharge a capacitor, which has been charged with the unsmoothed DC power, to be synthesized with the unsmoothed DC power, and thus supply stable DC power to a load without using an electrolytic capacitor. In particular, the present invention can adjust a resistance value of a surge prevention switch connected in series with the capacitor to control a current amount flowing through the capacitor, and thus can prevent a surge voltage from being generated when charging and discharging the capacitor.

The invention relates to a method for preventing a surge used for an electronic jacquard machine. The electronic jacquard machine consists of a control system and a plurality of electromagnetic needle-selector drive plates controlled by the control system. Each electromagnetic needle-selector drive plate drives a plurality of electromagnetic needle-selector coils. A time-delay unit is connected with the branch circuit, which is connected with the electromagnetic needle-selector drive plate, in sequence, each branch circuit has a different delay time and the delay time of a plurality of branchcircuits forms a time-delay sequence. When the control system needs the electromagnetic needle-selector coil to be electrified, the electromagnetic needle-selector coils connected with the branch circuits are electrified in sequence under the control of the time-delay unit. When the control system needs the electromagnetic needle-selector coil to be powered-down, the electromagnetic needle-selector coils connected with the branch circuits are powered-down in sequence under the control of the time-delay unit. The method can effectively reduce the surge current and surge voltage due to the factthat the loads are electrified or powered-down at the same time.

The invention provides a DC to DC converting circuit, comprising: a transforming unit with a primary winding and a secondary winding; a bridge rectifier unit coupled to an input voltage, having a first output terminal and a second output terminal coupled to both side of the primary winding respectively; a first switch coupled between the input voltage and the first output terminal; a second switch coupled between the first output terminal and a ground terminal; a third switch coupled between the input voltage and the second output terminal; and a fourth switch coupled between the second output terminal and the ground terminal; an output unit paralleled to the secondary winding; and a clamping unit coupled to the input voltage and paralleled to the bridge rectifier unit, having an auxiliary switch coupled to the input voltage; and a clamping capacitor coupled between the auxiliary switch and the ground terminal; wherein the auxiliary switch is turned on when operation statuses of the first switch and the fourth switch or the second switch and the third switch are changed.

The invention provides a power-stealing-preventing power supply circuit. Two grades of RC filtering are additionally applied to the front end of a voltage stabilizing chip, and impact voltage at the front end of the voltage stabilizing chip can be removed when an electric stick is electromagnetically radiated, so that the effect of protecting the voltage stabilizing chip is realized; two grades of the RC filtering are additionally applied to the rear end of the voltage stabilizing chip, so that impact voltage at the rear end of the voltage stabilizing chip can be removed during electromagnetic radiation and the voltage stabilizing chip is protected; and furthermore, the whole circuit is not influenced by the impact voltage when the electric stick is electromagnetically radiated, halting and resetting phenomena of an electric energy meter are not caused and the loss of electric quantity also can be prevented.

An ac generator for a vehicle includes a rotor for providing a magnetic field, a stator having a stator core in which a plurality of phase-windings is mounted to generate electromotive force when the magnetic field is supplied, a rectifying unit which includes positive electrode side rectifying elements and negative electrode side rectifying elements respectively connected to the plurality of phase-windings. One of the positive electrode side rectifying element and negative electrode side rectifying element that is connected to a portion of the phase-windings is constituted of a single element and the remainders are constituted of parallelly connected two elements.

The invention discloses a high-speed large-current power field-effect transistor driving circuit, which comprises a driving pre-circuit, a totem-pole circuit, and a driving post-circuit, wherein the driving pre-circuit comprises a capacitor C1, resistors R1, R2 and R3, a diode D1 and triodes T1 and T2; the totem-pole circuit consists of diodes D2 and D3, resistors R4 to R11, a capacitor C2 and field-effect transistors Q1 and Q2; the driving post-circuit consists of resistors R12 and R13, diodes D4 and D5, a capacitor C3 and a field-effect transistor Q3; the driving pre-circuit is connected with a driving signal Vg, the driving post-circuit is connected with a driving object Q3, and the totem-pole circuit is connected with the driving pre-circuit and the driving post-circuit. The driving circuit is simple in structure, low in cost, large in output current and high in load-carrying capacity, and can meet the requirement on the high-speed low-voltage large-current driving on the field-effect transistors under specific situations.

A switching power supply apparatus includes a first series circuit including a third rectifier device and a fourth rectifier device and that is connected between a positive output terminal and a negative output terminal, and a first capacitor a first end of which is connected to a connection node between the third rectifier device and the fourth rectifier device and a second end of which is connected to an end, not connected to the first series circuit, of a first rectifier device or a second rectifier device. The first series circuit and the first capacitor define a snubber circuit.

The invention discloses computing power equipment. The computing power equipment comprises a shell, a power supply module, a back plate, a computing power module, a switching circuit, a slow start circuit and a control device; the power supply module is connected with an external power supply and supplies power to the computing power equipment; the back plate is fixed on the shell; a connector module is arranged; and the computing power module is detachably connected with the back plate through the connector module. One end of the switching circuit is connected with the power module, and the other end is connected with the computing power circuit; one end of the slow start circuit is connected with the power supply module, and the other end is connected with the switch circuit. The control device is electrically connected with the back plate, the slow start circuit and the computing power module. And when the computing power equipment is in a working state and the computing power module is detected to be inserted into the connector module of the back plate, the switching circuit is controlled to be turned on through the slow start circuit, so that the power supply module powers on the computing power module through the switching circuit and the connector module. And the surge voltage of the computing power equipment when the computing power module is plugged and unplugged is reduced.

An LDO (low dropout regulator) comprises anovervoltage power device, a voltage detection circuit, a first control circuit and a second control circuit, wherein the voltage detection circuit is suitable for detecting power voltage to produce a detection signal, and the detection signal is output by the voltage detection circuit; the first control circuit is suitable for controlling the detection signal according to a control signal, so that the detection signal is of first logic level in preset time interval after power on and is of second logic level different from the first logic level after the preset time interval; the second control circuit is suitable for controlling the overvoltage power device according to the detection signal, controls the overvoltage power device to be switched off in response to the detection signal being of the first logic level and removes control on the overvoltage power device in response to the detection signal being of the second logic level. Surge voltage output by the LDO can be inhibited effectively with adoption of the scheme.

A control apparatus controls an optimizer that steps up a DC input voltage from a solar photovoltaic power generation panel to a predetermined DC high voltage and converts the stepped-up DC voltage into a grid connection voltage, and includes a microprocessor; a sensor group; and a MOS driver group. The microprocessor includes: a control logic unit; a maximum power point tracking control unit; a PWM control unit; a PFM control unit; an I / O port; a timer control unit; and an initial measurement unit. The sensor group includes a solar photovoltaic panel voltage detection circuit; a solar photovoltaic panel current detection circuit; an optimizer output voltage detection circuit; and an optimizer output current detection unit. Thus, even when the solar photovoltaic power generation panel is at a low power in a low output state, stable operation can be continued, and transistors can be protected from a surge voltage.

The invention relates to an acousto-optic integrated independent wireless gas detector system and an integrated control switch for controlling a solenoid valve linked with the gas detector, which mainly includes a first light emitting diode D1, a second light emitting diode D2, The third light-emitting diode D3, the first switch SW1, the second switch SW2, the third switch SW3, the zero-crossing detection circuit ZC, the first rectification and filtering circuit DC1, the second finishing and filtering circuit DC2, the first driving part DM1, the second driving Part DM2, first shield SH1, second shield SH2, first permanent magnet PM1, second permanent magnet PM2, first mesh plate MS1, second mesh plate MS2, third mesh plate MS3, fourth mesh plate Mesh plate MS4, notch, slider, square block, groove, support.

The invention discloses a power supply system of an electronic-gun power supply, comprising an electronic-gun lamp filament and a lamp filament transformer, wherein a primary coil of the lamp filament transformer is connected with a high-voltage electrode, and a secondary coil of the lamp filament transformer is connected with the electronic-gun lamp filament; at least one potentiometer is also connected between the primary coil of the lamp filament transformer and the high-voltage electrode; each potentiometer adjusts the resistance value of the potentiometer by insulating rods; and the insulating rods are driven by stepping motors. The power supplying system disclosed by the invention has the advantages that the problem that the common power supply in the prior art can not finish power supply to the electronic gun is solved, and the primary current of the lamp filament transformer is adjusted by adjusting two potentiometers of a primary loop of the lamp filament transformer so as to change the high-frequency current of the lamp filament and achieve the purpose of adjusting the intensity of electron flow of an accelerator; the adjustment of electron beam flow is convenient, the stability of the electron beam flow is good, and the problem that the power is supplied to the electronic gun at a high-potential position is well solved.

The invention relates to an acousto-optic integrated independent wireless gas detector system and an integrated control switch for controlling an electromagnetic valve linked with a gas detector. The system mainly comprises a first light-emitting diode D1, a second light-emitting diode D2, a third light-emitting diode D3, a first switch SW1, a second switch SW2, a third switch SW3, a zero-cross detection circuit ZC, a first rectification filter circuit DC1, a second rectification filter circuit DC2, a first driving part DM1, a second driving part DM2, a first shielding part SH1, a second shielding part SH2, a first permanent magnet PM1, a second permanent magnet PM2, a first grid plate MS1. a second grid plate MS2, a third grid plate MS3, a fourth grid plate MS4, a notch part, a sliding block, a square block, a groove and a supporting part.