35results about How to "Good overvoltage protection" patented technology

An open drain driver ( 7 ) selectively switches a MOSFET switch (MN 1 ) which is passively held in the conducting state into the non-conducting state. The MOSFET switch (MN 1 ) switches an AC analogue input signal on a main input terminal ( 3 ) to a main output terminal ( 4 ) and the gate of the MOSFET switch (MN 1 ) is AC coupled by a capacitor (C 1 ) to the drain thereof. The open drain driver ( 7 ) comprises a first MOSFET (MN 2 ) and a second MOSFET (MN 3 ) through which the gate of the MOSFET switch (MN 1 ) is pulled to ground (Vss). The gate of the first MOSFET (MN 2 ) is coupled to the supply voltage (VDD) for maintaining the first MOSFET (MN 2 ) in the open state. A control signal is applied to the gate of the second MOSFET (MN 3 ) for selectively operating the open drain driver ( 7 ) in the conducting state for operating the MOSFET switch (MN 1 ) in the non-conducting state. When the second MOSFET (MN 3 ) is in the non-conducting state, the first MOSFET (MN 2 ) remains in the conducting state until the voltage on a coupling node ( 9 ) between the first and second MOSFETs (MN 2 ,MN 3 ) equals the difference between its gate voltage and its threshold voltage, at which stage, any over-voltages applied to the gate of the MOSFET switch (MN 1 ) are divided between the first and second MOSFETs (MN 2 ,MN 3 ). A coupling diode (D 1 ) coupling the coupling node ( 9 ) to the supply voltage (VDD) clamps the voltage on the coupling node ( 9 ) at the supply voltage (VDD) plus the conducting voltage of the diode (D 1 ), in the event of the voltage on the coupling node ( 9 ) rising after the first MOSFET (MN 2 ) has gone into the non-conducting state. The coupling node ( 9 ) may be capacitively coupled to the supply voltage (VDD) by a coupling capacitor instead of or as well as the diode (D 1 ) for limiting the voltage on the coupling node ( 9 ).

An open drain driver (7) selectively switches a MOSFET switch (MN1) which is passively held in the conducting state into the non-conducting state. The MOSFET switch (MN1) switches an AC analogue input signal on a main input terminal (3) to a main output terminal (4) and the gate of the MOSFET switch (MN1) is AC coupled by a capacitor (C1) to the drain thereof. The open drain driver (7) comprises a first MOSFET (MN2) and a second MOSFET (MN3) through which the gate of the MOSFET switch (MN1) is pulled to ground (Vss). The gate of the first MOSFET (MN2) is coupled to the supply voltage (VDD) for maintaining the first MOSFET (MN2) in the open state. A control signal is applied to the gate of the second MOSFET (MN3) for selectively operating the open drain driver (7) in the conducting state for operating the MOSFET switch (MN1) in the non-conducting state. When the second MOSFET (MN3) is in the non-conducting state, the first MOSFET (MN2) remains in the conducting state until the voltage on a coupling node (9) between the first and second MOSFETs (MN2,MN3) equals the difference between its gate voltage and its threshold voltage, at which stage, any over-voltages applied to the gate of the MOSFET switch (MN1) are divided between the first and second MOSFETs (MN2,MN3). A coupling diode (D1) coupling the coupling node (9) to the supply voltage (VDD) clamps the voltage on the coupling node (9) at the supply voltage (VDD) plus the conducting voltage of the diode (D1), in the event of the voltage on the coupling node (9) rising after the first MOSFET (MN2) has gone into the non-conducting state. The coupling node (9) may be capacitively coupled to the supply voltage (VDD) by a coupling capacitor instead of or as well as the diode (D1) for limiting the voltage on the coupling node (9).

An overvoltage protection circuit may include a reference voltage generator, a trigger circuit, and a clamping device. The reference voltage generator is for providing a reference voltage that is relatively constant during a powered EOS / ESD event. The trigger circuit is coupled to receive the reference voltage and a power supply voltage. The trigger circuit is for comparing the reference voltage to the power supply voltage. In response to detecting that the power supply voltage is above the reference voltage, the trigger circuit provides a trigger signal having a voltage proportional to a voltage level of the overvoltage event. The clamping device is coupled between a first power supply terminal and a second power supply terminal. The clamping device is for providing a current path between the first and second power supply terminals in response to the trigger signal.

An overvoltage protection element (1) includes a housing (2), two terminals (3, 4) for electrical connection of the overvoltage protection element (1) to current or signal paths to be protected, and an arrester (5, 6), including a varistor, located within the housing (2). In addition to providing a simple structure and installation, the overvoltage protection element (1) is especially well adapted to thermal and dynamic loads, so that no damage to the overvoltage protection element (1) occurs to the outside, wherein the housing (2) includes two metal shells (7, 8) electrically connected to a terminal region (9, 10) of the arrester (5, 6).

The invention relates to modifying structure of overvoltage open circuit protector. The protector includes varistor layer, electrode connected, and temperature sensing layer and output lead. The said temperature-sensing layer sets up outside varistor layer combining the two layers as an integrated layer. The invention possesses features of simple structure, easy production, low cost, good performance of overvoltage protection and long service life. The invention is suitable for fabricating productions of overvoltage protection in different specifications.

The semiconductor chip of overvoltage protector in low capacitance includes intermediate layer on N silicon substrate, as well as base region, emitter region and short dot placed on surface on two sides symmetrical to intermediate layer on N silicon substrate. Characters are that chip is in roundness, and there are etch grooves on peripheries on up and low surfaces of rounded chip. Rounded structural design increases effective area of emitter region, eliminates redundant boron diffusion areas. Thus, the invention possesses relative lower capacitance, satisfies requirement of electrical parameters of circuit, and good effect of overvoltage protection. Moreover, rounded design can increase effective usable floor area on rounded silicon wafer through reasonable repeated composition.

A power transmitter (101) of a wireless power transfer system comprises a resonance including a transmitter coil (103) for generating a power transfer signal for wirelessly transferring power to a power receiver (105). Further, a driver (1303) generates a drive signal for the resonance circuit (201) and a message receiver (1305) is arranged to receive messages from the power receiver (105). A power loop controller (1307) implements a power control loop by adapting the power of the drive signal in response to power control messages received from the power receiver (105). However, the regulation is subject to a constraint of at least one of a current or voltage of the resonance circuit and a power of the drive signal being below a maximum limit. Further, the power transmitter (101) comprises an adapter (1309) which adapts the maximum limit in response to a load indication indicative of a loading of the power transfer signal by the power receiver (105).

A generator for producing high voltages and having at least one generator winding (12) is connected via a generator circuit (10) to a network (19), which generator circuit has means (15, . . . , 17) for protection against overvoltages. Improved protection against higher voltages is achieved in that the at least one generator winding (12) is subdivided into a number of winding sections (12a-c) whose winding insulation is designed such that the insulation level is graduated, and in that the overvoltage protection means have a number of overvoltage protection elements (15, . . . , 17), which are associated with the respective individual winding sections (12a-c) and whose response levels are matched to the requirements of the associated winding section.

The invention belongs to the technical field of mechanical and electrical integration, and relates to a touch type monitor capable of achieving active informing when a fault occurs. The touch type monitor is jointly composed of a fault monitoring power circuit, a lock hole cover plate, an alarm starting switch, a touch type circuit and a videography and warning circuit. The lock hole cover plate covers a lock hole switch and a lock hole together. When an event occurs, a tough signal is generated once the hand touches the lock hole cover plate, and after the touch signal is amplified through the touch type circuit, the videography and warning circuit is started to achieve videography and warning; and for events which cannot be stopped, either the lock hole continues to be opened or a door is barbarously burst open, the alarm starting switch immediately acts, the videography and warning circuit is started to achieve videography and warning, the fault monitoring power circuit is used in cooperation, and when the touch type monitor breaks down, the important functions of protection and display are achieved; and the problem that a burglar alarm is damaged so that an alarm cannot be given when an event occurs does not need to be considered any more, and the security performance of antitheft products is improved.

The invention relates to a three-function automatically switched matching power supply and belongs to the technical field of electronics. The three-functions automatically switched matching power supply comprises a DC rectification unit, an AC rectification unit, a switch lightning protection unit, an AC operating unit, an AC backup unit, a load unit, a storage battery, a charging unit, an isolation unit, a conversion control unit, and a silicon controlled rectifier (SCR) conversion unit. The OR-gate diodes of the two rectification units are connected to the switch lightning protection unit. The switch lightning protection unit is formed by a lightning protection relay and a lightning protection voltage-stabilizing tube connected in series. The lightning protection voltage-stabilizing tube generates protection during overvoltage. The AC rectification unit output supplies current to an AC power supply unit and the conversion control unit. The DC rectification unit output supplies current to the charging unit. When the load unit is connected and AC power is provided, the conversion control unit is started and the SCR conversion unit is switched off so as to achieve an AC power supply circuit. When no AC power is provided, the conversion control unit is cut off and the SCR conversion unit is activated so as to achieve a DC power supply circuit. A three-terminal integrated circuit supplies power in a normal state. The three-function automatically switched matching power supply has all advantages of a three-terminal integrated circuit.

The invention relates to a high potential gate control device for a series thyristor valve block in an SVC (Static Var Compensator). The device comprises a plurality of gate control modules, a control unit, an energy acquiring unit, a photoelectric conversion unit, a voltage detection unit and a protection unit, wherein each gate control module is used for controlling two thyristors which respectively correspond to the gate control module; the control unit is used for triggering the thyristors according to a trigger command, acquiring and transmitting state information of the thyristors to the photoelectric conversion unit and transmitting alarm information according to detection information of the voltage detection unit; the energy acquiring unit is used for supplying power to the control unit; the photoelectric conversion unit is used for photoelectrically converting and uploading the rexeived trigger command and the state information of the thyristors; the voltage detection unit is used for detecting the voltage of the energy acquiring unit and transmitting the detection information to the control unit; and the protection unit is used for carrying out voltage breakdown protection on the thyristors. The device disclosed by the invention has the advantages of high integrated level, high reliability and low power consumption and can be used for providing sound control and protection for a high-voltage series thyristor valve block in the SVC system.