39results about "Emergency protective arrangements for limiting excess voltage/current" patented technology

Systems and methods are disclosed for detecting balanced electrical leakage between a power source and a machine frame. In one embodiment, a balanced fault detection system for a machine includes a power source that is electrically insulated from a machine frame and a leakage detection switch that is connected to a ground. The balanced fault detection system also includes a leakage detection resistor that is interposed between a power source terminal and the switch having a leakage detection resistance. The balanced fault detection system further includes a voltage measuring device that measures voltages of the power source at positive and negative voltage sides of the ground and a leakage calculator that calculates a leakage resistance of the machine based on the measured voltages at the positive and negative voltage sides and the leakage detection resistance.

A closing phase that produces the smallest energization flux error at a connection input point is calculated based upon a residual flux of the first closing phase and the preliminarily given pre-arc characteristic and closing time deviation characteristic of a three-phase circuit breaker, so that the calculated phase value is set as a target closing phase of the first closing phase. A closing phase that produces the smallest energization flux error when a residual flux of zero is calculated, so that the calculated phase value is set as a target closing phase of the remaining two phases. The total time required from the reference point to the target closing phases of the remaining two phases and a delay time corresponding to an integer multiple of a given cycle of the three-phase power supply is set as a target closing time of the remaining two phases.

Circuits, systems, and methods for protecting an integrated circuit device having a first power rail and a second power rail from electrostatic discharge (ESD) events. The ESD protection circuit generally comprises an ESD shunt device coupled to the first power rail and a ground potential, a bias circuit configured to provide a bias voltage to the ESD shunt device during a normal mode of operation and to disable the bias voltage during an ESD event on the first power rail, and an isolation circuit configured to isolate the second power rail from the ESD shunt device during the normal mode of operation and to couple the second power rail to the ESD shunt device during an ESD event on the second power rail. The present invention advantageously provides ESD protection that can be shared by independent power supply rails with minimal current leakage through the ESD device, thereby reducing the total number of ESD protection circuits on a mixed supply integrated circuit device.

A circuit for attenuating a surge is disclosed that might include a conductor for receiving the surge, a capacitor, positioned along the conductor, for blocking the surge, and a gas tube having a first end coupled to the conductor and a second end coupled to a ground. The circuit might also include a transformer having a first wire and a second wire, the transformer being coupled to the conductor, a resistor coupled to the first and second wires of the transformer, a varistor coupled to the first wire of the transformer, and a diode coupled to the second wire of the transformer.

According to one embodiment, a digital protection relay includes an auxiliary transformer (2) which decreases a voltage of an electrical signal from a main circuit transformer (1) to a predetermined voltage; a detection resistance circuit (20) including a Π-type or T-type circuit including an input connected to an output of the auxiliary transformer (2); an analog detection circuit (3) which is connected to an output of the detection resistance circuit (20) and detects a quantity of electricity of an electrical signal from the auxiliary transformer (2); an A/D conversion circuit (4) connected to the analog detection circuit (3); a central processing device 5 which is connected to the A/D conversion circuit (5) and performs a protection operation; and a trip output contact (9) which is closed by processing of the central processing device (5) and operates an external breaker (21). In the digital protection relay, an input contact terminal 11 for inputting a test signal with a constant voltage from an external test device (13) to the analog detection circuit (3) as a signal corresponding to an output of the auxiliary transformer (2) is provided between the detection resistance circuit (20) and the analog detection circuit (3).

The invention discloses a novel design method for ESD protection, which comprises the following steps: (1) forming a well region, a gate oxide layer, gate poly-silicon, a porous medium layer, a source electrode and a grid electrode on a silicon substrate of a DMOS device in order; (2) forming the gate poly-silicon under lead bores of the source electrode and the grid electrode; and (3) forming the gate oxide layer between the gate poly-silicon and the well region, wherein the gate oxide layer is used for isolating the source electrode and the grid electrode when the lead bores of the source electrode and the grid electrode are punched at the position of the gate poly-silicon. The novel design method has the remarkable characteristics of utilizing the same set of MASK to produce products with ESD or without ESD by selecting whether to increase a process for photoetching an ESD layer, so as to save MASK cost and greatly save the production cost of the products.

Apparatus and method for draining stored power are disclosed, which the apparatus and method are applied to an EMI filter circuit for draining power. When the power supply circuit is not working, the apparatus provides a bleeder resistor to drain the power stored in the capacitors of the EMI filter circuit. On the other hand, when the power supply circuit is working, the apparatus provides an open-circuit resistor which has extremely large electrical resistance in order to stop draining power. Thus, the apparatus for draining stored power will not cause extra power waste.

An electrostatic discharge protection apparatus comprises a stack arrangement having a first electrostatic discharge protection element and a second electrostatic discharge protection element. The stack arrangement is arranged to provide a bias potential between the first and second electrostatic discharge protection elements. In one embodiment, the bias potential can be achieved by a clamp arrangement coupled across the stack arrangement.

The invention discloses an overcurrent protection circuit and an air conditioner. The overcurrent protection circuit comprises an overcurrent protection circuit bus and an overcurrent protection unit,wherein the overcurrent protection unit comprises a sampling circuit and a report circuit, the sampling circuit is used for acquiring a current signal of a protected circuit, the report circuit is used for determining whether overcurrent occurs in the protected circuit according to the current signal acquired by the sampling circuit and outputting a protection action signal to the overcurrent protection circuit bus when the overcurrent occurs in the protected circuit, the protection action signal is output to the protected circuit by the overcurrent protection circuit, overcurrent protectionon the protected circuit is achieved, and a decoupling circuit is used for filtering a surge current signal in the overcurrent protection circuit bus so as to maintain voltage stability of the overcurrent protection circuit bus. By the overcurrent protection circuit, the technical problem of fault false report generated by the overcurrent protection circuit in the prior art is solved.

The invention discloses a circuit board with a static protection structure, which comprises an I/O interface, a static protection device, a discharge circuit, a protection ground area and a working ground area. The protection ground area surrounds the outer side of the working ground area, the discharge circuit is connected between the two areas, and the protection ground area at least comprises one positioning hole, wherein the positioning hole is used for fixing the circuit board and introducing the static electricity of the protection ground area into a ground line or the ground; and the ground wire end of the I/O interface is connected with a static protection device and the positioning hole in series in sequence. The danger of static electricity on the circuit can be effectively prevented by using the scheme; because the structure of the circuit board is provided with a circle of unclosed metal conducting layer, electromagnetic interference can also be effectively prevented, and the electromagnetic compatibility of the circuit board is enhanced.

The invention provides a power source preprocessing circuit. The circuit comprises a peak suppressing circuit, a protective circuit, a buffer circuit and a control circuit; the peak suppressing circuit is connected on a power supply bus in parallel; the protective circuit and the buffer circuit are connected in series on the power supply bus; and the control circuit controls the state of the protective circuit by sampling the bus. The invention is designed to solve the technical problems that existing voltage sensitive resistor VSR method and TVS method can only be used in underloading, the application range is narrow, power loss is large in normal use, protective effect is limited, etc. The invention has the advantages of stable work, high safety, and good heat dissipation and reliability.

The invention relates to a tank circuit protected by undervoltage surges. The tank circuit protected by the undervoltage surges comprises an energy-storage capacitor and is characterized in that a positive pole of the energy-storage capacitor is connected with a source electrode of a metal oxide semiconductor (MOS) tube, a drain electrode of the MOS tube is connected with a positive input end of an input power through charge resistance, and a grid electrode of the MOS tube is connected with a positive input end of the input power through drive resistance. A negative pole of the energy-storage capacitor is connected with a negative input end of the input power. The grid electrode of the MOS tube is connected with a positive pole of a voltage-regulator diode, and a negative pole of the voltage-regulator diode is connected with the source electrode of the MOS tube. The tank circuit protected by the undervoltage surges has the advantages that charge currents after being powered on in a flash can not go as far as to be too large, the damage of large currents to the energy-storage capacitor and other electron components can be avoided, the repeated charge-discharge phenomenon can not occur on the energy-storage capacitor when supply voltage shakes, and thus the influence on the service life of the energy-storage capacitor is reduced.

A semiconductor module which includes a plurality of control circuits that respectively drive a plurality of semiconductor elements on and off and a plurality of signal output circuits for the respective control circuits and which output operation status information, where the signal output circuits are respectively provided with signal output terminals having an open-drain configuration, and the signal output terminals each are connected to an internal lead frame on which the power semiconductor elements and the control circuits are mounted.

A three-phase fault current limiter FCL has three spaced apart input terminals for electrically connecting to respective terminals of a transformer. Three output terminals electrically connect FCL with a load circuit which draws load current I_LOAD. FCL includes two longitudinally spaced apart generally circular High Temperature Superconducting (HTS) DC coils which have central generally cylindrical cavities. FCL also includes a longitudinally extending magnetically saturable core which has six like coextensive parallel and elongate posts. Each post includes a first longitudinal portion and, a second longitudinal portion and a third longitudinal portion extending longitudinally oppositely away from the first portion. Each second portion and third portion is received within one of the central cavities. Three copper-based insulated AC coils are each wound about respective first portions for carrying load current I_LOAD between input terminals to respective output terminals. DC coils magnetically bias the core such that, in response to one or more characteristics of the load current I_LOAD, the AC coils move from a low impedance state to a high impedance state.

A lightning filter and electronic equipment are provided. The lightning filter (1) comprises: an inductor connected in series with the transmission line inlet wire of a protected load circuit (2); and a non-linear voltage limiting element connected in parallel between two transmission line inlet wire of the protected load circuit. Because lightning filtering is achieved by the non-linear voltage limiting element instead of the existing capacitor of a LC filter, relative to the capacitor, the filtering effect of the non-linear voltage limiting element is not influenced by its manufacturing process and parameters, and it has great application value, simple design and low cost.

A telecom circuit protection apparatus includes a housing having at least first and second temperature responsive circuit protection devices, such as a fuse and a thyristor disposed therein. A first metal lead is connected to respective first terminals of the first and second circuit protection devices and is structured and arranged such as to transfer heat freely between the second circuit protection device and the first circuit protection device. A second metal lead is connected to a second terminal of the first device and a third metal lead is connected to a second terminal of the second device. The first, second and third metal leads extend from the housing. Advantageously, the portions of the first, second and third metal leads extending from the housing have reduced cross-sections to reduce heat loss from the apparatus and are formed and made solderable for use as connection points for surface mount connection to the apparatus. To protect multiple service lines, a circuit protector is provided for each of them. In this case, the multiple circuit protectors may advantageously be collocated in a common housing having either a common or separate ground terminal(s).

The invention relates to a control circuit which serves for security-critical control of a consumer with an inductive load portion, to be connected to a direct voltage source, and a method for failure control. It is in this case assumed that the control circuit has a power driving assembly, a free-wheeling assembly and a reverse-connection protected assembly. In order to increase the probability of failure recognition, this control circuit is extended by a method for failure control. For this purpose the semiconductor switches of the assemblies, each formed by a MOSFET, are individually driven. The different switching statuses are checked by a diagnostic device which processes voltage values to be read out at outputs of the control circuit. In this way failure-free functionality and also possible causes of failure in the control circuit can be diagnosed.

The invention relates to a bidirectional H-bridge IGBT solid-state circuit breaker with high overcurrent capacity. The bidirectional H-bridge IGBT solid-state circuit breaker comprises: four diode branch circuits L1, L2, L3 and L4, wherein the diode branch circuit L1 and the diode branch circuit L2 are connected in the same conduction direction to form a branch circuit J1, the diode branch circuitL3 and the diode branch circuit L4 are connected in the same conduction direction to form a branch circuit J2, and the branch circuit J1 and the branch circuit J2 are reversely connected in parallel;and an IGBT cluster provided with a plurality of IGBT devices which are connected with one another, wherein one end of the IGBT cluster is connected to one contact between the branch J1 and the branch J2, and the other end of the IGBT cluster is connected to the other contact between the branch J1 and the branch J2. The bidirectional H-bridge IGBT solid-state circuit breaker has the advantages ofbeing high in overcurrent capacity, high in efficiency, high in current breaking capacity, few in switching elements and short in protection time, and can achieve microsecond-level reliable turn-offwithin 100 microseconds.

The invention relates to the technical field of power protection and discloses an overvoltage control terminal and a distributed management system and method based on equal potential. The overvoltagecontrol terminal comprises an overvoltage control module, a discharge monitoring module, a fatigue monitoring module, a self-disengagement module, and a communication module. The overvoltage control terminal realizes voltage monitoring and management. The overvoltage control terminal distributed arrangement based on equal potential realizes the overall control and protection of the power supply and consumption equipment under the equal potential of a power supply network. The management system realizes visualized and centralized monitoring and management of the overvoltage control terminal ofthe entire power supply and consumption network, and has a high practical value and broad application prospects.

The invention discloses a bidirectional electrostatic discharge protection device. The bidirectional electrostatic discharge protection device comprises a first transient voltage suppressor chip, a second transient voltage suppressor chip, a first conductive wire and a second conductive wire, the first transient voltage suppressor chip comprises a first diode and a first bipolar junction transistor, and the first diode and the first bipolar junction transistor are electrically connected with the first pin. The second transient voltage suppressor chip comprises a second diode and a second bipolar junction transistor. The second diode and the second bipolar junction transistor are electrically connected with the second pin. The first conductive wire is electrically connected between the first diode and the second bipolar junction transistor, and the second conductive wire is electrically connected between the second diode and the first bipolar junction transistor.

The invention discloses a strong current pulse protection circuit which comprises an electromagnetic pulse source, a transient open circuit and a protected circuit. The input ends and the output ends of the transient circuit break circuit and the protected circuit are respectively connected with the positive electrode and the negative electrode of the electromagnetic pulse source; the transient circuit break circuit comprises a current monitoring module which outputs a first reference voltage to a control module when a current input by an electromagnetic pulse source is greater than a preset threshold current; the voltage monitoring module outputs a second reference voltage to the control module when the voltage input by the electromagnetic pulse source is greater than a preset threshold voltage; and the control module is used for disconnecting the electromagnetic pulse source from the protected circuit when receiving the first reference voltage or the second reference voltage, and driving the protected circuit by the reference voltage. According to the invention, under the strong electromagnetic pulse effect of the electromagnetic pulse source, the current passing through the protected circuit does not exceed the threshold current, the input voltage of the protected circuit does not exceed the threshold voltage, and the performance of each component can still be kept stable.

The invention discloses a current limiting circuit and electric equipment with the current limiting circuit, and the current limiting circuit comprises a current input end, a mirror image circuit and an adjusting circuit which are sequentially connected. The mirror image circuit comprises a first field effect transistor and a second field effect transistor of which grids are connected with each other; the input side of the adjusting circuit is connected with the source electrode of the second field-effect transistor and reference voltage, the output side of the adjusting circuit is connected with the grid electrode of the first field-effect transistor, and the adjusting circuit is configured to control the level of the grid electrode of the first field-effect transistor according to the output of the source electrode of the second field-effect transistor and the reference voltage; the current limiting circuit further comprises a compensation circuit, the compensation circuit is connected with the grid electrode of the second field effect transistor and is configured to output compensation voltage, and the value of the compensation voltage is equal to the value of the reference voltage. According to the current limiting circuit provided by the invention, errors in the current limiting process can be controlled, and the technical effects of cost, structure and general applicability of current limiting are achieved.

An apparatus and method for circuit interruption, with auto-power on and fault memory. The interrupter includes first and second locks in series with one another, and in series between the circuit driving source and load. The first lock is in communication with the circuit driving source. Control circuitry may be disposed between the circuit driving source and the first lock. When either lock is open the circuit is open; with both locks closed the circuit is closed. Actuating one lock does not change the state of the other lock. While closing input such as a power signal is applied to the first lock it is closed, and while the closing input is not applied it is open. When an opening input such as a fault signal is applied the second lock opens, and when a closing input such as a reset signal is applied the second lock closes.

The invention discloses a power supply detection circuit and a robot. The power supply detection circuit comprises a first unidirectional conduction element, a second unidirectional conduction element, a third unidirectional conduction element, a fourth unidirectional conduction element, a fifth unidirectional conduction element, a sixth unidirectional conduction element, an optocoupler isolationcircuit, a first switching circuit, a second switching circuit, a third switching circuit and a control circuit. A voltage of an A phase and a B phase, the voltage of the B phase and a C phase and thevoltage of the C phase and the A phase are unidirectionally conducted through the unidirectional conduction element. The corresponding switching circuit is connected with every two phases of three phase voltages according to a forward A-phase voltage, a forward B-phase voltage and a forward C-phase voltage. The optocoupler isolation circuit generates a pulse width modulation signal according to conduction of the switching circuit, the control circuit obtains a frequency parameter of a power supply according to the pulse width modulation signal so as to realize detection of power supply phaseloss and power supply power failure, an application environment range is wide, the circuit structure is simple, cost is low, detection precision and reliability are high, and practicability is high too.