34results about How to "Enhanced overcurrent protection" patented technology

Current sensing resistors are connected directly to output terminals of MOSFETs forming the series switching stage of a PWM sinewave dimmer. An analog sensed current signal is coupled through an EMI resistant current link to comparators that provide an overcurrent indication in response to an overcurrent condition. A logic circuit overrides PWM control signals from a programmable controller, and operates drivers to render the series switching stage nonconductive and to render a clamp switching stage conductive until after the end of the current PWM duty cycle power on segment. The logic circuit sends an overcurrent signal through an optocoupler to an input of the programmable controller. The input of the controller is polled at a clock frequency for overcurrent signals and if the count exceeds a limit in any half cycle, or a maximum sum in sixteen half cycles of the AC supply, the series switching stage is rendered nonconductive and the clamp switching stage is rendered conductive pending a reset signal.

An overcurrent detection circuit that detects an overcurrent state of a transistor that outputs a current to a load is provided with a start-up monitoring portion that distinguishes between a start-up state and a steady state, an overcurrent monitoring portion that monitors an overcurrent state of the transistor, and an output voltage monitoring portion that detects whether the output voltage to the load is normal or abnormal. The overcurrent monitoring portion changes an overcurrent detection level while referring to information from the start-up monitoring portion and the overcurrent monitoring portion.

The invention relates to a DC-DC conversion circuit overcurrent protection circuit, method and display panel. The overcurrent protection circuit comprises a first comparator (OP1) for comparing a DC voltage and a DC voltage. An OCP detect voltage (V1) and a first reference voltage (Vref1) in a DC conversion circuit output a first comparison result (EN1) to a logic processor; A second comparator (OP2) for comparing the OCP detection voltage (V1) and the second reference voltage (Vref2), and outputting a second comparison result (EN2) to the logic processor; A logic processor that judges DC based on the first comparison result (EN1) and the second comparison result (EN2); DC convert that working state of the circuit and output the corresponding control signal to the OCP current limiter; OCPcurrent limiter, according to the control signal, the corresponding overcurrent protection operation is performed on the DC-DC conversion circuit. The invention not only realizes the functions of theoriginal overcurrent protection circuit and the magnitude of the current triggering the overcurrent protection, but also limits the magnitude of the output current after the overcurrent protection occurs to prevent the risk of smoke and fire caused by the large current.

A lighting circuit for a light source includes a drive circuit and an overcurrent protection circuit. The drive circuit supplies power to the light source. The overcurrent protection circuit is inserted between the drive circuit and the light source. The overcurrent protection circuit restricts a lamp current flowing into the light source so that the lamp current does not exceed an overcurrent threshold value. The overcurrent protection circuit includes a transistor, an inductor, a rectifier, a current sensor and an overcurrent protection controller. The current sensor generates a current detection signal according to the lamp current. The overcurrent protection controller controls ON / OFF of the transistor based on the current detection signal and the overcurrent threshold value. The transistor, the inductor and the rectifier are disposed in a T-shape.

The invention discloses an electric control device of an engine extinguisher. The engine extinguisher comprises a flexible shaft, a motor used for driving the flexible shaft to stretch out and retract back and a detection switch which is turned on or turned off through triggering of the stretching operation and the retraction operation of the flexible shaft. The electric control device comprises a power circuit, a main controller, a first signal processing circuit, a second signal processing circuit, a motor driving circuit and a current sampling circuit used for sampling a driving current of the motor. The input end of the first signal processing circuit is connected with the signal output end of an ignition switch. The input end of the second signal processing circuit is connected with the signal output end of the detection switch. The input end of the main controller is respectively connected with the output end of the first signal processing circuit, the output end of the second signal processing circuit and the output end of the current sampling circuit and the output end of the main controller is connected with the input end of the motor driving circuit. The invention further discloses a control method of the engine extinguisher. According to the electric control device of the engine extinguisher and the control method of the engine extinguisher, the current overcurrent protection function and the self-recovery function when the current is abnormal are achieved and in addition, a motor driving current does not flow across the detection switch.

The invention belongs to the technical field of compressor control, and provides an air conditioner compressor protection and control method and device. According to the method, when an over-current detection signal is received at a protection signal input end of an intelligent power module, whether a fault signal is output at a fault signal output end of the intelligent power module in a preset period of time or not is judged; if yes, a power source protection switch module is controlled to output power supply currents in a direct power supplying mode; otherwise, it shows that the intelligent power module is damaged, and therefore the power source protection switch module needs to be controlled to reduce the power supply currents in a current-limiting mode to a preset safety current range. Thus, on the condition that the intelligent power module is damaged, the abnormal over-current phenomenon is prevented from occurring in driving currents of an air conditioner compressor by reducing the power supply currents, a good over-current protection effect is achieved on the air conditioner compressor and the problem that in the prior art, when an intelligent power module is damaged, over-current protection of an air conditioner compressor cannot be realized is solved.

The invention discloses an overcurrent protection method and device, a storage medium and an air conditioner, and the method comprises the steps: detecting a power line of a compressor of the air conditioner through a radar with a set wavelength, and detecting the current flowing through the compressor of the air conditioner so as to obtain the current flowing through the compressor; determining whether the current flowing through the compressor is greater than a set overcurrent protection value or not; if the current flowing through the compressor is greater than the set overcurrent protection value, determining that an overcurrent phenomenon occurs in the current flowing through the compressor, and generating an overcurrent protection instruction; and starting a set overcurrent protection mechanism according to the generated overcurrent protection instruction so as to realize overcurrent protection of the air conditioner. According to the scheme, the problem that the overcurrent protection reliability is poor due to the fact that a current transformer needs to be adopted for detecting the current flowing through the compressor in the overcurrent protection of the air conditionercan be solved, and the effect of improving the overcurrent protection reliability is achieved.

An apparatus comprises a switch, a current monitor, and a controller. During operation, the switch controls an amount of current through the load. The current monitor samples a magnitude of the current through the load, a magnitude of which varies over time during a time duration. Based on integrating the sample magnitudes of the current through the load over the time duration, the current monitor produces a current sense value. The current sense value is representative of an amount of current through the load. The controller controls an operational state of the switch based upon a comparison of the current sense value with respect to an over-current threshold value. For example, in response to detecting a condition in which the current sense value is greater than the overcurrent threshold value, the controller turns OFF (deactivates) the switch, reducing or eliminating delivery of current through the load.

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 discloses an LED drive circuit and method based on voltage memory and segmented current limiting. The circuit comprises a rectifying circuit, a voltage division circuit, a voltage increasing and reducing detection module, a voltage memory module, a comparator set, a control logic module, a high-voltage switch circuit, a detection resistor, a current detection comparator and an LED lamp string. According to the drive method of the circuit, according to the increasing and reducing characteristics of the directly-rectified direct-current ripple voltages, the segmented type lightening control mode is adopted in the load of the LED lamp string. The drive circuit solves the problem of the influence of the difference of voltage current characteristics of an LED chip adopted by the lamp string in the actual application on drive currents, the work current of the LED lamp string in the whole work period is limited within the designed largest current value Imax, the problems of lower brightness caused by undercurrents and damage, caused by overcurrents, to the LED chip are solved, the light-emitting efficiency of the LED lamp is improved, and meanwhile overcurrent protection can be carried out on an LED device well.

The invention discloses a battery management system with a charging high-voltage interlocking function. The battery management system comprises a power battery pack, a high-voltage power interlockingmodule and a battery management module. A switch port of the power battery pack is connected with the battery management module. The output end of the battery management module is connected with the high-voltage power interlocking module through a wireless transceiver. The output end of the high-voltage power interlocking module is connected with a controllable high-voltage direct current contactor. The drive end of a motor controller is connected with a motor. The battery management module comprises a master controller and a CAN bus communication interface. The signal end of the master controller is connected with the wireless transceiver through the CAN bus communication interface. The system monitors a high-voltage loop of a battery electric vehicle in real time, and various types of feedback information is provided through a human-computer interaction interface, so that the high-voltage loop is effectively controlled in the starting and stopping processes of the battery pack and analarm is given in time when the high-voltage loop breaks down.