35results about How to "Avoid reverse current" patented technology

The invention provides a voltage regulator which can prevent reverse current from an output terminal (122) with low current consumption regardless of the voltage of a VDD terminal (121). Low current consumption can be realized through a circuit structured in such a manner that no resistor voltage divider is used in a comparison circuit which compares the voltage of the VDD terminal (121) of the voltage regulator with the voltage of the output terminal (122).

The direction of flow of purged fuel reactant gas (20) is sensed (38, 39, 44, 53, 54) to ensure it flows outwardly from a fuel cell stack (9) towards the ambient (21). If the purged fuel reactant. gas is not flowing outwardly, a signal (39) causes a controller (26) to open the circuit (35) thereby disconnecting the electrical load (33) from the fuel cell stack.

Known junction boxes set the alignment of the external connection cables of the photovoltaic module, which are rigidly connected with a box lid. In the junction box (01) according to the invention, the box lid (04) can be placed on the box receptacle (03) in two or more different fitting positions, wherein a positive contact (05) and a negative contact (08) in the box receptacle (03) are provided for each fitting position. A positive mating contact (23) and a negative mating contact (24) are arranged in the box lid (04). According to the invention, the contacts (05, 08) and mating contacts (23, 24) are situated in such a way that, in each fitting position of the box lid (04) on the box receptacle (03), the positive mating contact (23) can be electrically contacted with one of the positive contacts (05), and the negative mating contact (24) can be electrically contacted with one of the negative contacts (08). According to the invention, the final fitting position of the box lid (04) on the box receptacle (03) is selected based on a prescribed alignment of the connection cables (30, 32) relative to the photovoltaic module (02). The invention makes it possible to preassemble junction boxes (01) and adjust them to each photovoltaic module (02) by selecting the fitting position, and hence alignment of the connection cables (30, 32).

The invention relates to the field of battery energy storage conversion power supply, in particular to a device and a method for improving charging and discharging performance of a power battery pack.In order to solve the technical problem, the controlled battery pack device is provided, a charging input/discharging output electric type controlled unit is connected in series in a battery pack toform an electric type controlled charging and discharging battery pack; the electric type controlled charging and discharging battery pack is limited in the charging and discharging electric type parameters, namely the basic electrical parameters are controlled, charging input/discharging output voltage works within an effective preset range, and the charging input/discharging output current within an effective preset range is limited. The device and the method have the beneficial effects that the power battery pack is in a straight-through charging and discharging state within a protection limit, volt-ampere impedance electrical parameters are in an uncontrolled and unadjustable free state, and intelligent internal control modular operation cannot be achieved are overcome.

The invention provides an electronic system. The electronic system comprises a display device and a data processing device, wherein the display device is connected with the data processing device and is provided with an antenna and a metal framework; the data processing device is provided with a coaxial cable extending to the display device; the coaxial cable is coupled with the antenna and feeds a signal in the antenna from the data processing device; and a part of a metal shielding layer of the coaxial cable is stripped and exposed and electrically connected with the metal framework to inhibit reverse current so as to improve the radiation efficiency of the antenna. When the electronic system is implemented, the metal shielding layer and the metal framework are electrically connected through a conductive adhesive tape or in a welding mode.

A switching circuit with the circuit protection function comprises a current-limiting resistor R1, a photoelectric coupler, a resistor R2, a resistor R3, a triode, a diode and a relay. One end of the current-limiting resistor R1 is connected with input signals and the other end of the current-limiting resistor R1 is connected with one input end of the photoelectric coupler. One input end of the photoelectric coupler is connected with the current-limiting resistor R1, the other input end of the photoelectric coupler is grounded, one output end of the photoelectric coupler is connected with a power source Vcc through the resistor R2, and the other output end of the photoelectric coupler is connected with the base electrode of the triode. The collector electrode of the triode is connected with the positive electrode of the diode, the emitting electrode of the triode is grounded, and the resistor R3 is further connected between the base electrode and the emitting electrode of the triode. The negative electrode of the diode is connected with the power source Vcc and a coil J of the relay is connected with the diode in parallel. The triode is adopted for controlling the relay to achieve the switching function, the reverse current is prevented through the photoelectric coupler, the circuit is protected, the switching circuit with the circuit protection function is obtained through less devices, and the circuit is easy to obtain and low in cost.

The invention provides a converter which comprises a plurality of parallel half-bridges. Each half-bridge comprises a first MOS transistor, a second MOS transistor and a first inductor. The gate electrode of the first MOS transistor is connected with a first control signal. The gate electrode of the second MOS transistor is connected with a second control signal. The first control signal is complementary with the second control signal for reducing cost. Alternatively, when the average current which flows over the first inductor in one period is larger than critical switching current, the firstcontrol signal and the second control signal are complementary signals. When the average current which flows over the first inductor in one period is smaller than the critical switching current, thefirst control signal and the second control signal are independent signals. Hereon, the duty ratio of the first control signal is determined by the required load voltage, and the duty ratio of the second control signal is determined by the required load voltage, the input voltage and the duty ratio of the first control signal. The converter has advantages of reducing cost, preventing reverse current in light load and improving efficiency.

The invention relates to the technical field of switch time sequence control, in particular to a switch control method and a digital controller, wherein the switch control method is used for a totem pole bridge-free circuit. The switch control method comprises the following steps of obtaining the power supply voltage of a power supply, the load voltage of a load unit and the inductive current of an inductor; respectively calculating the duty ratio M of a main switch tube and a duty ratio N of a synchronous rectifier switching tube according to the power supply voltage, the load voltage and the inductive current; if the sum of M and N is smaller than 1, switching off the synchronous rectifier switching tube. Therefore the reverse current occurring during the light load of the inductive current or the reverse current in a state in a region near the zero-passing point of the net side voltage can be inhibited.

The present invention discloses enabling readily determining which circuit, among a plurality of circuits including an optical source lighting circuit and a power supply circuit, has a failure and repairing the circuits easily in a short period. A liquid crystal television 100 comprising a power supply circuit 24 that produces and outputs various power supply voltages from an inputted commercial AC power supply, a microcomputer 22 that outputs a control signal to a plurality of circuits, respectively, including at least the power supply circuit 24 and an inverter circuit 26 that is driven by a power supply voltage output by the power supply circuit 24 to controls turning on and off of each circuit, is provided with an input terminal 53 for providing a power supply voltage from the outside of the liquid crystal television 100, and an inspection auxiliary circuit 50 connected to the power supply circuit 24 and inverter circuit 26, generating a constant voltage that starts the power supply circuit 24 and inverter circuit 26 when a power supply voltage is provided from the input terminal 53 and outputs the constant voltage as a control signal.

The invention relates to a magnetic induction transferred DC circuit breaker. The circuit breaker comprises a main current circuit and a transfer current circuit which are connected in parallel, wherein the main current circuit is used for a current in a normal working condition to pass through, and the transfer current circuit is used for transferring the current of a short-circuit fault to the main current circuit when the short-circuit fault occurs in a circuit system where the circuit breaker is located. The transfer current circuit adopts a bridge structure, a reverse current of a high-speed switch opening of the main current circuit can be avoided by controlling an action sequence of a conductive control in the transfer circuit, and the breaking capability is improved; and a mutual inductor is used for increasing a transfer speed of the short-circuit current, and bidirectional breaking of the current is achieved by a group of full-controlled power semiconductor devices.

The invention discloses a new energy electric vehicle super capacitor charging device which comprises a main control chip. The main control chip is connected with a power supply bus through an input isolation switch circuit; the input isolation switch circuit is connected with an input voltage feedback circuit; the input voltage feedback circuit is connected with an input current detection circuit; and the input current detection circuit is connected with a bidirectional BUCK-BOOST converter. The bidirectional BUCK-BOOST converter is connected with an output current detection circuit; the output current detection circuit is connected with an output voltage feedback circuit; and the output voltage feedback circuit is connected with a super capacitor through an output isolation switch circuit. The input voltage feedback circuit, the input current detection circuit, the bidirectional BUCK-BOOST converter, the output current detection circuit, the output voltage detection circuit and the output isolation switch circuit are all connected with the main control chip. A super capacitor charging circuit with a buck-boost function is formed, power optimization is carried out on a charging scheme through internal digital logic, and the functions of simplifying the circuit and reducing the cost are achieved.