43results about How to "Current limit" patented technology

The present invention relates to a power semiconductor device for an igniter, which protect a semiconductor switch member in the overheat state and avoid the error ignition occurring at an inappropriate time followed by the current shut off. A power semiconductor device 5 for an igniter comprises: a semiconductor switching device 4 causing a current to flow through a primary side of an ignition coil 6 or shutting off the current flowing through the primary side of the ignition coil; an integrated circuit 3 driving and controlling the semiconductor switching device; and a temperature sensing element 43 sensing temperature of the semiconductor switching device 4, wherein the integrated circuit including an overheat protection circuit limiting a current through the semiconductor switching device to a value lower than a current through the semiconductor switching device 4 during normal operation, when temperature sensed by the temperature sensing element 43 is over predetermined temperature.

The invention discloses a low-noise high-frequency converter. The low-noise high-frequency converter is characterized by being composed of a transformer T1, a transformer T2, a linear driving circuit connected with the primary side of the transformer T1, a mixer circuit connected with the secondary side of the transformer T1, a first switching circuit connected with the mixer circuit, a processing circuit connected with the mixer circuit and the first switching circuit, and a second switching circuit connected with the output end of the processing circuit; the primary side of the transformer T2 is connected with the second switching circuit. The linear driving circuit is composed of a driving chip U, a triode VT4, a triode VT5, a triode VT6, a triode VT7, a polar capacitor C7 and the like, wherein the positive pole of the polar capacitor C7 serves as the circuit input end, and the negative pole of the polar capacitor C7 passes through a resistor R7 and then is connected with an IN1 pin of the driving chip U. According to the low-noise high-frequency converter, the linear driving circuit is adopted, and thus the converter is made to generate quite low noise when working under high-frequency working conditions, and is suitable for occasions requiring low noise.

For converting a first DC voltage to a second DC voltage, a first bridge circuit comprised in a power converter is controlled to convert the first DC voltage to a first AC voltage. The first AC voltage is transformed to a second and possibly further AC voltage. The second and each possibly further AC voltage is converted to a DC voltage by respective bridge circuits. To increase efficiency of the power converter switches of the power converter are controlled to operate in soft switching. Thereto a duty cycle of each AC voltage is controlled. In an embodiment, a half-cycle voltage-time integral of each AC voltage is controlled to be substantially equal.

The invention discloses a device for current limiting protection of a load or an output. The device includes a power supply module, a current limiting circuit, a reset circuit and a load. The current limiting circuit includes a field effect transistor, an inductor, and the zeroth to third resistors. Among them: the field effect transistor, the inductor, and the zeroth resistor are connected in series with the load, and the zeroth to third resistors form a feedback network with the field effect transistor. When the current exceeds the set current threshold, the resistance value of the zeroth resistor will be instantaneously changed by The low resistance value becomes high resistance value, and since the resistance value of the zeroth resistor becomes high resistance value, the feedback network formed by the zeroth to third resistor and the field effect transistor will set the gate voltage of the field effect transistor to the limit The potential of the current flow can be quickly and effectively realized to limit the current, realize the rapid response to the instantaneous large current, and effectively protect the circuit components.

The invention relates to the technical field of integrated circuits, in particular, to a voltage-controlled oscillator, an integrated chip, and an electronic device. The voltage-controlled oscillatorcomprises a resistor unit, a current mirror unit, a bias unit, and an oscillating unit. The current mirror unit responds to a first bias voltage provided by the bias unit to carries out bias processing on a voltage of a first node at a first current path and a voltage of a third node at a third current path to generate a first bias voltage and is also used for responding to resistance configuration of the resistor unit and adjusting a third current flowing through the third current path, wherein the first current flowing through the first current path is equal to the third current. Therefore,with configuration of the resistance corresponding to the resistor unit, the charging and discharging time of the capacitor of the oscillating unit can be indirectly adjusted to change the oscillationperiod of the oscillating unit and thus the changed oscillation period is closer to a desired oscillation period, so that the output accuracy of the oscillation period is improved.

The invention discloses a current measurement method and device based on single-axis magnetic sensing chips. The method comprises the steps: receiving the magnetic field intensity, measured by each single-axis magnetic sensing chip, of a to-be-measured cable at the current position, wherein the single-axis magnetic sensing chips are located in the same plane or mutually parallel planes; obtainingthe relative position of each single-axis magnetic sensing chip; and calculating the current value of the to-be-measured cable according to the relative positions of the single-axis magnetic sensing chips and the magnetic field intensity measured by the single-axis magnetic sensing chips. According to the technical scheme disclosed by the invention, non-closed-loop measurement can be realized by utilizing the single-axis magnetic sensing chips, so that the cumbersome degree of current measurement can be reduced, and the current value of a to-be-measured cable in almost any scene can be measured, so that the current measurement is not limited by the installation scene of the to-be-measured cable.