32results about How to "Good constant current characteristics" patented technology

The invention relates to a high-efficiency LED constant current driving circuit. The circuit comprises an input rectification filter circuit, a switch power supply management chip, an isolation switch transformer, a primary clamping circuit of the transformer, an output rectification filter circuit, an output current sampling circuit, a reference voltage generation circuit, a comparison circuit and a photoelectrical coupling circuit, wherein the input end of the input rectification filter circuit is connected with commercial AC electricity, while the output end is connected with a primary winding of the isolation switch transformer through the switch power supply management chip; the primary clamping circuit of the transformer is connected in parallel with the primary winding of the isolation switch transformer; the input end of the output rectification filter circuit is connected with the primary winding of the isolation switch transformer, while the output end is connected with LED load; an output current sampling circuit is connected in series with the LED load; the input end of the reference voltage generation circuit is connected with the LED load; and the input end of the comparison circuit is connected with the output current sampling circuit and the reference voltage generation circuit, while the output end is connected with the switch power supply management chip through the photoelectrical coupling circuit. The circuit improves the circuit integration degree, the reliability, the constant current precision and the circuit conversion efficiency.

The invention provides a DC small current constant-current source and a method for adjusting the constant-current source and aims at solving the problem of the noise of the output current caused by the noise of an amplifier in a feedback circuit of the existing DC small current source. The DC small current constant-current source comprises a voltage source, a differential amplification circuit, a V/I conversion circuit, a current output terminal and a feedback circuit; the voltage source is connected in series with the differential amplification circuit and outputs voltage to the differential amplification circuit; the differential amplification circuit is connected in series with the V/I conversion circuit; the V/I conversion circuit generates the current and outputs the current by the current output terminal; the feedback circuit comprises a sampling circuit and a filter circuit which are connected in series; after sampling at the output current terminal of the V/I conversion circuit, the sampling circuit outputs the voltage signal which is fed back and filtrated by the filter circuit to the input terminal of the differential amplification circuit. Meanwhile, the output voltage of a feedback branch is taken as the following output voltage of the current output terminal. The invention can provide the DC small current with high precision.

The invention relates to an inductive energy-storage microsecond-grade high-power pulse current source comprising an inductive charging circuit, an inductive discharging circuit and a clamping circuit, wherein the inductive charging circuit is a series loop which consists of an excitation power supply V2, an inductor L and a switch tube; the inductive discharging circuit is a series loop which consists of a loader, a fly-wheel diode D1 and the inductor L; and the clamping circuit is connected with the inductive charging circuit in a spanning way. The invention can generate a current-controllable high-power pulse power supply on the negative-resistance loader, has adjustable striking voltage, not only has very well constant-current characteristics, but also can fast respond to plasma arcs and realize the ultrafast switching of striking arcs and constant currents.

The invention provides a low-power-consumption and low-delay current comparator based on Wilson current sources, and a circuit module. The low-power-consumption and low-delay current comparator basedon the Wilson current sources comprises a first Wilson current source and a second Wilson current source serving as an input stage, a differential amplifier serving as an intermediate stage, and an output gain stage serving as an output stage, wherein a first input current and a second input current, which serve as comparison objects, are respectively input into the first Wilson current source anda second Wilson current source; an output end of the first Wilson current source and an output end of the second Wilson current source are respectively connected to two input ends of the differentialamplifier; and an output end of the differential amplifier is connected to the output gain stage. A current structure provided by the invention has the advantages of high comparison precision and a low-delay propagation characteristic.

The invention relates to an infrared gesture recognition device and a recognition method. The infrared gesture recognition device comprises an infrared receiving tube, an infrared compensation tube, adriving module, a control module and a plurality of infrared emission tubes which are integrated on a PCB, wherein the infrared receiving tube, the infrared emission tubes and the infrared compensation tube are respectively arranged on the back of the PCB; open holes are formed in positions corresponding to the infrared receiving tube and the infrared emission tubes on the PCB and are used for emitting and receiving infrared ray from the front of the PCB; the infrared compensation tube is used for emitting infrared ray into the PCB. Compared with the prior art, infrared emission units and aninfrared compensation unit of the device adopt proportional circuits based on mirror current sources, so that the current in the device has certain self-regulation capability and good constant-currentcharacteristic, and the device has high temperature stability; meanwhile, compared with the prior art, the device is capable of removing the interference of the background environment light and solves the disadvantage that the infrared gesture module is influenced by the environment light at present; the reliability and the stability are improved.

The invention relates to a multipath current-sharing output LED (Light-Emitting Diode) driving power supply and a dimming method. The driving power supply comprises a switching network module, an LCL-nT type resonance network, a rectification network and a load unit, which are orderly connected with each other; the switching network comprises a first bridge arm and a second bridge arm which are connected in parallel, wherein the second bridge arm is used as a phase shift bridge arm and used for realizing wide-range lighting control; and the load unit comprises n paths of current-sharing output LED loads. The multipath current-sharing output LED driving power supply and the dimming method provided by the invention can realize constant and balanced output current under multiple paths of different LED lamp voltages, and have the characteristics of being simple in circuit structure, good in constant-current characteristic and high in current sharing accuracy, etc.

The invention discloses an LED drive device and a control circuit and a control method of the LED drive device. The control circuit of the LED drive device comprises a conduction time control circuit, an average current value obtaining circuit, a proportion superposition circuit, a comparison circuit, an OR gate, a set signal generation circuit and an RS trigger, wherein the conduction time control circuit is used for generating a first control signal according to a sawtooth wave signal and first reference voltage; the average current value obtaining circuit is used for generating an average current signal of reflecting an average output current value according to a current sampling signal; the proportion superposition circuit is used for superposing the average current signal and the sawtooth wave signal according to the ratio to generate a superposed signal; the comparison circuit is used for comparing the superposed signal with second reference voltage to generate a second control signal; the OR gate is used for generating a set signal according to the first control signal and the second control signal; the set signal generation circuit is used for generating the set signal; and the RS trigger is used for generating a switching control signal according to a reset signal and the set signal. By the control circuit of the LED drive device, a compensation network of a regulating ring can be omitted; a relatively high power factor is achieved; and a leakage circuit is not needed when applied to dimming of a silicon controlled rectifier.

The invention discloses a constant-current driven LED projection lamp which comprises a bottom shell, a surface cover, an LED light source assembly and an LED driver, wherein the LED light source assembly is mounted in a light source mounting slot; the LED driver is mounted in a drive mounting slot; the LED driver and the LED light source assembly are independently mounted relative to each other, so that the LED driver is conveniently replaced and maintained; and a primary side feedback type LED constant-current drive circuit is arranged in the LED driver, and the circuit is simple and can output constant current. The LED light source assembly comprises an SMD light source and a light reflector; a plurality of light reflecting cups which are in one-to-one correspondence to LED chips are arranged on the light reflector; and each light reflecting cup independently distributes light for each LED chip. The constant-current driven LED projection lamp improves light outlet efficiency, so that light spots are more uniform.

The invention relates to an adjustable constant current source integrated chip and a manufacturing method. The adjustable constant current source integrated chip comprises a monocrystalline silicon N-type polished wafer which serves as an N-doped region, an N+ heavily doped region is arranged on the back of the N-doped region, a triode Q2, a current regulative diode (CRD), a triode Q1 and a resistor R are arranged on the front of the N-doped region, one end of an N+ doped region of the resistor R is connected with an N+ doped region of the triode Q2, meanwhile, the N+ doped region of the resistor R serves as the cathode of the constant current source integrated chip, the other end of the N+ doped region of the resistor R is respectively connected with an N+ doped region of the triode Q1 and a P doped region of the triode Q2, a P doped region of the triode Q1 is respectively connected with a P doped region of the CRD, the P doped region of the triode Q2 and an N doped region of the triode Q2, an N doped region of the CRD is respectively connected with the P doped region and a second N+ doped region of the CRD, and the N+ heavily doped region serves as the anode of the constant current source integrated chip.

The invention provides an SOI lateral constant-current diode and a manufacturing method thereof, and belongs to the technical field of semiconductor power devices. The lateral constant current diode is formed by connecting a plurality of cell interdigitals with the same structure; the cell comprises a substrate, a buried oxide layer, first conductive type lightly doped silicon, a second conductivetype diffusion well region, a first conductive type channel injection region, a second conductive type heavily doped region, a first heavily doped region, a second heavily doped region, an oxidationmedium layer, a metal anode and a metal cathode, wherein the first heavily doped region and the second heavily doped region are of the first conductivity type. The constant-current diode adopts the SOI technology, and adverse effects caused by substrate leakage current in an integrated system can be effectively prevented.

The invention relates to electronic techniques, and provides a constant-current drive circuit of an LED switching power supply. The constant-current drive circuit comprises a rectification filter circuit, a power tube, an RS flip-flop, an oscillator and an operational amplifier. Two input ends of the RS flip-flop are respectively connected with an output end of the operational amplifier and the oscillator, and a Q end of the RS flip-flop is connected with a grid of the power tube. The constant-current drive circuit of the LED switching power supply is characterized in that the operational amplifier is connected with the input ends of the RS flip-flop through a delay doubling circuit. The constant-current drive circuit of the LED switching power supply has the advantages that the delay doubling circuit is added in a loop circuit compared with an existing BUCK structured constant-current drive circuit, and enables output current to be unrelated to LED voltage, clock periods and intensity of inductance, and therefore the constant-current drive circuit is good in constant-current characteristic.

The invention discloses a collector for vibration monitoring of a shield tunneling machine, which comprises a communication module, wherein the communication module comprises an RS455 communication circuit, the RS455 communication circuit comprises a bidirectional voltage stabilizing diode DZ1, a bidirectional voltage stabilizing diode DZ2, a bidirectional voltage stabilizing diode DZ3, a resistor R48, a resistor R49, a resistor R52, a resistor R54, a resistor R56, a resistor R59, a resistor R58, a resistor R55, a capacitor C79 and a chip U19, the model of the chip U19 is ADM2486, a second pin of the chip U19, an eighth pin of the chip U19 and the other end of the resistor R55 are all grounded GND; and one end of the capacitor C79, one end of the resistor R49 and the sixteenth pin of the chip U19 are connected with a power supply VCC-S5V2. The collector has the advantages that interference in the collection process is avoided, and the final analysis result is accurate.