35results about How to "Extended off time" patented technology

The invention provides a switching control circuit, a switching circuit and a constant switching-on time control method. When switching-on time of a main pipe reaches constant switching-on time, whether inductive current reaches instruction current or not is detected; if the inductive current does not reach the instruction current, the switching-on time of the main pipe is prolonged; the main pipe is switched off and an auxiliary pipe is switched on after the inductive current reaches the instruction current or exceeds the instruction current by a certain threshold value; when the main pipe is switched off and the auxiliary pipe is switched on, whether the instruction current is lower than the instruction current or not is detected in real time; and if the auxiliary pipe is switched off, the main pipe is switched on again. The switching control circuit, the switching circuit and the constant switching-on time control method, provided by the invention, aim at realizing stable-voltage control of output voltage, so that the voltage conversion with a relatively large duty cycle is realized.

The invention provides an insulated gate bipolar transistor (IGBT) protection circuit and a motor control system, belonging to the filed of the motor control. The IGBT protection circuit comprises a sampling circuit, a feeding back circuit, a driving circuit and a slow turn-off circuit. The IGBT protection circuit adopts the slow turn-off circuit, thus the turn-off time of the IGBT is prolonged, the current change rate is reduced and the IGBT is protected against damage when the IGBT carries out the over-current protection.

The present invention provides an oscillator start-up control circuit capable of shortening the start-up time, stably controlling the start-up time, and stabilizing the oscillation frequency after the start-up of the oscillation circuit. The oscillation circuit (1) is as follows: the input and output of the inverter (14) are connected to the two ends of the crystal oscillator (15) and the two ends of the resistor (16), and the input is connected to the MOS variable capacitor (10) Drain, connect the output to the drain of the MOS variable capacitor (11), connect the source of the MOS variable capacitor (10) to the fixed capacitor (12), connect the source of the MOS variable capacitor (11) to Fixed capacitor (13), connect the other end of the fixed capacitor (12, 13) to GND. Furthermore, the resistor (18) and the switch (7) are connected to the gate of the MOS variable capacitor (10), the resistor (19) and the switch (8) are connected to the gate of the MOS variable capacitor (11), and the resistor (18) is connected to the gate of the MOS variable capacitor (11). , 19) the other ends are connected to each other, and then connected to the voltage control circuit (3).

The invention discloses a biochemical analyzer conveying system which comprises sample-injection tracks, forward tracks, recovery tracks, to-be-measured sub-tracks, emergency sub-tracks and return sub-tracks; the sample-injection tracks, the forward tracks and the recovery tracks are arranged in parallel to each other, wherein at least one of the to-be-measured sub-tracks, the emergency sub-tracks and the return sub-tracks are arranged. The to-be-measured sub-tracks, the emergency sub-tracks and the return sub-tracks are arranged between the sample-injection tracks and the forward tracks. The to-be-measured sub-tracks, the emergency sub-tracks and the return sub-tracks are perpendicular to the sample-injection tracks and the forward tracks. The track conveying system can be set horizontally in the biochemical analyzer, which can realize butt-joint with the longitudinal tracks in the biochemical analyzer. The buffer amount of the sample rack can be greatly increased on the premise of not increasing the length of the biochemical analyzer.

The invention discloses a switched capacitor type high-bandwidth envelope tracking power supply circuit which comprises a step wave voltage generating circuit and an A-class linear amplifier. The stepwave voltage generating circuit is in cascaded connection with the A-class linear amplifier. The output of the step wave voltage generating circuit is used as input of the A-class linear amplifier. The step wave voltage generating circuit is obtained through serially connecting n switched capacitor circuits with the same structure. (1 / n):1 frequency reduction of the switching frequency of the switch tube in each switched capacitor circuit relative to the frequency of a tracking signal can be realized. Furthermore the on time or off time of a switch tube is effectively prolonged, thereby realizing sufficient switching-on or switching-off, and improving working performance and reliability in a high-bandwidth tracking condition. Compared with a traditional method, the switched capacitor typehigh-bandwidth envelope tracking power supply circuit has advantages of greatly reducing number of power supplies, reducing complexity degree and cost of the circuit, and improving system efficiency.

The present invention relates to a LED drive circuit with an adjustable current. Electric supply is subjected to voltage reduction by a transformer and then is output to a rectification filtering unit, the rectification filtering unit outputs the electric supply to a LED lamp set for power supply, a negative pole of the LED lamp set is connected with an MOS tube Q4, a sampling resistor R6 and a feedback comparison unit in order to achieve constant current of a LED drive circuit, the feedback comparison unit outputs a current to a PWM generation unit, the PWM generation unit outputs PWM waveform signals to a drive unit, the drive unit improves the switching motion response speed for drive of the MOS tube Q4, a controller in the PWM generation unit performs processing of the external currentadjusting command from a serial port, the frequency of outputting PWM signals by the PWM generation unit is regulated to achieve adjustment of the size of a current of the LED lamp set. The LED drivecircuit with an adjustable current can achieve regulation in a range from none to a set maximum value, the provided drive unit circuit can effectively accelerate the on-off time of the MOS tube and can eliminate the peak and the burr of the gate waveform of the MOS tube so as to greatly improve the efficiency and the stability of the LED drive circuit.

The invention provides an insulated gate bipolar transistor. The insulated gate bipolar transistor comprises a first base region, a second base region, an emitter region, a gate oxide layer, a buffer region, a first collector electrode area, a second collector electrode area and a third collector electrode area. The second base region, the emitter region and the gate oxide layer are sequentially arranged on one side of the first base region, and the buffer region, the first collector electrode area, the second collector electrode area and the third collector electrode area are sequentially arranged on the other side of the first base region. The conduction type of the second base region, the conduction type of the first collector electrode area and the conduction type of the second collector electrode area are opposite to the conduction type of the first base region. The conduction type of the emitter region, the conduction type of the buffer region and the conduction type of the third collector electrode area are the same as the conduction type of the first base region. The maximum thickness of the third collector electrode area is equal to the maximum thickness of the second collector electrode area, and the dosage concentration of the buffer region, the dosage concentration of the first collector electrode area and the dosage concentration of the third collector electrode area are gradually increased, so that a bipolar transistor structure is formed.

The invention discloses a sample recycling system of a biochemical analyzer. The sample recycling system comprises a bracket, wherein the bracket is provided with a returning conveying region and a bridging avoiding region which are connected with each other; the returning conveying region is provided with a returning conveying assembly; the bridging avoiding region is provided with a bridging avoiding assembly; the returning conveying assembly comprises a conveying rail and a returning conveying frame; the returning conveying frame is driven through a first transmission mechanism to do reciprocating motion between the returning conveying region and the bridging avoiding region; the returning conveying frame is used for conveying a sample frame between the returning conveying region and the bridging avoiding region. The sample recycling system can be used for transferring a sample in a buffering region into a testing rail or a sample recycling rail, so that the feeding amount of the sample frame of the biochemical analyzer can be enlarged and the off-line time of testers is prolonged.

The invention provides a system for providing working frequency for a switching power supply converter. The system comprises a feedback input circuit, a variable frequency and intermittent mode control circuit, a logical control circuit, an oscillator and a PWM (Pulse Width Modulation) generator, wherein the feedback input circuit is used for feeding a load state back into an integrated circuit through an optical coupling device and generating a first control signal; the variable frequency and intermittent mode control circuit is configured to receive the first control signal and generate a first output signal related to the frequency; the logical control circuit is configured to receive the first output signal and a sawtooth wave signal of the oscillator to form a second output signal; the oscillator is configured to receive the second output signal to control the charging and the discharging of a capacitor through current to form a third output signal (a sawtooth wave signal); and the PWM generator is configured to receive the second output signal and the third output signal to form a fourth output signal for switching on or off a power switch of the switching mode power supply converter. Through the system, the working frequency of a switching power supply is controlled to change along with the change of a load, so that the aim of reducing power consumption is achieved, and the efficiency of the system is increased.

The invention discloses a transformer anti-saturation control system for a flyback switching power supply. The transformer anti-saturation control system comprises an oscillator used for outputting an open signal to open a power tube when the flyback switching power supply works; a peak value comparator used for transmitting a delay signal to a delay circuit when the sampling voltage of a CS sampling resistor is greater than a first voltage threshold; the delay circuit used for transmitting a detection signal to a saturation detection circuit according to the delay signal after delaying the scheduled time; an analog adder used for superposing the first voltage threshold and the preset superimposed voltage, and obtaining a second threshold voltage; the saturation detection circuit used for detecting the sampling voltage and the second threshold voltage when receiving the detection signal, and transmitting a first control signal to the oscillator when the sampling voltage is greater than the second threshold voltage; and the oscillator is further used for reducing the frequency of the open signal when receiving the first control signal, so as to prolong the turn-off time of the power tube. The transformer anti-saturation control system for the flyback switching power supply provided by the invention can reset a transformer in time when the transformer is in a saturation state.

The invention discloses a hybrid integrated IGBT (insulated gate bipolar translator) drive circuit and belongs to the technical field of drive of a power device. The circuit comprises a hybrid integrated IGBT drive chip and a voltage stabilizing tube; the hybrid integrated IGBT drive chip selects QP12W05S-37(A); the voltage stabilizing tube selects DZ402 and DZ403; the voltage stabilizing tube is connected with the hybrid integrated IGBT drive chip; an external signal is input to the hybrid integrated drive chip after being limited by a resistor; the hybrid integrated drive chip outputs stable voltage signal to drive on / off of the IGBT; the circuit has the function of outputting the signal and limiting the amplitude, so that the signal received by the grid of the IGBT is within a safe range, and current at two ends of the IGBT is detected at the same time. The drive circuit locks, outputs and emits an error signal to ensure the safety of the IGBT when the current value exceeds a limit value. The hybrid integrated IGBT drive circuit has the advantages that the drive circuit has a power supply, and has the functions of blocking and restoring a fault, and adjusting protective soft turn-off time.

The invention provides a brushless direct current motor noise suppression driving method, and the method comprises the following steps: establishing a model, and obtaining the turn-off time of a delayed turn-off phase during commutation and the turn-on time of a delayed turn-on phase during commutation; judging whether the motor is in high-speed operation or low-speed operation; during high-speed operation, delaying the turn-off time of the turn-off phase during commutation; and during low-speed operation, delaying the on-time of the on-phase during commutation. According to the driving method for noise suppression of the brushless direct current motor, the turn-off time of the turn-off phase or the turn-on time of the turn-on direction during phase commutation is delayed by judging whether the motor is in high-speed operation or low-speed operation, the torque ripple during phase commutation is reduced, and finally the noise of the motor is reduced.

The invention discloses a high-broadband envelope line tracking power supply and a control method therefor. The power supply comprises a step wave voltage generation circuit, a control circuit and an A type linear amplifier, wherein the step wave voltage generation circuit consists of n series units connected in series; each series unit consists of m voltage generation circuit units connected in series; according to the method, n groups of m fitted pulse signals within a changing period are selected based on timing sequence; the rising edges of the m fitted pulse signals in any one group are allocated to one group of control signals independently, namely the rising edges are used as the rising edges of the group of control signals; the falling edges of the m fitted pulse signals in any one group are allocated to one group of control signals independently, namely the falling edges are used as the falling edges of the group of control signals; and the switch-on and switch-off time of a switching tube can be effectively expanded in a high-broadband envelope line tracking condition to ensure full switch-on and full switch-off, so as to improve the switching performance and the working reliability of the switching tube in the high-frequency operation and to realize actual high-broadband envelope line tracking.

The invention discloses an IGBT (Insulated Gate Bipolar Translator) power device applied at low power and a manufacturing method thereof. The method comprises the following steps: performing semiconductor impurity injection or diffusion operation on the front side of a silicon substrate; performing corroding treatment on the front side which is subjected to the semiconductor impurity injection or diffusion operation; performing P type ion injection on the back side of the silicon substrate to form a P region; forming a groove on the back side of the silicon substrate; performing N type ion injection on the surface of the groove to form an N region; performing diffusion operation on the P region and the N region; performing an outer layer encapsulating treatment on the silicon substrate. The method has the advantages that by means of groove formation, P type ion injection and N type ion injection on the surface of the groove under the condition of not influencing the voltage endurance capability of the device, the switch-on / off time of a low-voltage IGBT can be prolonged respectively, extremely low startup voltage drop and rapid reverse switch-off recovery are realized.

The invention provides a switch control circuit, a switch circuit and a constant off-time control method. When the on-time of the auxiliary tube reaches the constant off-time, it is detected whether the inductor current is less than the command current; The turn-off time; until the inductor current is less than the command current or less than a certain threshold of the command current, the main tube is turned on and the auxiliary tube is turned off; when the main tube is turned on and the auxiliary tube is turned off, it is detected in real time whether the inductor current exceeds the command current. Then the auxiliary pipe is turned on, and the supervisor is turned off again. The purpose of the present invention is to provide a switch control circuit, a switch circuit and a constant off-time control method, the purpose of which is to realize the voltage stabilization control of the output voltage, thereby realizing the voltage conversion with a smaller duty cycle.

The invention discloses an electro-hydraulic emergency shutdown system for testing procedures, which is characterized by comprising: a plurality of remote control button boxes, which are connected in parallel through multi-core cables; and an electric control panel, which is connected with the plurality of remote control button boxes in parallel. A control button box is connected, and the electric control panel has a data communication interface; a solenoid valve box, which is connected with the electric control panel; an induction gas line, one end of which is connected with the solenoid valve box; a hydraulic control panel, It is connected with the other end of the induction gas line. The invention also discloses a control method for an electro-hydraulic emergency shutdown system used in a testing process. The electro-hydraulic emergency shutdown system is controlled by bus control or signal input to isolate the surface testing process from the testing wellbore, and electrical signals are used to control the electro-hydraulic emergency shutdown system. The control method shortens the response time of the shutdown system.

The invention discloses a rail conveying system for a biochemical analyzer. The rail conveying system comprises a first bracket, wherein the first bracket is provided with a conveying belt assembly and a limit baffle mechanism. The limit baffle mechanism is arranged at the sample outlet end of the conveying belt assembly; the limit baffle mechanism is used for restricting the sample rack on the sample outlet end of the conveying belt assembly; the first bracket is further provided with a pushing mechanism. The pushing mechanism is used for urging the sample rack on the sample outlet end of the conveying belt assembly away from the conveying belt assembly. The rail conveying system can be set horizontally in the biochemical analyzer to realize the butt joint with the longitudinal rail in the biochemical analyzer, so that the buffer amount of the sample rack can be greatly increased on the premise of not increasing the length of the biochemical analyzer.

The invention relates to a circuit structure for realizing a stepless dimming function, and the circuit structure comprises: a first current generation circuit module which is used for achieving the continuous linear change output of a first current; a second current generation circuit module which is used for realizing continuous linear change output of second current; a first switch module which is used for controlling the charging and discharging time of the capacitor; a second switch module which is used for controlling the charging and discharging time of the capacitor; a frequency modulation module which is used for performing frequency modulation on the first current and the second current; and a LED driving module which is used for dimming the LED light source. By the adoption of the circuit structure for achieving the stepless dimming function, a dimming circuit based on a PFM mode and an implementation mode are provided, the working frequency of the circuit is modulated, the switch-off time of a switch tube is increased to change the duty ratio of the switch-on time of the switch tube, and finally LED dimming is achieved; and the LED output current can change linearly along with the dimming control signal, and a stepless dimming scheme can be realized.

The invention discloses an LED silicon-controlled rectifier phase-controlled dimmer and a stroboflash eliminating method and a stroboflash eliminating circuit thereof. The circuit comprises a rectifier module and a stroboflash control module. The stroboflash control module compares the phase adjustment values of two adjacent rectification periods, and extends the turn-off time of an LED lamp string in the rectification period with smaller phase adjustment value to make the turn-off time of the LED lamp string in the rectification period with smaller phase adjustment value consistent with the turn-off time of the LED lamp string in the rectification period with larger phase adjustment value. Thus, the conduction time of the LED lamp string is the same in adjacent rectification periods, and stroboflash is eliminated.

The invention discloses a trench gate type insulated gate bipolar translator (IGBT) with a double-face diffusion residual layer and a manufacturing method thereof. The IGBT comprises an N-type base region, a P-type base region, a back P+ collector region, an N+ emitter region, a P+ emitter region, a gate oxide layer, an emitter, a gate electrode and a collector. The N-type base region is composed of an N+ diffusion residual layer, an N- drift region and an N+ buffer layer, wherein the N-type diffusion residual layer, the N- drift region and the N+ buffer layer are stacked up in sequence. The P-type base region is located on the N+ diffusion residual layer. Doping concentration gradually increases outwards from a boundary of the N- drift region with the N+ diffusion residual layer and the N+ buffer layer. The manufacturing method of the IGBT is characterized in that the non-uniform doped N+ layers are formed on the front face and the back face through one-time double-face high temperature deep junction diffusion at the same time, the N+ diffusion residual layer is formed on the front face of the N- drift region, so that the ion doping concentration of the N-type front face is improved, and a conductivity modulation effect is strengthened. The N+ buffer region on the back face can reduce breakover voltage drop of a device, and the turn-off time of the device is prolonged. The manufacturing method can reduce the steps of manufacturing the IGBT, and reduce the cost.

The invention provides an insulated gate bipolar transistor (IGBT) protection circuit and a motor control system, belonging to the filed of the motor control. The IGBT protection circuit comprises a sampling circuit, a feeding back circuit, a driving circuit and a slow turn-off circuit. The IGBT protection circuit adopts the slow turn-off circuit, thus the turn-off time of the IGBT is prolonged, the current change rate is reduced and the IGBT is protected against damage when the IGBT carries out the over-current protection.

The invention discloses a transport system for a biochemical analyzer, comprising a sample feeding track, a forward track, a recovery track, a sub-track to be tested, an emergency sub-track and a return track; the sample feeding track, the forward track and the recovery track are parallel to each other Setting; said track to be tested, emergency track and return track are provided with at least one track; said track to be measured, emergency track and return track are set between the sample track and the forward track, and The sub-tracks to be tested, the emergency sub-tracks and the return sub-tracks are all perpendicular to the sample injection track and the forward track. The track conveying system can be arranged horizontally in the biochemical analyzer, and can be docked with the longitudinal track in the biochemical analyzer, so that the buffer capacity of the sample rack can be greatly increased without increasing the length of the biochemical analyzer.

The invention discloses an electro-hydraulic emergency turn-off system for a test process. The system comprises a plurality of remote control button boxes which are connected in parallel through a multi-core cable, an electric control panel which is connected with the plurality of remote control button boxes, and is provided with a data communication interface, an electromagnetic valve box which is connected with the electric control panel, an induction gas pipeline and a hydraulic control panel, wherein one end of the induction gas pipeline is connected with the electromagnetic valve box; and the hydraulic control panel is connected with the other end of the induction gas pipeline. The invention further discloses a control method of the electro-hydraulic emergency turn-off system for testing the process, the electro-hydraulic emergency turn-off system is controlled through bus control or signal input so that the ground test process is isolated from a test shaft, and the response time of the turn-off system is shortened in an electric signal control mode.

The invention discloses a switched capacitor type high-bandwidth envelope tracking power supply circuit, which includes a step wave voltage generating circuit and a class A linear amplifier, the step wave voltage generating circuit and the class A linear amplifier are connected in cascade, and the step wave voltage generating circuit The output is used as the input of a class A linear amplifier. The ladder wave voltage generating circuit is composed of n switched capacitor circuits with the same structure in series. The switching frequency of the switching tube in each switched capacitor circuit can achieve (1 / n):1 frequency reduction relative to the tracking signal frequency, and at the same time effectively expand The turn-on or turn-off time of the switch tube can be fully turned on or off to improve its working performance and reliability under high-bandwidth tracking conditions; compared with traditional methods, it can greatly reduce the number of power supplies and reduce the complexity of the circuit level and cost, and improve system efficiency.

In one embodiment, an LED driving circuit can include: (i) a sense circuit configured to sense an inductor voltage, and to generate a sense voltage signal; (ii) a protection control circuit configured to activate a first protection control signal in response to a comparison of the sense voltage signal against a first reference voltage to indicate an LED device is in a first load state; (iii) the protection control circuit being configured to activate a second protection control signal in response to a comparison of the sense voltage signal against a second reference voltage to indicate the LED device is in a second load state; and (iv) a PWM control circuit configured to control a power switch according to the first protection control signal or the second protection control signal, based on the load state of the LED device.

The invention discloses a driving control circuit and method. The power supply end of the driving control circuit is connected to a power supply circuit. In a start process, the driving control circuit is started when the voltage of the power supply end reaches starting voltage. The driving control circuit comprises a PWM signal generation circuit for generating a PWM signal used for determining turn-on time and turn-off time and used as a control signal for a switch; and an auxiliary start circuit for comparing, after the driving control circuit is started, a sampling signal representing the output voltage with first reference voltage, and entering an auxiliary start mode when the sampling signal is lower than the first reference signal. In the auxiliary start mode, the turn-off time represented by the PWM signal is prolonged to reduce switching frequency, or the turn-on time represented by the PWM signal is prolonged to increase an output voltage rise rate.

The invention discloses a rail conveying system for a biochemical analyzer. The rail conveying system comprises a first bracket, wherein the first bracket is provided with a conveying belt assembly and a limit baffle mechanism. The limit baffle mechanism is arranged at the sample outlet end of the conveying belt assembly; the limit baffle mechanism is used for restricting the sample rack on the sample outlet end of the conveying belt assembly; the first bracket is further provided with a pushing mechanism. The pushing mechanism is used for urging the sample rack on the sample outlet end of the conveying belt assembly away from the conveying belt assembly. The rail conveying system can be set horizontally in the biochemical analyzer to realize the butt joint with the longitudinal rail in the biochemical analyzer, so that the buffer amount of the sample rack can be greatly increased on the premise of not increasing the length of the biochemical analyzer.