704 results about "Triode" patented technology

The utility model relates to a rear-phase-cut single-live-wire type wall light modulator, which comprises an MOS (Metal Oxide Semiconductor) tube switch loop unit, a singlechip control unit and a direct-current power supply unit, the MOS tube switch loop unit comprises a wiring terminal J2 connected with an MOS tube Q1, a grid electrode of the MOS tube Q1 is connected with four resistors in series in sequence and then is connected with an MOS tube Q2, a drain electrode of the MOS tube Q2 is connected with a diode D2, the diode D2 is connected with a diode D1, a fixed end contact of a single-pole double-throw switch is connected with the MOS tube Q2, and two movable end contacts of the single-pole double-throw switch are connected with the wiring terminal J1 and the wiring terminal J3 respectively; the direct-current power supply unit comprises an alternating-current voltage waveform acquisition circuit, a direct-current voltage drop circuit, an overcurrent protection circuit and a filtering voltage stabilizing circuit; according to the single-chip microcomputer control unit, a linear sliding potentiometer is connected with the PC2 end of a single-chip microcomputer after being connected with a resistor in series, the linear sliding potentiometer and a rotary potentiometer are sequentially connected between the output end of the direct-current power supply unit and the ground in series, a triode Q6 is connected with a triode Q5 and then connected with the collector electrode of a triode Q7, and the base electrode of the triode Q7 is connected with the PA6 end of the single-chip microcomputer after being connected with a resistor in series.

The application relates to a high-order curvature compensation band gap reference circuit, which comprises a first-order band gap reference circuit, a high-temperature region curvature compensation circuit and a starting circuit. The first-order band gap reference voltage is realized by the following technologies: the voltage generated by the current of PMOS tube M4 on resistors R3-R4 and the voltage generated by the current of PMOS tube M6 on resistor R4 both have positive temperature coefficients, the voltage generated by the current of PMOS tube M5 on resistors R3-R4 and the voltage generated by the current of PMOS tube M7 on resistor R4 both have negative temperature coefficients; the working area of NMOS tube M13 gradually changes from the deep triode region, the triode region to the saturation region with the increase of temperature by controlling the working of NMOS tube M13 by the technology that the gate voltage of NMOS tube M12 increases with the increase of temperature, so that the current of PMOS tube M14 is high-order nonlinear with temperature, and the first-order band gap reference voltage is temperature compensated, thereby obtaining the high-order temperature compensation band gap voltage.

The invention relates to the technical field of power electronics, and provides a power supply slow start circuit and power supply equipment based on triode control, the slow start circuit comprises a power supply, a switch module, a load and a slow start control module, the power supply, the switch module and the load form a power supply loop, the slow start control module is connected with the power supply and the switch module, when the power supply powers on a load, a triode in the slow start control module is controlled to be in an amplification region, and the driving current of the switch module is shunted, so that the duration of the switch module in a Miller platform is prolonged; and the switch module is in a complete conduction state, so that the slow start of the load is realized. According to the slow start circuit, the conduction degree of the switch module can be controlled through the triode, and the duration of the switch module on a Miller platform is prolonged, so that surge suppression of load energizing current is realized, the adaptability is high, the interference resistance is strong, and the circuit stability is improved.

The utility model discloses a power supply input surge protection and isolation device, which comprises a piezoresistor, a surge decoupling power resistor and a TVS (Transient Voltage Suppressor) tube which are sequentially connected in series, and a self-adaptive surge control circuit which is connected with the surge decoupling power resistor in parallel, when surge overvoltage occurs, the TVS tube is firstly broken down, and transient large current flows through the adaptive surge control circuit; the surge decoupling power resistor is used for enabling the passing surge current to generate relatively large voltage drop after the TVS tube is broken down; the self-adaptive surge control circuit comprises a first MOS tube which is used for conducting transient large current passing through a TVS (Transient Voltage Suppressor) tube; when the voltage drop on the MOS tube is greater than the breakdown voltage of the voltage-regulator tube, the voltage-regulator tube is broken down to trigger the conduction of the triode; when the voltage-regulator tube is broken down, the triode is conducted, so that the GS voltage drop of the first MOS tube is reduced, and the first MOS tube is turned off; when the sum of the clamping voltage of the TVS tube end and the voltage drop of the surge decoupling power resistor exceeds the minimum action voltage of the piezoresistor, the piezoresistor acts, so that high-energy transient interference flows through the piezoresistor, and surge protection is realized. According to the utility model, the surge protection and isolation protection functions of the input end of the power supply can be effectively realized, and the safety and stability of the use of the power supply are ensured.

The embodiment of the invention provides a power driving circuit, and relates to the technical field of vehicles. The device is suitable for the technical field of various new energy vehicles such as electric vehicles, hybrid power vehicles and fuel cell vehicles. The circuit comprises a power supply, a sampling resistor, an MOS tube, a current monitoring unit, a comparator, a triode and a micro-control unit. The power supply is connected with the MOS tube through the sampling resistor, and the MOS tube is used for being connected with a power load; the sampling resistor is connected with a first signal input end of the micro-control unit through the current monitoring unit, and a second signal input end of the micro-control unit is connected with an output end of the MOS tube; the output end of the current monitoring unit is connected with the input end of the comparator, the output end of the comparator is connected with the input end of the triode, and the output end of the triode is connected with the MOS tube. The method provided by the invention effectively solves the problems that the cost of power driving power is relatively high and the protection requirement of the domain control device cannot be met in the prior art.

The invention provides a unidirectional ultra-low voltage electrostatic protection device which comprises a TVS main device and a low voltage trigger unit, the TVS main device comprises an N-type heavily doped substrate and a P-type epitaxial layer, and a first P + heavily doped active region, an N + heavily doped active region and a second P + heavily doped active region are arranged in the P-type epitaxial layer. The first P + heavily-doped active region, the N + heavily-doped active region and the second P + heavily-doped active region are matched with one another to form an NPN-type triode, the lower surface of the N-type heavily-doped substrate can be connected with a first I / O port, the N + heavily-doped active region and the second P + heavily-doped active region can be connected with a second I / O port, and the low-voltage trigger unit is arranged between the first I / O port and the first P + heavily-doped active region. The low-voltage trigger unit can rapidly conduct a PN junction formed by the first P + heavily-doped active region and the N + heavily-doped active region in a positive bias mode. The electrostatic protection device has the beneficial effect that the turn-on voltage of the electrostatic protection device can be reduced.

The invention relates to the technical field of battery charging protection circuits, and discloses a battery charging overcurrent checking circuit which comprises a triode PNP0, a substrate of a charging power tube PM0 is electrically connected with a base electrode of a PNP type triode PNP0, an emitting electrode of the triode PNP0 is connected with charging input voltage VIN, a collector electrode of the triode PNP0 is connected with one end of a resistor R1, and the other end of the resistor R1 is grounded; the negative input end of the comparator COMP is connected to a connection node of the triode PNP0 and the resistor R1 to obtain voltage VC, the output end of the reference voltage generation module is electrically connected with the positive input end of the comparator COMP to obtain reference voltage Vref, the output end of the comparator COMP outputs an overcurrent detection signal, substrate current of the charging power tube PM0 is adopted as a detection signal source, and the voltage Vref is detected through the detection signal source. A detection circuit is built by matching a PNP type triode PNP0 and a resistor R1, and an additional reference PMOS tube and a continuously working reference current source are omitted, so that the chip layout area is saved, and miniaturization of a charging chip is facilitated.

The utility model provides a power supply overvoltage protection circuit. Comprising a control network module and a turn-off module, the control network module comprises a voltage stabilizing diode, a first resistor, a second resistor and a PNP triode, one end of the first resistor is connected to a power input end, and the other end of the first resistor is connected with the second resistor and the voltage stabilizing diode; and the turn-off module comprises a field effect transistor, the first resistor and one end of an E electrode of the PNP triode are jointly connected to a source electrode of the field effect transistor, one end of a C electrode of the PNP triode is connected to a grid electrode of the field effect transistor, and the turn-off module is used for performing turn-off control on the field effect transistor to realize an overvoltage protection function. The power supply overvoltage protection circuit provided by the utility model has the advantages of simple structure, quick response, simplicity, high efficiency and low cost.

The utility model relates to a phase change thermo-acoustic engine experimental device which comprises a thermo-acoustic conversion system and an acoustic-electric conversion system. The thermo-acoustic conversion system comprises a sound production module and a Helmholtz resonant cavity, a ceramic plate stack soaked with water exists in the sound production module, and the stable temperature difference needed for generating the thermo-acoustic effect at the two ends of the ceramic plate stack is reduced. Sound waves generated by the thermoacoustic effect form standing waves in the Helmholtz resonant cavity, and the sound intensity is amplified; the acoustic-electric conversion system comprises piezoelectric ceramics and a triode common-emitter amplification circuit, the piezoelectric ceramics are arranged at the tail end of the resonant cavity and convert acoustic energy into electric energy, and the electric energy is amplified by the triode common-emitter amplification circuit and then drives a nixie tube to display. The experimental device integrates thermodynamics, fluid mechanics, acoustics, material science and electronic technology, has the characteristics of simple structure, low cost, rich physical process and strong exploration, is suitable for experimental teaching, particularly suitable for new engineering teaching requirements, and is beneficial to improving the multidisciplinary cross practice ability of students.

The invention provides a band-gap reference circuit, a current compensation method and a reference power supply. The band-gap reference circuit comprises a first triode module, a second triode module, a first resistor module, a second resistor module, a first compensation branch and a second compensation branch, the first compensation branch generates first compensation current, and the first compensation current compensates first current flowing into a third end of the first triode module from a first end of the first triode module. The first compensation current is equal to the first current. The second compensation branch generates second compensation current, the second compensation current compensates second current flowing into the third end of the second triode module from the first end of the second triode module, and the second compensation current is equal to the second current. The problems that the precision of the reference voltage output by the band-gap reference circuit is reduced, the temperature drift is increased, and the stability and reliability of the reference voltage are seriously influenced due to the fact that an existing band-gap reference circuit cannot guarantee accurate matching of collector currents of two branches of BJTs are solved.

The utility model discloses a kind of drive circuits, belong to electric bicycle instrument technical field, specifically related to a kind of electric bicycle instrument drive circuit, comprising: conversion module, output filter and high voltage surge suppression module;Output filter and high voltage surge suppression module are connected with conversion module;Conversion module includes: MOS tube Q6, MOS tube Q9, resistance R20, resistance R19, resistance R18, triode Q5 and triode Q10;Output filter includes: inductance L2, electrolytic capacitor C15, electrolytic capacitor C14, capacitor C13;High voltage surge suppression module includes: transient voltage suppression diode D5;The utility model uses wide input voltage range, high-efficiency switching power supply, replaces traditional linear voltage stabilizer, and efficiency is higher, and heat is smaller, and tolerance to input voltage fluctuation is better, while increasing greater capacity input electrolytic capacitor, effectively absorb transient surge and fill transient voltage drop, in addition, TVS diode is used to suppress high voltage surge, and self-recovery fuse is used to prevent overcurrent.

A semiconductor plug arrangement system and arrangement method, the system comprises: a vibrating disc, the inner wall is provided with a spiral material plate, the end of the spiral material plate is connected with a main material groove extending to the outside of the vibrating disc. A spiral groove is formed on the inner wall of the vibrating disc corresponding to the connecting part of the spiral material plate; a notch is formed on one side of the middle section of the main material groove, the width of the notch is greater than or equal to half of the width of the bottom plate of the main material groove, the notch is connected with a branch material groove, the branch material groove is communicated with the main material groove, a stop rod is arranged on the inner wall of the side plate opposite to the notch of the main material groove in parallel, the stop rod has a gap between the bottom plates of the main material groove, a notch is formed on the middle section of the stop rod, the width of the notch is greater than the width of the pin; the end of the branch material groove and the end of the main material groove are respectively connected to two ends of an arc track, and a material taking point is arranged on the middle section of the arc track. The scheme can multiply the number of triodes arranged and output by the vibrating disc, and effectively reduces the influence on the plug-in equipment lifting efficiency.

The utility model relates to a low-cost protection circuit which comprises an input circuit, the output end of the input circuit is electrically connected with the power supply ends of a first control circuit, a second control circuit and an output control circuit at the same time, and the output end of the first control circuit is electrically connected with the grounding ends of the second control circuit and the output control circuit at the same time. The output end of the second control circuit is electrically connected with the control end of the output control circuit, and the input circuit, the first control circuit, the second control circuit and the output control circuit are all composed of discrete components. According to the scheme, the low-cost protection circuit is only composed of the two MOS tubes, the two voltage stabilizing diodes, the triode, the resistor, the capacitor and the switch, has the advantages of being simple in circuit and low in cost, and can achieve multiple protection functions of power supply overvoltage, undervoltage, reverse connection and surge current impact at the same time. The performance is reliable, an IC or an optocoupler or a single-chip microcomputer chip does not need to be arranged, programming codes are not needed, production is convenient, and the production efficiency is improved.

The embodiment of the present specification provides a synchronization trigger system and method for a pulse wind tunnel, the system comprising: a signal trigger module, a light source control module and a device control module; the signal trigger module is used for receiving a reference signal; the sending device and the receiving device for the reference signal are electrically isolated based on a circuit structure; the reference value of a trigger signal is set according to the isolated reference signal; whether the light source and the device are turned on or not is indicated according to the trigger signal and the reference value; the light source control module is used for controlling the flicker frequency of the light source based on a MOSFET and a triode; the device control module is used for controlling the start and stop of the device according to a preset delay. The technical scheme provided in the present application is used to solve the problem that the risks among the sub-circuits are related to each other and the performance applicability is not strong.

The application discloses a vertical parasitic NPN triode device and a manufacturing method thereof, and the vertical parasitic NPN triode device comprises the following steps: an N-type deep well is arranged on a P-type substrate, the N-type deep well is formed into a segmented structure on both sides of the P-type substrate at a corresponding position of an emission area, both ends of the segmented N-type deep well are connected to each other, and the N-type deep well serves as a collector area; a shallow trench isolation is arranged on an N well and a P well, the N well is arranged in the N-type deep well; the P well is arranged on an inner side of the segmented N-type deep well between the N wells, and serves as a base area; an N-type heavily doped area is arranged on a surface of the P well, and serves as the emission area; and a P-type heavily doped area is arranged on the surface of the P well, is arranged on both sides of the N-type heavily doped area, and is electrically connected to the P well to serve as a base area lead-out end. The application can overcome the defect that the low Early voltage of the existing vertical parasitic NPN triode is caused by the low net doping concentration of the base area, and meanwhile, the adverse effects caused by directly increasing the P well concentration of the base area on other devices of a process platform can be avoided.

The invention discloses a molten salt energy storage device and method based on nitrate, and the device comprises a plurality of resistors, a plurality of MOS tubes, a plurality of operational amplifiers, a plurality of diodes, a triode, a capacitor, a solid-state relay, a potentiometer, and a counter. The output end of an operational amplifier U7 in the plurality of operational amplifiers is connected with five pins of the potentiometer U2, and the anti-phase end inputs a temperature parameter signal IN1; the in-phase end is connected with eight pins of the potentiometer U2 and one end of the resistor R5; the six pins of the potentiometer U2 are connected with one end of a resistor R16 and the drain electrode of a PMOS tube Q2; the grid electrode of the PMOS transistor Q2 is connected with the output end of the operational amplifier U8, and the source electrode is connected with a power supply and meets the positive voltage requirement; the inverting end of the operational amplifier U8 is connected with a reference signal, and the in-phase end of the operational amplifier U8 is connected with the grid electrode of the NMOS tube Q1, one end of the resistor R4 and the collector electrode of the NMOS tube Q1; a base electrode of the triode U1 is connected with one end of the resistor R6; the drain electrode of the NMOS tube Q1 is connected with the other end of the resistor R6, one end of a resistor R7 and four pins of the solid-state relay U3; the other end of the resistor R7 is connected with one end of the capacitor C1.

The utility model relates to the technical field of industrial semiconductors, and discloses a device for detecting the working state of a lamp holder of ultraviolet light curing equipment, which integrates temperature, wind pressure and ultraviolet light intensity detection functions by optimizing the structure of a hardware circuit. The circuit comprises a switch type capacitor voltage converter, a linear voltage regulator, a phototriode, an NTC thermistor, a partial pressure sensor and a CAN communication module. Through the bidirectional TVS diode, RC filtering and two-stage voltage stabilization design, the anti-electromagnetic interference capability is improved, and the signal transmission reliability is improved; temperature, wind pressure and illumination detection circuits are integrated on a single board, the structure is simplified, and the space is saved; the standby energy consumption of the sensor is reduced through hardware power management; by comprehensively optimizing the circuit structure and the signal transmission path, the detection reliability of the working state of the lamp holder of the ultraviolet curing equipment is improved.

The invention discloses a novel elevator light curtain which comprises an all-plastic shell and a circuit board arranged in the all-plastic shell. The circuit board adopts a cascade multi-path switching module to gate a plurality of photoelectric units, and a grounding filter network is arranged at the output end of each photoelectric unit for source filtering; an active filtering buffer unit with a PNP triode as a core is introduced into a signal path, and a signal processing module comprising a four-stage operational amplifier and a gradient RC filtering network is adopted for step-by-step amplification and conditioning. Through systematic hardware circuit design, on the premise of not depending on metal shielding, internal and external electromagnetic interference is actively and multiply inhibited from the source to the terminal, meanwhile, the structure is simplified, the cost is reduced, the short circuit and failure risks possibly caused by shell grounding are thoroughly avoided, and higher reliability, environmental adaptability and economical efficiency are achieved.

This application discloses an MCU sleep / wake-up circuit, including a signal circuit, a second sleep control transistor Q2, a first hierarchical sleep control transistor Q1, an LDO chip U, and a control unit MCU. The signal circuit outputs a wake-up signal. The base of the second sleep control transistor Q2 is connected to the output terminal of the signal circuit through a current-limiting resistor R4, grounded through a voltage divider resistor R9, and connected to the enable terminal ENA through a current-limiting resistor R3. The enable terminal ENA is connected to the control unit MCU, the emitter is grounded, and the collector outputs a control signal. The control signal is input to the first hierarchical sleep control transistor Q1 through a bias voltage divider circuit. The emitter of the first sleep control transistor Q1 is connected to the power supply VIN, and the collector outputs the power supply voltage to the LDO chip U. The LDO chip U outputs its operating voltage to the control unit MCU. When the control unit MCU is working, it outputs a high level to the enable terminal ENA. This application can reduce the complexity of the sleep / wake-up system and achieve low-power sleep and reliable wake-up of the control unit MCU.

The utility model discloses an MOS tube hard switch control surge suppression circuit, which belongs to the technical field of power electronics, and comprises a control circuit, a drive circuit and a power switch circuit, the power switch circuit is composed of a high-power suppression resistor, a first MOS tube and a second MOS tube, the first MOS tube and the second MOS tube are connected in parallel, the source electrode of the MOS tube is connected with the positive electrode of the output power supply through the high-power suppression resistor, and the drain electrode of the MOS tube is connected with the negative electrode of the output power supply. Compared with the prior art, the control circuit of the circuit can automatically detect the voltage and change the conducting state of the triode based on the change of the voltage so as to control the on-off state of the MOS tube, when the voltage is too large, the high-power suppression resistor will intervene in the circuit to consume the voltage spike, it is ensured that the rear-end power supply voltage is stable, and the purpose of protecting rear-end equipment is achieved.

The invention provides a high-precision voltage-stabilizing constant-current power supply for continuous discharge of a CO2 laser, which relates to the technical field of high-voltage voltage-stabilizing constant-current power supplies and comprises a high-voltage direct-current voltage-stabilizing power supply and a high-impedance amplification loop. The high-voltage direct-current voltage-stabilized power supply is boosted by a transformer, rectified by a rectifier bridge and stabilized by a filter capacitor, and continuously adjustable high-voltage output of 0-30kV is provided; the high-impedance amplification loop is composed of an operational amplifier, a three-stage triode amplification circuit and an electronic tube, the output impedance reaches up to 650 megohms, and the high-impedance amplification loop has the excellent constant-current characteristic. The power supply can accurately adjust the output current in the range of 0-30mA, the current fluctuation is less than one thousandth, the power supply can continuously and stably operate for more than 18 hours, and the power supply is suitable for laser discharge control in a high-temperature and high-density plasma environment. According to the invention, high-precision output is realized by adopting common performance devices, the advantages of voltage resistance, overload resistance and cost are considered, and the problems of poor current stability and inconvenient adjustment of a traditional laser power supply are solved.

The utility model discloses a passive adjustable voltage clamping circuit with a temperature protection function, which comprises an input positive end IN +, an input negative end IN-, a diode D1, a diode D2, a diode D3, a triode Q1, a field effect transistor Q2, a triode Q3, a controllable precise voltage stabilizing source N1, a temperature sensor RT1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a slide rheostat R8, the input positive end IN + and the input negative end IN-serve as input power sources, the clamping circuit works passively and can bear very high power, and the bearing power depends on the peak power of the field efficiency tube; the clamping voltage is adjustable, the voltage precision is high, the error is controlled below 1%, the field effect transistor Q2 has an over-temperature protection function, the circuit is prevented from being damaged due to thermal breakdown when external high voltage lasts for a long time, the circuit is simple, the circuit is composed of discrete components, the cost is low, implementation is easy, and the cost performance is high.

The application belongs to the technical field of electronic circuits, and particularly relates to a low-temperature-drift high-PSRR op-amp-free bandgap reference circuit, which comprises MOS tubes M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11, M12, M13, M14, M15, triodes Q1, Q2, Q3, resistors R1, R2 and R3; compared with the prior art, the circuit is an op-amp-free bandgap reference circuit, which avoids the influence of op-amp offset voltage on reference voltage and improves the accuracy of the reference voltage; the temperature coefficient of the reference voltage can be well adjusted by adjusting the resistance coefficient, so that the low-temperature-drift reference voltage is realized.

The utility model discloses a microwave motion inductive device, including circuit board, power interface, output interface, paster relay, circuit board has welded radio frequency module, radio frequency module electric connection has resistance module group and condenser module group, and power interface passes through triode and resistance module group and condenser module group and radio frequency module electric connection, and output interface and radio frequency module electric connection, and paster relay is welded on the circuit board, and paster relay is connected in parallel with triode, and paster relay passes through circuit board and resistance module group and condenser module group and radio frequency module electric connection, through triode to the power of power interface input plays the voltage stabilizing and current limiting effect, ensures radio frequency module and paster relay stable work, and the peak value and duration of surge current can be reduced with resistance module group, condenser module group, limit surge current size, improve radio frequency module and paster relay stable service life, and service life is long.

The utility model relates to a hardware decoupling circuit of a power module temperature output and protection signal multiplexing pin, comprising a power module composite pin which has a temperature signal output function and a fault signal output function; the decoupling circuit is connected with the power module composite pin and is used for decoupling the temperature signal and the fault signal output by the power module composite pin, so that the temperature signal and the fault signal output by the power module composite pin are separated and can be independently output; wherein the decoupling circuit is formed by connecting a triode Q1, a resistor assembly, a capacitor assembly, a power supply end VCC, a first grounding end GND1, a second grounding end GND2, a temperature signal output end T-IPM and a fault signal output end IPM-F0, and the power module composite pin is simultaneously connected with the triode Q1 and the resistor assembly. According to the hardware decoupling circuit provided by the utility model, the reliability and the accuracy of processing the temperature signal and the fault signal of the power module are improved.

This invention discloses a primary-side feedback output no-load voltage stabilization circuit, including a transformer T1. One end of the N1 coil of the transformer T1 is connected to the voltage feedback pin of the main control unit U1, and the other end is grounded. One end of the N2 coil of the transformer T1 is connected to the collector of the transistor Q2 through a diode D2, and the VCC voltage output from the emitter is supplied to the VDD terminal of the main control unit U2. The cathode of the diode D2 is grounded through a capacitor EC1, and the cathode is also connected to the voltage terminal through resistors R9 and R10 respectively. The cathode of the diode D2 is also connected to the base of the transistor Q2 through a resistor R11, and the base is also grounded through a Zener diode ZD1.

This invention provides a low-level mute circuit, comprising: a first audio input terminal, a first audio operational amplifier circuit, a first audio differential output terminal, a mute circuit, a second audio input terminal, a second audio operational amplifier circuit, and a second audio differential output terminal. The mute circuit includes a first mute control terminal and a second mute control terminal. When there is a signal input at the first audio input terminal and no signal input at the second audio input terminal, the second mute control terminal outputs a low level, and the mute circuit controls the second audio differential output terminal to be pulled low to ground. When there is a signal input at the second audio input terminal and no signal input at the first audio input terminal, the first mute control terminal outputs a low level, and the mute circuit controls the first audio differential output terminal to be pulled low to ground. This invention controls the amplification or mute of the audio input signal by controlling the conduction or cutoff of a transistor through the high or low level of the mute signal output.

The invention discloses a source-type and drain-type switching value protection circuit and system. The source-type and drain-type switching value protection circuit comprises a PMOS (P-channel Metal Oxide Semiconductor) tube Q4, a resistor R1 and a PMOS tube Q2 which are connected in series, a resistor R13 and a resistor R12; a voltage drop control unit; the output end of the comparator U10B is connected between the resistor R2 and the resistor R9 through the resistor R3, and the grid electrode of the PMOS tube Q4 is connected between the resistor R2 and the resistor R9; the grid electrode of the PMOS transistor Q2 is connected with the collector electrode of the NPN type triode Q6, and the base electrode of the triode Q6 is connected with the output end of the controllable logic gate U1A; the input end of the controllable logic gate U1A is used for receiving a first voltage signal, and the enable end of the controllable logic gate U1A is used for receiving an enable signal output by the output end of the comparator U8B; wherein the positive electrode of the comparator U8B is connected with the reference voltage Vref1, and the other end of the comparator U8B is connected between the resistor R13 and the resistor R12, so that the reliability of the switching value output channel is improved.

The utility model discloses a high-efficiency low-cost high-voltage ignition detection circuit, which belongs to the technical field of high-voltage power supply electronics and comprises a high-voltage current detection resistor, a piezoresistor, a filter capacitor, a blocking capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first triode and a second triode. By means of the mode, faults such as electric field ignition and arcing can be found rapidly, meanwhile, the method is suitable for ignition detection of power supplies with different power sizes, positive and negative high-voltage power supplies can conduct effective ignition detection, and the anti-interference capacity is high.

The utility model discloses a special control operation power supply device for an underground high-voltage explosion-proof cabinet, which belongs to the technical field of electrical tests and comprises an inversion unit, a transformer and a frequency converter. The inversion unit comprises an inverter, a power switch and a rechargeable battery; the inverter comprises a resistor R1, a resistor R2, a triode Q1 and a triode Q2; one end of the resistor R1 is connected with the base electrode of the triode Q1, and the other end of the resistor R1 is connected with the collector electrode of the triode Q2 and the output end of the high-voltage winding of the transformer; one end of the resistor R2 is respectively connected with the collector of the triode Q1 and the input end of the high-voltage winding of the transformer, and the other end is connected with the base of the triode Q2; the emitters of the triode Q1 and the triode Q2 are connected with the power switch; the power switch is connected with the negative electrode of the rechargeable battery; the positive electrode of the rechargeable battery is connected with the high-voltage winding of the transformer; and a secondary winding of the transformer is connected with the frequency converter, so that the technical problem of inaccurate test data caused by a no-voltage protection mechanism during an underground electrical test in the prior art is solved.