986 results about "Audion" patented technology

The invention discloses a power MOS pipe grid drive circuit and method for grid floating and level switching. The drive circuit of the invention includes an upper pipe drive circuit and a lower pipe drive circuit, and is characterized in that the upper pipe drive circuit includes a first resistance, a second resistance, a third resistance and a fourth resistance, a bootstrap capacitance, a second capacitance, a first diode and a second diode, a first PNP type audion and a second PNP type audion, as well as a first NPN type audion; the lower pipe drive circuit includes a fifth resistance, a sixth resistance, a seventh resistance, an eighth resistance and a ninth resistance, a third capacitance and a fourth capacitance, a third diode, a third PNP type audion and a fourth PNP type audion as well as a second NPN type audion. The method can realize to convert grid drive level of upper and lower power MOS pipes, drive lower pipe grid and drive upper pipe grid floating. The invention does not adopt any drive chip, only consists of common discrete elements like resistance, capacitance and audion, etc, and has the advantages of low cost, high reliability and stability, as well as high drive efficiency.

An input voltage sampling compensating circuit comprises a first resistor for electro-static discharge (ESD) resistor voltage drop compensating, a zero potential temperature compensating audion, an operational amplifier, a second resistor for biasing or current limiting, a clamping audion, a feed-forward current image current mirror and a sampling trigger port. An emitter electrode of the compensating audion is grounded, a base electrode and a collector electrode are connected and then connected with one end of the first resistor; the other end of the first resistor is connected with a working power supply and the in-phase input end of the operational amplifier respectively, the output end of the operational amplifier is connected with a base electrode of the clamping audion through the second resistor, the base electrode is connected with the output end of the sampling trigger port, an emitter electrode of the clamping audion is used for being connected with the external ESD resistor, and a collector electrode is connected with the input end of the feed-forward current image current mirror; the power end of the feed-forward current image current mirror is connected with the working power supply, and the compensating current output end of the feed-forward current image current mirror is connected with the other end of the first resistor. The circuit is capable of compensating for the voltage drop on the ESD resistor, provided with a temperature self-compensating function and free of influences from the ESD resistor and the temperature.

The invention discloses an IOT-based industrial control system. The IOT-based industrial control system comprises a signal receiving circuit, a signal calibration circuit and a voltage-stabilizing output circuit; the signal receiving circuit receives signals of the input end of a signal transmission channel for a control terminal in the IOT-based industrial control system; the signal calibration circuit is divided into two channels for receiving output signals of the signal receiving circuit; one channel detects abnormal high-level signals by using a composite circuit composed of an audion Q1and an audion Q2; the other channel performs same-phase amplification by using an operational amplifier AR1; after same-phase amplification is carried out by the operational amplifier AR1, signals arerespectively amplified through an operational amplifier AR2 and attenuated through a variable resistor RW1; finally, after performing same-phase amplification by using an operational amplifier AR5, the voltage-stabilizing output circuit performs output after stabilizing voltage through a voltage-stabilizing circuit composed of an audion Q5 and a voltage-stabilizing tube D4; signals can be automatically calibrated; signal stability can be ensured; and thus, signal disturbance is prevented.

The invention relates to a power battery thermorunaway automatic alarm device and method used for monitoring and alarming thermorunaway of power battery single bodies. The automatic alarm device comprises multiple fuse elements and further comprises a control circuit and a warning indicator, and all the fuse elements are arranged on all the battery single bodies or battery packs formed by two or more battery single bodies and fuse when surface temperature of a certain battery single body or battery pack reaches a certain threshold value; all the fuse elements are sequentially connected in series to form a fuse element string, one end of the fuse element string is sequentially connected with the control circuit and the warning indicator, the other end of the fuse element string is grounded, and the control circuit uses the audion connection characteristics when the fuse elements fuse for controlling the warning indicator to act to automatically give an alarm. The automatic alarm device is simple in structure, low in cost and high in practicability, achieves real-time monitoring of thermorunaway of the battery single bodies connected in parallel or series in the power battery packs and improves safety and reliability of heat management on the power battery packs.

The invention provides a sub-threshold value MOS (metal oxide semiconductor) tube-based overheat protection circuit which comprises a temperature detecting circuit, a voltage comparer and an output shaping circuit, wherein the temperature detecting circuit is in output connection with the voltage comparer, the voltage comparer is in output connection with the output shaping circuit, the output shaping circuit is in feedback connection with the temperature detecting circuit, and the output shaping circuit generates an output voltage for controlling follow-up circuits. The temperature detecting circuit consists of an MOS image current source of a sub-threshold value region and a resistance network, and the voltage comparer adopts a push-pull type two-stage voltage comparer. An audion is not used in the circuit, so that the accuracy of the temperature detecting circuit can be improved; and therefore, the overheat protection circuit is suitable for the common CMOS (complementary metal-oxide-semiconductor transistor) technology.

The invention provides an LED drive control circuit suitable to the technical field of lighting circuits, which comprises a singlechip, an audion, an MOS (Metal Oxide Semiconductor) tube, a power inductor and a constant current integrated chip, wherein a power input pin and a power output pin of the singlechip are respectively connected with the anode and the cathode of a power input end; the base electrode of the audion is connected with the singlechip, and the emitting electrode of the audion is connected with the cathode of the power input end; the grid electrode of the MOS tube is connected with the collector electrode of the audion through a divider resistor, and the source electrode of the MOS tube is connected to the anode of the power input end; one end of the power inductor is connected with the drain electrode of the MOS tube, the other end of the power inductor is connected with the anode of a diode, and the cathode of the diode is connected to the anode of an LED; a working enable pin of the constant current integrated chip is connected with the singlechip, a feedback pin of the constant current integrated chip is connected to the cathode of the LED for sampling current, and a power pin is connected to a node arranged between the power inductor and the anode of the diode. The LED drive control circuit is realized by adopting the constant current integrated chip with low cost and high efficiency, can ensure stable and reliable work of the LED, and has very simple structure.

The invention relates to a bidirectional silicon controlled trigger circuit with low cost and better reliability. The bidirectional silicon controlled trigger circuit comprises a first audion, a second audion, a transformer, a capacitor and bidirectional silicon controlled, wherein the first audion is cut off when the input port of a control signal is in low electrical level, a direct-current power supply charges the capacitor to drive the second audion to be in saturated conductivity, the primary coil of the transformer is stimulated, so that the secondary coil of the transform outputs positive driving voltage by a third diode, the bidirectional silicon controlled is conducted, and the load is electrified; when the capacitor is completely charged, the second audion is cut off, the third diode is in the reverse cutoff state, and the load is in outage; when the input port of the control signal is controlled to be in high electrical level, the first audion is conducted, the capacitor, the first audion and a fifth resistor form a discharging circuit until electricity on the capacitor is completely discharged; and then, above steps are repeated when the input port of the control signal is in the low electrical level.

The invention relates to a door lock control system based on NFC (Near Field Communication) and a method thereof, wherein the door lock control system based on NFC comprises a double-MOS (metal oxide semiconductor) transistor, a resistor R1 connected with the input end of the double-MOS transistor, an audion Q1 connected with the output end of the double-MOS transistor, a relay U1 connected with the audion Q1, an electromagnetic lock J1 connected with the output end of the relay U1, a diode D1 connected with the relay U1 in parallel, and a power supply E used for supplying power for the double-MOS transistor and the relay U1. The door lock control system based on NFC solves the technical problem that the traditional door lock brings trouble to users frequently. The safety information is stored into an NFC mobile phone terminal in advance by using the NFC technology, and then a door lock is controlled to be locked and unlocked through the door lock system formed by the NFC terminal and an intelligent lock system, thus the door lock control system not only is convenient for daily life, but also has higher safety.

The invention discloses an isolation transmission method of a switching power supply and a circuit thereof. Error signals sampled by a sampling circuit are sequentially output through an isolation circuit and a rectification filter circuit; the isolation circuit is composed of an isolation transformer, a driving triode and a pulse signal source, and the pulse The signal source outputs a pulse signal with a fixed frequency and pulse width, and the pulse signal is mixed with the error signal output by the sampling circuit through the driving triode in the primary winding of the isolation transformer, and the mixed signal is output from the secondary winding of the isolation transformer to the rectification filter circuit, It is rectified and filtered by a rectifying and filtering circuit to output a DC level signal whose amplitude is controlled by an error signal; the isolated transmission method and its circuit of the present invention have high transmission ratio for transmitting small signals, are less affected by temperature changes, and are resistant to radiation With the characteristics of strong capability, good stability and high derating, it is suitable for applications in high and harsh environments such as aerospace, military industry, and communications.

The invention discloses a backlight driving circuit. The backlight driving circuit comprises a voltage stabilizing circuit, a boost circuit and a control circuit. The voltage stabilizing circuit receives input voltage, filters the input voltage and outputs voltage stabilizing direct current. The boost circuit is connected with the voltage stabilizing circuit, receives the voltage stabilizing direct current, boosts and outputs the voltage stabilizing direct current to a light emitting diode (LED) light bar. The control circuit is connected with the boost circuit and is used for supplying a pulse width modulation (PWM) square wave and controlling the boost circuit to supply power for the LED light bar. The boost circuit comprises a metal oxide semiconductor (MOS) pipe or an audion. At least three resistors with near or same value of resistance are in parallel connection between a source electrode of the MOS pipe or a collector of the audion and the ground. Accordingly, the invention further provides a liquid crystal display adopting the backlight driving circuit. The backlight driving circuit and the liquid crystal display can improve the accuracy of the current output to the LED light bar.

The invention relates to a high-precision resistance-free band-gap voltage reference source. The high-precision resistance-free band-gap voltage reference source comprises a minus-temperature current generating circuit, a right-temperature current generating circuit, a first-order right-temperature voltage overlaying circuit, a low-temperature current compensating circuit and a high-temperature current compensating circuit. The minus-temperature current generating circuit is used for generating minus-temperature currents. The right-temperature current generating circuit is used for generating right-temperature currents. One base electrode of the right-temperature current generating circuit and an emitting electrode of a PNP audion Q1 with a collector electrode grounded are connected to the first-order right-temperature voltage overlaying circuit, right-temperature currents supply bias currents to the first-order right-temperature voltage overlaying circuit, the first-order right-temperature voltage overlaying circuit achieves overlaying between right-temperature voltage and minus-temperature voltage and outputs a VREF. The high-precision resistance-free band-gap reference voltage source has the very good temperature features, and can provide higher voltage reference precision. A resistor model is not adopted in the high-precision resistance-free band-gap voltage reference source, and the high-precision resistance-free band-gap voltage reference source can be compatible with certain low-precision technologies without resistors or resistor modules.

The invention discloses a portable meteorological measuring instrument control system, which comprises a frequency collection circuit, a wave detection feedback circuit and an operational amplification voltage stabilizing circuit, wherein the frequency collection circuit collects analog signal frequency when the portable meteorological measuring instrument works; the wave detection feedback circuit applies an operational amplifier AR1 and an operational amplifier AR2 to form a wave detection circuit to carry out signal wave detection on a frequency collection circuit output signal; meanwhile,an audion Q3, an audion Q5, a diode D6 and a diode D7 are used for forming a push-pull circuit; finally, through a buffer circuit formed by a resistor R12, a capacitor C4 and a diode 3, a signal is buffered to be input into the operational amplification voltage stabilizing circuit; an audion Q7 feeds back the signal to the same-phase input end of the operational amplifier AR2; finally, the operational amplification voltage stabilizing circuit applies an operational amplifier AR3 to carry out same-phase signal amplification; and meanwhile, an audion voltage stabilizing circuit formed by an audion Q8 and a voltage stabilizing pipe D10 is used for voltage stabilization to output. Data signal frequency can be converted into a compensation signal of the data signal of the portable meteorological measuring instrument, and meanwhile, the signal is automatically calibrated.

An embodiment of the invention discloses an automatic air-conditioner switching method and an automatic air-conditioner switching device. Two air conditioners alternating working can be adopted to effectively prevent service life of an air conditioner from being affected after the air conditioner is used for a long time. The switching method includes judging whether a main engine is in an operating state or not when automatic switching function is started; if the main engine is not in the operating state, then judging whether an auxiliary engine is in the operating state or not; if the main engine is in the operating state, then judging whether preset time is arrived or not; if the preset time is arrived, then closing the main engine and opening the auxiliary engine to operate; if the auxiliary engine is in the operating state, then judging whether preset time is arrived or not; and if the preset time is arrived, then closing the auxiliary engine and opening the main engine to operate. 485 chips are adopted as communication tools, so that the auxiliary engine operation can be preset to ensure that working frequency of the auxiliary engine is the same with the main engine, and problems that power rate of the auxiliary engine is limited in automatic controlling and switching methods of audion amplifying circuits in the prior art are solved.

The invention provides a picosecond single recurrent pulse transmitter. Picosecond single recurrent pulse signals are generated according to the switching characteristics of a radio frequency audion, the driving capacity of a broadband linear power amplifying audion, the phase step characteristics of a phase step recovery diode, the capacitance variable characteristics of a variable capacitance diode, the total reflection characteristics of a micro-strip short-circuit wire and the like, the output pulse positive and negative polarity symmetry is good, the peak-to-peak value amplitude is large, the pulse bottom width and trailing are small, and the picosecond single recurrent pulse transmitter is suitable for the high-resolution pulse type ultra wide band radar system application.

The invention relates to an alternating current power detection device for detecting the state of an alternating current power. The device comprises a detection circuit and a microprocessor; the detection circuit comprises a first voltage source, a first resistor and a photoelectric coupler with a bidirectional light emitting diode and a photosensitive audion; the live wire end of the alternating current power is connected with one end of the bidirectional light emitting diode; the zero wire end of the alternating current power is connected with the other end of the bidirectional light emitting diode; the emitting electrode of the photosensitive audion is earthed; the collecting electrode of the photosensitive audion is connected with an interruption pin of the microprocessor and a detection pin and is connected with the first voltage source through the first resistor; the output end of the microprocessor is used for connecting an electric appliance; a state signal of the alternating current power is provided for the microprocessor through a detection circuit and triggers an inner detection program of the microprocessor to carry out real-time analysis on the state of the alternating current power; and the output end of the microprocessor provides an analytic result for the electric appliance. The detection circuit is simple and low in cost.

The invention discloses a vehicle power supply time-delay device comprising a power converter system and a control circuit, wherein the anode of a diode D2 of the control circuit is connected with a power supply +24V, and the cathode of the diode D2 is connected with the anode of a capacitor CD2, one end of a resistor R4 and the emitting electrode of an audion Q3; the collecting electrode of the audion Q3 is connected with a stabilized-voltage integrated circuit, and the base electrode of the audion Q3 is connected with the other end of the resistor R4; one end of a resistor R3 is connected with the base electrode of the audion Q3, and the other end is connected with the collecting electrodes of an audion Q2 and an audion Q1; the emitting electrode of the audion Q1 is connected with the base electrode of the audion Q2; one end of a resistor R2 is connected with the base electrode of the audion Q1 and one end of a resistor R1; the other end of the resistor R1 is connected with the anode of a capacitor CD1 and the cathode of a diode D1; the anode of the diode D1 is connected with the vehicle power supply +24V; and the cathode of the capacitor CD2, the cathode of the capacitor CD1, the other end of the resistor R2 and the emitting electrode of the audion Q2 are all earthed.

The invention discloses an amplifier circuit of a three-level amplifying structure. The amplifier circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a first diode, a first audion, a second audion and a third audion. According to the amplifier circuit of the three-level amplifying structure, triple amplifying structure bodies are designed, the conversion rate of an amplifier is significantly improved, the design is ingenious, and the amplifier circuit is worthy of popularization.

The invention discloses a solenoid valve control circuit and a solenoid valve switch-in self-checking method thereof. The solenoid valve control circuit comprises a solenoid valve circuit and a voltage dividing and sampling circuit. The solenoid valve circuit comprises a microprocessor circuit, a solenoid valve DC, an audion Q1, a polar capacitor C1, a current limiting resistor R1 and a current limiting resistor R4, and the voltage dividing and sampling circuit comprises a divider resistor R2 and a sampling resistor R3. The analog-to-digital conversion input end of the microprocessor circuit is connected with one end of the sampling resistor R3. The solenoid valve switch-in self-checking method includes the following steps that a microprocessor U1 controls the audion Q1 to be disconnected, and the sampling voltage V1 of the sampling resistor R3 is collected; then the audion Q1 is controlled to be conducted and delayed, wherein the delay time is T1, and the sampling voltage V2 of the sampling resistor R3 is collected; and after that, the sampling voltage V1 is compared with the sampling voltage V2; if V1 is equal to V2, the solenoid valve is not switched in, otherwise, the solenoid valve is switched in. The solenoid valve control circuit has the advantages of scientific design and high safety, and the method occupies fewer resources of the system, is easy to realize, low in cost, simple and practical.

The invention provides a temperature compensation current reference circuit applied to an integrated circuit, wherein a sixth transistor, a seventh transistor and an eighth transistor are mutually matched current mirrors, and the proportion of the current mirrors is 1:1:1; a ninth transistor and a tenth transistor are mutually matched current mirrors, the proportion of the current mirrors is 1:1; a first transistor and a second transistor are mutually matched NPN triodes; a third transistor and a fourth transistor are mutually matched; and a first resistor utilizes a high-value polycrystal resistor, and a second resistor utilizes a P-type ion injection resistor. Positive temperature coefficient current and negative temperature coefficient current are added to obtain temperature compensation reference current, and then the temperature compensation reference current is provided for other circuits by utilizing the current mirrors. The temperature compensation current reference circuit applied to the integrated circuit, disclosed by the invention, has the advantages that the reference current changes very tiny in a certain temperature change range (minus 40-130 DEG C).

The invention discloses a dimmable LED constant-current output driving system based on a power amplifying circuit. The dimmable LED constant-current output driving system is characterized by mainly comprising a processing chip U, an audion VT2, a protective circuit, a low-pass filter circuit, a linear dimming circuit, a resistor R1, a capacitor C4 and a gate drive circuit, wherein the low-pass filter circuit is connected between the protective circuit and the processing chip U in series; the linear dimming circuit is connected between the protective circuit and the base of the audion VT2 in series; the resistor R1 is connected between the collector of the audion VT2 and the LD pin of the processing chip U in series; the anode of the capacitor C4 is connected with the emitter of the audion VT2; the cathode of the capacitor C4 is connected with the RI pin of the processing chip U; and the gate drive circuit is respectively connected with the GATE pin of the processing chip U and the low-pass filter circuit. According to the dimmable LED constant-current output driving system disclosed by the invention, the brightness of an LED can be adjusted according to requirements; compared with the traditional LED driving system, the dimmable LED constant-current output driving system disclosed by the invention has better linearity when the brightness of the LED is adjusted; therefore, the LED is steadier to work; and the flicker phenomenon can be avoided.

The invention discloses a remote turn-off control signal receiving circuit. The remote turn-off control signal receiving circuit comprises a remote control end, a voltage input end, a turn-off signal input end, an audion used for outputting the turn-off signals, a biasing circuit and a clamping circuit, a first capacitor which is used for discharging transient pulse energy, and a second capacitor which is used for absorbing the transient pulse energy. The first capacitor is connected between the remote control end and the voltage input end. The second capacitor is connected between a base electrode of the audion and the ground. The value of the second capacitor is set according to remote control (RC) time constant of a biasing resistor and the second capacitor. When the transient pulse occurs, through charging of the second capacitor, time that voltage of the two ends of the second capacitor reaches the break-over voltage of the audion is greater than the duration time of the transient pulse. The value of the first capacitor needs to be set according to the size of transient pulse energy. The remote turn-off control signal receiving circuit can restrain the transient pulse, prevent damage of devices, improve reliability of products, and can solve the problem of long time power down of pulse-width modulation (PWM) switch power supply output voltage.

The invention relates to a single chip microcomputer controlled power grid detection and reset circuit, which is characterized by comprising a micro-control circuit, a main control circuit and an audion circuit, wherein a PA1 detection port of the micro-control circuit is connected with a 12V power supply through the main control circuit to form a power grid power on / power failure detection structure, a PA4 of the micro-control circuit is used as an output port and is externally connected with an external interruption port of a main control chip of a main control chip circuit through electrical resistance, the micro-control circuit controls an audion to switch on / off, and an output end of the audion circuit forms the reset circuit for the main control circuit; a single chip microcomputer chip PA4 port of the micro-control circuit respectively starts and stops outputting a 200HZ square wave signal according to the power on and power failure of the PA1 port, so that the main control circuit can enter a normal or power-save working mode. The single chip microcomputer controlled power grid detection and reset circuit has the beneficial effects that the circuit is simple in structure, the used components are less, and the economic benefit is increased.

An overvoltage and undervoltage protective circuit based on a three-end adjustable shunt reference source comprises an undervoltage protective circuit, an overvoltage protective circuit and an output control circuit, wherein the undervoltage protective circuit, the overvoltage protective circuit and the output control circuit are connected in a power circuit, the undervoltage protective circuit is composed of a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2, an audion Q1, a voltage-regulator diode DZ1 and a TLV431 chip U1, the overvoltage protective circuit is composed of a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor 10, a capacitor C3, a capacitor C4, an audion Q2, a voltage-regulator diode DZ2, a voltage-regulator diode DZ3 and a TLV431 chip U2, and the output control circuit is composed of a resistor R11, a capacitor C5, an MOS transistor Q3 and a diode D1. According to the overvoltage and undervoltage protective circuit, the TLV431 is utilized as the standard, overvoltage and undervoltage protection can be conducted on a power supply, power consumption is low, accuracy is high and reaction speed is high.

A current inductive timer socket comprises: a principle relay circuit including an output relay and a voltage input terminal, a reed relay circuit including a capacitor, a plurality of diodes, a reed relay and a resistance, a counter circuit including a DC rectifier, seven series-connected counters, and a time select switch, a holding circuit including a neon light, a photodiode, an operational amplifier, a transistor, a diode and a resistance, a time switch circuit including three time switches, and three series-connected exciting transistors, and an inductive and amplification circuit including a transformer parallel-connected to a rated resistor, a set of two-stage operational amplifiers, a resistance, and a capacitor. When the electric appliance is in use, a signal of voltage drop produced at both ends of the rated resistor will be amplified by the operational amplifier and then transmitted to the counter circuit, making the counter circuit start to count automatically, and thus time operation is carried out.

The invention discloses a low power consumption power control circuit and method. The circuit comprises two NPN type audions Q1 and Q2, a P channel MOS tube Q3, a power source BT1, a power management chip U1 and a touch key S1. According to the circuit, a battery is adopted for supplying power, the touch key carries out triggering control over starting of the power source, the two NPN type audions Q1 and Q2 jointly control the grid of the P channel MOS tube Q3, and therefore the control purposes of low power consumption triggering starting and stopping according to needs are achieved. When the power source on a load needs to be turned off, the output level of the power management chip U1 is changed into a low level, the audion Q2 enters a cut-off state, the grid of the P channel MOS tube Q3 is at high potential, the MOS tube is in a cut-off state, loading loop power supply is cut off, the management chip enters a physical power down mode, and just weak leakage currents exist.

The invention discloses a tristate input circuit. In the circuit, the fact that bases and collectors of audions are in short circuit so as to have the characteristics of diodes is utilized, and one input end of two differential amplifiers is biased to two fixed voltages; the voltage D-value between the two fixed voltages is the conduction pressure drop Vbe of the diode; and the characteristic that the differential amplifiers are sensitive to a voltage difference is used to amplify the voltage D-value and output corresponding marking signals as well as detect that the input is in a high level, low level or suspension state, thus realizing the tristate input.

The invention discloses a photoelectric relay capable of discharging quickly, and belongs to the technical field of electronics. The photoelectric relay comprises an input end light-operated signal producing circuit, a light-operated signal receiving and photovoltaic conversing circuit, a control circuit and an output circuit. The input end light-operated signal producing circuit is composed of a light-emitting diode (LED) (11). The light-operated signal receiving and photovoltaic conversing circuit is composed of a photodiode array (PDA). The control circuit comprises a cascade audion and three diodes, and is used for providing a charge-discharge channel for power metal oxide semiconductor field effect transistor (MOSFET) components of the output circuit. The output circuit comprises a pair of power MOSFET components. According to the photoelectric relay capable of discharging quickly, cascade of two or a plurality of audions is adopted in the control circuit, current amplification times of the audions are amplified after cascade, and speed of extracting charges is accelerated obviously. Compared with an existing photoelectric relay, the photoelectric relay capable of discharging quickly is faster in discharging speed and can be applied to relay situations of higher frequency.

The invention discloses a bias circuit for a radio-frequency power amplifier. The bias circuit comprises a differential amplifier composed of two audions; the differential amplifier is that the bases of the two audions are used as differential input ends and the collector of one audion is used as a single output end; the bias circuit further comprises an active driving tube; the base of the active driving tube receives voltage of the single output end of the differential amplifier as input; the emitter of the active driving tube provides base bias current for a power tube; two voltage dividing branches respectively provide base voltage for the two audions forming the differential amplifier; and furthermore, when the temperature is changed, the change directions of the base voltage of the two audions forming the differential amplifier are opposite. By means of the bias circuit disclosed by the invention, the sensitivity to temperature change can be obviously reduced; the linearity of the radio-frequency power amplifier is improved; and thus, the radio-frequency power amplifier can keep a normal working state in a relatively severe working condition and environment.

The invention discloses a gain self-adaption error amplifier comprising a level shift circuit, an operation transconductance amplification circuit and a comparison circuit. An input level of the operation transconductance amplification circuit meets a normal operation requirement by the level shift circuit; the operation transconductance amplification circuit uses a bipolar audion as a differential pair transistor, and utilizes an MOS tube common-source structure current mirror to provide current bias for the differential pair transistor to reduce power consumption, so as to ensure providing of greater gain; the comparison circuit utilizes a feedback structure to control a circuit output slew rate, so as to output a control signal of the operation transconductance amplification circuit; an amplitude limiting circuit limits the output voltage of the operation transconductance amplification circuit. According to the amplifier provided by the invention, power output ripples in a load current stabilization application are reduced, and thus power consumption of a system is reduced, and meanwhile influence on a load transient behavior is small.

The invention relates to a full-bridge phase shift induction heating device, which comprises a main circuit for induction heating, a drive control circuit, a current-limiting protection and power regulation control circuit, an overcurrent protection circuit and a frequency tracking circuit, wherein the main circuit comprises four audions, four diodes, a power supply, an inductance, an electric resistance, a current transformer and a capacitance; the drive control circuit is used for outputting four PWM (Pulse-Width Modulation) pulse signals to drive the main circuit, and the four PWM pulse signals are respectively electrically connected to base electrodes of the four audions; the current-limiting protection and power regulation control circuit is electrically connected to the drive control circuit and is used for automatically regulating sizes of phase shift angles among the four audions so as to realize regulation of output power; the overcurrent protection circuit is electrically connected to the drive control circuit and is used for protecting heating power supply overcurrent or short trouble power supply of the full-bridge phase shift induction heating device; and the frequency tracking circuit is electrically connected to the drive control circuit and is used for enabling the frequency of the four PWM pulse signals sent by the drive control circuit and load current frequency of a resonant circuit in the frequency tracking circuit to be synchronized.