30results about How to "Few external components" patented technology

The present invention relates to a constant current and voltage controller carrying out pin multiplexing and a three-pin package for carrying out low-cost flyback converters. A flyback converter includes a controller integrated circuit (IC) housed in an IC package with only three terminals. An inexpensive TO-92 transistor package can be used. A switch terminal is coupled to an inductor switch that is turned on by a switch control signal having a frequency and a pulse width. The inductor switch controls the current that flows through a primary inductor of the flyback converter. The controller IC adjusts the frequency in a constant current mode such that output current remains constant and adjusts the pulse width in a constant voltage mode such that output voltage remains constant. A power terminal receives a feedback signal that is derived from a voltage across an auxiliary inductor of the flyback converter. The feedback signal provides power to the controller IC and is also used to generate the switch control signal. The controller IC is grounded through a ground terminal.

The invention discloses a radiofrequency power detection circuit. A resistor R1, a resistor R2, a resistor R3 and a first diode are orderly and serially connected between a power end VCC and the ground, a signal input end RFIN is connected to a node between the resistor R2 and the resistor R3 through a capacitor C1, the node is also connected with a base electrode of a triode Q2, a collector of the triode Q2 is connected to a node between the resistor R1 and the resistor R2, a second diode and a resistor R4 are orderly and serially connected between an emitter of the triode Q2 and the ground, a resistor R5 and a resistor R7 are orderly and serially connected between the emitter of the triode Q2 and a signal output end VOUT, a capacitor C2 is connected between a node (between the resistor R7 and the resistor R5) and the ground, and a resistor RL is connected between the signal output end VOUT and the ground. The radiofrequency power detection circuit sets a direct current operating point of a radiofrequency power detector, eliminates the limit of positive voltage of a rectifier diode, and increases the range of radiofrequency power detection; and the detection circuit can be integrated into an HBT power amplification chip, which reduces peripheral elements of a power amplifier and saves the area of a printed circuit board.

The invention provides a flyback power converter, which comprises a transformer, a first rectifier, a second rectifier, a first capacitor, a second capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a switch transistor and a pulse frequency modulation and a pulse width modulation controller, wherein the pulse frequency modulation and a pulse width modulation controller is used for providing a control signal to drive the grid of the switch transistor; the transformer comprises a primary winding, a secondary winding and an auxiliary winding; one end of the primary winding is connected with the power supply input end of the flyback power converter, and the other end of the primary winding is connected with the drain of the switch transistor; the switch transistor is used for controlling the voltage of the primary winding; one end of the secondary winding is grounded, and the other end of secondary winding is connected with the anode of the secondary rectifier; and one end of the auxiliary winding is grounded, and the other end of the auxiliary winding is connected with one end of the secondary resistor. The structure of the flayback power converter can be effectively simplified.

The invention relates to a leakage monitoring chip for a leakage protector. The leakage monitoring chip comprises a power voltage regulator circuit, a reference voltage generator and a latching output circuit, wherein the power voltage regulator circuit is used for providing working voltage for the reference voltage generator and the latching output circuit; the leakage monitoring chip further comprises a circuit structure and a first amplifying circuit and a second amplifying circuit which have the same performance; an input end of a first differential amplifier circuit is electrically connected with an input end of a second differential amplifier circuit, and the end is used as the public input end to connect with an external circuit; the other input end of the first differential amplifier circuit is connected with the external circuit; the other input end of the second differential amplifier circuit is connected with the external circuit; the output end of the first amplifying circuit and the output end of the second amplifying circuit are electrically connected with the input end of the latching output circuit respectively; the reference voltage generator circuit is used for respectively providing reference voltage for the input ends of the first differential amplifier circuit and the second differential amplifier circuit. The leakage monitoring chip provided by the invention has the advantages that the leakage faults of the main loop and the ground wire can be monitored synchronously; and the two fault action current can be adjusted randomly in the scope of national safety standards; the leakage monitoring chip works stably and reliably and the personal safety can be more effectively protected.

The invention discloses a cardiac sound amplifying circuit based on an MAX 4465 amplifier chip and an LM 386 amplifier chip, comprising a prime amplifying circuit and a post amplifying and filtering circuit. An acquiring and amplifying circuit consists of the MAX 4465 amplifier chip and the LM 386 amplifier chip, with a direct-current power supply of 5V for providing voltage to the whole circuit. The cardiac sound amplifying circuit completes acquisition and amplification of a cardiac sound signal by necessary filtering, can be flexibly transplanted to various application circuits with a high degree of modularization, realizes a monitoring function to the cardiac sound and can meet the design requirements on the traditional portable medical products.

The invention relates to an alternating current direct driving intelligent dimming LED (light emitting diode) energy saving street lamp, which comprises an input protection unit [1], a rectification unit [2], an alternating current direct driving controller [3], a photosensitive sensor [4], an intelligent dimming unit [5], an energy buffer unit [6] and an LED unit [7], wherein the alternating current direct driving controller drives different groups of LEDs to give out light according to the sizes of the instant values of the pulse voltage after the rectification; the intelligent dimming unit converts environment illumination detected by the photosensitive sensor into a digital signal, and judges whether the current state is a normal lamp turning-on state or a daytime maintenance detection turning-on state, so that whether the dimming curve needs to be called or not is determined. The alternating current direct driving intelligent dimming LED energy saving street lamp has the advantages that the alternating current direct driving controller is used; a large-volume filtering capacitor is not needed; the power factor and the efficiency are high; the heating quantity is small; the reliability is high; the energy buffer unit is used, so that the flickering phenomenon of the alternating current direct driving LEDs is overcome; the dimming can be performed according to the curve set by a program; the deep energy saving can be facilitated.

The invention belongs to the field of electronic technologies and low-frequency signal amplification, and relates to a high-performance hearing-aid made of discrete components. The hearing-aid comprises a direct current (DC) power supply, a sound wave signal conversion circuit, a preposed low-frequency amplification circuit, a volume regulation circuit and a power amplification circuit. The hearing-aid is characterized in that a PNP (Positive-Negative-Positive) triode VT3 in the power amplification circuit is connected to be an emitter output form, and a headset socket CZ with a normally open contact is connected to an output load loop of the PNP triode VT3. The hearing-aid can be made of the discrete components without special integrated circuit with higher cost. The invention has the characteristics of simple circuit structure, fewer peripheral elements, wide working voltage range, less static current and electricity consumption, little cross distortion, good tone quality, and the like. The output power of the hearing-aid can meet the requirements on people with poor hearing. The problems of high price, difficulty in popularization and the like of some brands of hearing-aids on the market are solved or overcome.

The present invention relates to a control circuit and related method for controlling the output voltage of a controllable switching power supply. The switching power supply includes a primary-side switch and a transformer with auxiliary windings. After the primary-side switch is turned on, an auxiliary voltage that reflects the output voltage is induced in the auxiliary winding. The induced voltage is input to the control circuit as a control variable. In order to provide a control circuit that requires as few external components as possible, can be manufactured at low cost and requires as little space as possible, the driver output of the control circuit is connected to the control input of the primary side switch, the control circuit is designed as The switching frequency of the primary-side switch is adjusted by the auxiliary voltage, wherein the correlation constant factor between the switching frequency and the auxiliary voltage is selected, so that the output current of the switching power supply selects a preset value, and the driver output terminal is also connected to the comparator input to determine the current through this primary side switch.

The invention relates to a leakage monitoring chip for a leakage protector. The leakage monitoring chip comprises a power voltage regulator circuit, a reference voltage generator and a latching output circuit, wherein the power voltage regulator circuit is used for providing working voltage for the reference voltage generator and the latching output circuit; the leakage monitoring chip further comprises a circuit structure and a first amplifying circuit and a second amplifying circuit which have the same performance; an input end of a first differential amplifier circuit is electrically connected with an input end of a second differential amplifier circuit, and the end is used as the public input end to connect with an external circuit; the other input end of the first differential amplifier circuit is connected with the external circuit; the other input end of the second differential amplifier circuit is connected with the external circuit; the output end of the first amplifying circuit and the output end of the second amplifying circuit are electrically connected with the input end of the latching output circuit respectively; the reference voltage generator circuit is used for respectively providing reference voltage for the input ends of the first differential amplifier circuit and the second differential amplifier circuit. The leakage monitoring chip provided by the invention has the advantages that the leakage faults of the main loop and the ground wire can be monitored synchronously; and the two fault action current can be adjusted randomly in the scope of national safety standards; the leakage monitoring chip works stably and reliably and the personal safety can be more effectively protected.

The invention discloses a self-powered CMOS piezoelectric vibration energy harvester. The self-powered CMOS piezoelectric vibration energy harvester is characterized in that the self-powered CMOS piezoelectric vibration energy harvester includes a CMOS piezoelectric synchronous charge extraction and collection interface circuit and a follow current energy storage circuit; the CMOS piezoelectric synchronous charge extraction and collection interface circuit is encapsulated in the form of an integrated circuit form; the CMOS piezoelectric synchronous charge extraction and collection interface circuit is provided with a first detection circuit output control interface, a second detection circuit output control interface, a first piezoelectric element connection interface, a second piezoelectric element connection interface, a first capacitance detection interface, a second capacitance detection interface, an external-connection inductance interface and a grounding port; the CMOS piezoelectric synchronous charge extraction and collection interface circuit includes a positive extremum detection module, a negative extremum detection module, a positive and negative extremum interlock switch, a positive and negative direction vibration automatic switching switch and a dynamic substrate level selection module. The self-powered CMOS piezoelectric vibration energy harvester has the advantages of easiness in integration, small circuit size, low power consumption and high energy extraction efficiency; and a self-powered design is adopted, so that the self-powered CMOS piezoelectric vibration energy harvester further has the advantage of no need for an external power source.

The invention belongs to the technical field of electronics and audio amplification, and relates to a hearing-aid made of a TDA2822 (Tunnel Diode Amplifier). The hearing-aid comprises a direct current (DC) power supply, a power supply filter circuit, a constant current source and pickup circuit, an emitter follower, an audio signal regulating circuit and an integrated power amplification circuit. The hearing-aid is characterized in that the constant current source and pickup circuit is used as a power supply of a capacitor microphone (MIC), the emitter follower is used as a high-resistance amplification circuit, and the type of the integrated power amplification circuit (IC1) in a BTL (Bridge-Tied-load) mode application circuit is TDA2822M. The hearing-aid provided by the invention is formed by combining discrete components and the integrated power amplification circuit. The hearing-aid has the characteristics of simple circuit structure, fewer peripheral elements, little cross distortion, good tone quality, wide working voltage range, less static current and electricity consumption, output power capable of meeting the requirements on people with poor hearing, and the like, and is a hearing-aid attractive in price and quality, thereby solving or overcoming the problems of partial defects existing in some hearing-aids on the market, and the like.

The invention discloses an output-power-adjustable direct-current inverter. The direct-current inverter consists of a 12V direct-current power supply, a multi-vibrator circuit, a pulse width modulating circuit, a voltage comparison circuit, a push-pull power amplifying circuit, a booster circuit and a rectangular wave voltage shaping circuit, and is characterized in that the model of a pulse width modulation oscillation circuit IC1 in the multi-vibrator circuit is SG3524. The direct-current inverter is a standby power supply which is independent of a commercial power grid. The output-power-adjustable direct-current inverter disclosed by the invention is suitable for equipment such as general illuminating equipment, computers and electronic instruments, can be taken as a temporary emergency power supply for use during short-time power failure of a power supply circuit, and is suitable for emergency illumination or fire-fighting emergency power supplies at various public places. The output-power-adjustable direct-current inverter has the characteristics of simple circuit structure, small quantity of peripheral elements, high conversion efficiency, small temperature rise in a rated power range, output power being up to 400W, and adjustability of the output power of the inverter by modulating the pulse width through an external potentiometer.

The invention relates to a multi-channel active protection control system for an industrial-boiler pulverized coal storage and supply system. The multi-channel active protection control system comprises a sequential generator, a function generator, a square-wave generator, an output channel selector and a digital signal output unit; the output bit of the sequential generator is stared and stoppedbit by bit in accordance with the specified timing sequence through the sequential generator according to time cycle requirements and work sequence requirements; an input signal of the function generator is a duty ratio of the current load to the standard, the output control duty ratio is transmitted to the square-wave generator through multiplication, and the square-wave generator is used for adjusting and controlling the jetting working time and the jetting suspend time in the jetting cycle of compressed air and inert gas in the pulverized coal storage and supply system; the output channel selector receives the square-wave sequence from the sequential generator and the square-wave with the adjustable duty ratio; and the digital signal output unit is an external output channel of the control system. The multi-channel active protection control system can be highly integrated with a boiler thermal control system and reduce the number of field hardware controllers.

The invention relates to a singlechip based digital tuning frequency modulation (FM) radio. The radio comprises a control module, an FM module, a display module, a power supply module and a power amplifier module. The singlechip based digital tuning FM radio adopts a TEA5767 chip of PHILIPS. Conventional FM radios have a large circuit volume, are inconvenient in tuning and have poor stability. The singlechip based digital tuning FM radio overcomes the defects. The FM module adopts the TEA5767 chip of PHILIPS, which has the advantages of having few external elements and low cost and realizing functions of the FM radio. The radio mainly comprises the TEA5767 frequency modulation chip and an STC89C52 microcontroller, processes the signal received by the frequency modulation chip and displays the signal on a liquid crystal display (LCD) by combining the display module, the power amplifier module, a keyboard and the power supply module. Then the design of the FM radio is completed.

A generator voltage regulator for constant-frequency trigger excitation, comprising: a transistor array integrated chip 3, including four crystal groups, respectively used to form a fixed-frequency oscillation circuit, a pulse shaping circuit, and a power trigger circuit; a fixed-frequency oscillation resistance-capacitance circuit The component part 2 forms a fixed-frequency oscillation circuit with two crystal groups; the power unit 5, the feedback unit 6, and the feedback unit is connected to the output terminal of the power unit and the input terminal of the third crystal group to form a power trigger circuit; the freewheeling unit 7, Used to provide a continuous current path; the sampling unit 1 is used to sample the output voltage; the threshold unit 4 is connected to the sampling unit and the third crystal group to provide a reference value; the output terminal of the fixed frequency oscillation circuit is connected to the fourth crystal through a capacitor The group input terminals are connected to form a pulse shaping circuit, and the fixed frequency triggers the power trigger circuit to set it to turn on the excitation current. When the output voltage of the generator is greater than the set value, the sampling voltage triggers the power trigger circuit through the threshold unit to reset and cut off the excitation. current.

The invention discloses a high-integration control chip and a power supply circuit with the same. The high-integration control chip comprises a switching tube, a driving module, a primary constant-voltage control module and a slope compensation module. The primary constant-voltage control module is connected with a primary side voltage feedback end of a switching power supply and the driving module, and constant-voltage control processing is carried out on feedback voltage of the primary side voltage feedback end of the switching power supply. The slope compensation module is respectively connected with the primary side voltage feedback end of the switching power supply and the primary constant voltage control module. Slope compensation processing of the output voltage is carried out according to the primary side voltage feedback value, so that the switching power supply circuit outputs a voltage value with a set slope. Therefore, the voltage and current slope requirements of battery charging and motor driving can be met. The power supply circuit adopts a primary side feedback mode, so that peripheral circuits such as feedback optocouplers can be reduced, and peripheral elements ofthe circuit are reduced.

The invention provides a flyback power converter, which comprises a transformer, a first rectifier, a second rectifier, a first capacitor, a second capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a switch transistor and a pulse frequency modulation and a pulse width modulation controller, wherein the pulse frequency modulation and a pulse width modulation controller is used for providing a control signal to drive the grid of the switch transistor; the transformer comprises a primary winding, a secondary winding and an auxiliary winding; one end of the primary winding is connected with the power supply input end of the flyback power converter, and the other end of the primary winding is connected with the drain of the switch transistor; the switch transistor is used for controlling the voltage of the primary winding; one end of the secondary winding is grounded, and the other end of secondary winding is connected with the anode of the secondary rectifier; and one end of the auxiliary winding is grounded, and the other end of the auxiliary winding is connected with one end of the secondary resistor. The structure of the flayback power converter can be effectively simplified.

The invention discloses a power amplifying circuit based on an LM3886 chip. The specific circuit design includes the LM3886 chip, and also includes first to ninth resistors and first to eighth capacitors connected to the LM3886 chip. The present invention can also superimpose the operation amplifier NE5532 chip or the AD827 chip as the front linear amplifier circuit and the tone amplifier circuit. The circuit design adopted in the present invention has high output power, small distortion, complete protection functions, few peripheral components, easy fabrication and debugging, and stable and reliable operation. The power amplifying circuit has the characteristics of simplicity and applicability.

The invention relates to a fast and stable AGC amplifier, belonging to the technical field of signal amplification, comprising a front-stage VGA amplifier circuit (1), a rear-stage VGA amplifier circuit (2), a continuous detection logarithmic amplifier circuit (3) and a voltage dividing circuit (4 ); the front-stage VGA amplifier circuit (1) is connected in series with the rear-stage VGA amplifier circuit (2); the signal input end of the continuous detection logarithmic amplifier circuit (3) is connected to the signal input end of the front-stage VGA amplifier circuit (1), divided The input end of the pressure circuit (4) is connected to the output end of the continuous detection logarithmic amplifier circuit (3), and the output end of the voltage divider circuit (4) is connected to the front stage VGA amplifier circuit (1) and the rear stage VGA amplifier circuit (2). Control terminal Vagc. The amplitude of the output signal of the invention can be kept stable quickly, and the stabilization time is less than 2 μs, which is less than one-thousandth of the stabilization time of the traditional AGC amplifier. Moreover, the entire circuit of the present invention has a simple structure and no discrete devices, so the consistency between the circuits is very good, basically no debugging is required, and it is convenient for mass production.

The invention relates to a control circuit and a related method for controlling the output voltage of a controllable switching power supply. The switching power supply includes a primary-side switch and a transformer with an auxiliary winding. After the primary-side switch is turned on, an auxiliary voltage reflecting the output voltage is induced in the auxiliary winding. The induced voltage is input to the control circuit as a control variable. In order to provide a control circuit that requires as few external components as possible, can be manufactured at low cost, and requires as little space as possible, the driver output of the control circuit is connected to the control input of the primary-side switch, the control circuit is designed as Relying on the auxiliary voltage to adjust the switching frequency of the primary-side switch, wherein the correlation constant factor between the switching frequency and the auxiliary voltage is selected so that the output current of the switching power supply selects a preset value, and the output terminal of the driver is also directly connected to a comparison input to the primary-side switch to determine the current through the primary-side switch.

The invention discloses a control circuit for an intelligent and mobile explosionproof charging box of an unmanned aerial vehicle. The control circuit comprises a main charging loop and a control charging circuit, wherein the main charging loop comprises a DCDC interface and a main current detection circuit which are sequentially connected, the main current detection circuit is connected to eightnon-isolation synchronous buck modules after shunting, the eight non-isolation synchronous buck modules are respectively connected to six charging terminals, a USB charging interface and a remote controller interface, the control charging circuit comprises a master control circuit and three groups of sub-control charging circuits, the three groups of sub-control charging circuits are all connectedto the master control circuit, the three groups of sub-control charging circuits and the master control circuit are connected to the eight non-isolation synchronous buck modules in front of the six charging terminals, the USB charging interface and the remote controller interface, and two of the non-isolation synchronous buck modules are controlled by each group of sub-control charging circuit and the master control circuit. By the control circuit, charging of an unmanned aerial vehicle battery can be achieved; and by a modular structure, the processing speed and the processing real-time performance of the whole circuit can be ensured.

The invention provides a tripolar disconnection leakage protection plug, and belongs to the technical field of low-voltage power distribution protection devices. The tripolar disconnection leakage protection plug comprises a tripping circuit, a first zero sequence current transformer, a second zero sequence current transformer and a driving circuit, wherein the driving circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a diode, a thyristor and a driving chip, the seventh pin of the driving chip is connected with one end of a secondary coil of the second zero sequence current transformer, the sixth pin of the driving chip is connected with the other end of the secondary coil of the second zero sequence current transformer through the second resistor, the second pin of the driving chip is connected with one end of the secondary coil of the first zero sequence current transformer, and the first pin of the driving chip is connected with the other end of the secondary coil of the first zero sequence current transformer through the third resistor. The tripolar disconnection leakage protection plug has the advantages that the peripheral devices of the driving chip can be greatly reduced, no action or wrong action can be eliminated, and the use reliability is guaranteed.

The invention discloses a circuit of a self-excited oscillation voltage-multiplying and constant-current control electromagnetic valve and a gas stove using the same. The circuit of the self-excited oscillation voltage-multiplying and constant-current control electromagnetic valve comprises a self-excited oscillation module for generating a PWM signal, a full-wave rectification module for outputting a voltage-multiplying driving voltage according to the PWM signal, and a negative feedback amplification module for outputting a negative feedback constant current according to the voltage-multiplying driving voltage to control the electromagnetic valve. According to the circuit of the self-excited oscillation voltage-multiplying and constant-current control electromagnetic valve, the self-excited oscillation module generates a PWM signal, and then the full-wave rectification module outputs a voltage-multiplying driving voltage according to the PWM signal of the self-excited oscillation module, and finally, the electromagnetic valve is controlled by the negative feedback amplification module according to the voltage-multiplying driving voltage negative feedback constant-current output of the full-wave rectification module, so that the stable output of the electromagnetic valve is realized by adopting a self-excited oscillation voltage-multiplying and constant-current control mode, the control of a switching power supply chip is abandoned, peripheral components are reduced, the hardware cost in the design process is reduced, and therefore, stable gas injection of the gas stove isrealized.

The invention relates to a hearing aid made from a monolithic integrated circuit. The hearing aid made from the monolithic integrated circuit consists of a 3V direct current power supply, a sound pickup circuit, an emitter follower, an audio signal regulating circuit and a bridge-tied-load (BTL) mode amplifying circuit, wherein the model of an integrated power amplifying circuit IC1 used in the BTL mode amplifying circuit is TDA2822M. The hearing aid made from the monolithic integrated circuit is combined by discrete elements and the integrated power amplifying circuit. The invention has the characteristics that: the hearing aid has a simple circuit structure, few peripheral elements, low cross distortion, high sound quality, low working voltage and low power consumption of quiescent current, the output power can completely meet the requirements of persons having hearing impairments, and the like, the hearing aid is a hearing aid which has high quality and low price, and the problems that some hearing aids have certain defects in the market and the like are solved.

A flyback converter includes a controller integrated circuit (IC) housed in an IC package with only three terminals. An inexpensive TO-92 transistor package can be used. A switch terminal is coupled to an inductor switch that is turned on by a switch control signal having a frequency and a pulse width. The inductor switch controls the current that flows through a primary inductor of the flyback converter. The controller IC adjusts the frequency in a constant current mode such that output current remains constant and adjusts the pulse width in a constant voltage mode such that output voltage remains constant. A power terminal receives a feedback signal that is derived from a voltage across an auxiliary inductor of the flyback converter. The feedback signal provides power to the controller IC and is also used to generate the switch control signal. The controller IC is grounded through a ground terminal.

The invention discloses a radiofrequency power detection circuit. A resistor R1, a resistor R2, a resistor R3 and a first diode are orderly and serially connected between a power end VCC and the ground, a signal input end RFIN is connected to a node between the resistor R2 and the resistor R3 through a capacitor C1, the node is also connected with a base electrode of a triode Q2, a collector of the triode Q2 is connected to a node between the resistor R1 and the resistor R2, a second diode and a resistor R4 are orderly and serially connected between an emitter of the triode Q2 and the ground,a resistor R5 and a resistor R7 are orderly and serially connected between the emitter of the triode Q2 and a signal output end VOUT, a capacitor C2 is connected between a node (between the resistor R7 and the resistor R5) and the ground, and a resistor RL is connected between the signal output end VOUT and the ground. The radiofrequency power detection circuit sets a direct current operating point of a radiofrequency power detector, eliminates the limit of positive voltage of a rectifier diode, and increases the range of radiofrequency power detection; and the detection circuit can be integrated into an HBT power amplification chip, which reduces peripheral elements of a power amplifier and saves the area of a printed circuit board.

The invention discloses an RS-485 interface chip with an automatic transceiving function and a control method of the RS-485 interface chip, and belongs to the technical field of communication circuits. The RS-485 interface chip with the automatic transceiving function comprises an RS-485 chip and a control signal recognition circuit arranged in the RS-485 chip; the control signal recognition circuit is connected with the driver input end of the RS-485 chip and a stae machine arranged in the RS-485 chip. Accordingly, the problems that in the related technique, an RS-485 chip can achieve the automatic transceiving function only by being connected with a peripheral circuit and is weak in driving capacity, and the data transmission speed of the RS-485 chip is limited are solved, and the advantages that the automatic transceiving function can be achieved without the peripheral circuit, the transmission speed is not limited, external elements are reduced, and miniaturization design of the equipment is promoted are achieved.

The invention discloses a wireless endoscope system with a multipoint networking function, and relates to the technical field of medical instruments, the wireless endoscope system comprises a wireless endoscope host, a wireless receiving end, a display device and an intelligent control device, the wireless endoscope host comprises a detachable cold light source and a wireless RF radio frequency transmission module, the wireless endoscope host supplies power to the detachable cold light source, the detachable cold light source provides illumination for the whole wireless endoscope host, the wireless endoscope host is connected with the wireless receiving end through the wireless RF transmission module, the wireless receiving end is connected with the intelligent control device through a signal line, and the intelligent control device is connected with the detachable cold light source. The wireless receiving end is connected with a plurality of intelligent control devices through wifi signals. According to the wireless endoscope system, control and adjustment signals for functional parameters and the like of the wireless endoscope host can be sent, the high-speed local area network networking technology is achieved, the wireless endoscope system can be intelligentized, and doctors can watch operation pictures and function operation of endoscope equipment conveniently.

The invention relates to a multi-channel active protection control system for an industrial-boiler pulverized coal storage and supply system. The multi-channel active protection control system comprises a sequential generator, a function generator, a square-wave generator, an output channel selector and a digital signal output unit; the output bit of the sequential generator is stared and stoppedbit by bit in accordance with the specified timing sequence through the sequential generator according to time cycle requirements and work sequence requirements; an input signal of the function generator is a duty ratio of the current load to the standard, the output control duty ratio is transmitted to the square-wave generator through multiplication, and the square-wave generator is used for adjusting and controlling the jetting working time and the jetting suspend time in the jetting cycle of compressed air and inert gas in the pulverized coal storage and supply system; the output channel selector receives the square-wave sequence from the sequential generator and the square-wave with the adjustable duty ratio; and the digital signal output unit is an external output channel of the control system. The multi-channel active protection control system can be highly integrated with a boiler thermal control system and reduce the number of field hardware controllers.

The invention discloses a cardiac sound amplifying circuit based on an MAX 4465 amplifier chip and an LM 386 amplifier chip, comprising a prime amplifying circuit and a post amplifying and filtering circuit. An acquiring and amplifying circuit consists of the MAX 4465 amplifier chip and the LM 386 amplifier chip, with a direct-current power supply of 5V for providing voltage to the whole circuit.The cardiac sound amplifying circuit completes acquisition and amplification of a cardiac sound signal by necessary filtering, can be flexibly transplanted to various application circuits with a highdegree of modularization, realizes a monitoring function to the cardiac sound and can meet the design requirements on the traditional portable medical products.