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

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 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.

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 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.