1065 results about "Voltage-regulator tube" patented technology

A protection circuit for use with a charger and a chargeable element, such as a rechargeable lithium ion battery, comprises a shunt regulator having a threshold ON voltage coupled in parallel across the chargeable element, and a temperature-dependent resistor, e.g., a positive temperature coefficient device, coupled in series between the charger and the chargeable element. The temperature dependent resistor is thermally and electrically coupled to the shunt regulator, wherein the first variable resistor limits current flowing through the shunt regulator if the current reaches a predetermined level less than that which would cause failure of the regulator, due to ohmic heating of the regulator.

The invention relates to an LED drive circuit of a source driver with the change of the output voltage and the induction quantity keeping constant current, which comprises a resistor R1, a voltage stabilizing tube, a capacitor, a flywheel diode D1 and an inductor and also comprises a first MOS transistor, wherein a grid electrode is connected with the negative pole of the voltage stabilizing tube, a drain electrode is connected between the inductor and the D1, a source electrode is connected with the positive pole of a current feed diode D2, and the negative pole of the D2 is connected with the negative pole of the voltage stabilizing tube; the source electrode drives a control circuit, and the control circuit comprises a second transistor, an RS trigger, a comparator and an inductive current zero-crossing detector. When the inductive current zero-crossing detector detects that inductive current crosses zero, the inductive current zero-crossing detector generates a setting signal and outputs the signal to the S input end of the RS trigger, so the second transistor is conducted; when output current is increased to enable the voltage of the positive input end of the comparator to be equal to reference voltage, the comparator turns over and controls the second transistor to be closed. According to the drive circuit, the output current is free from the influence of the induction quantity and the output voltage, the stability is enhanced, and the complexity and the cost of the circuit are lowered.

The present invention reveals a semiconductor chip structure and its application circuit network, wherein the switching voltage regulator or converter is integrated with a semiconductor chip by chip fabrication methods, so that the semiconductor chip has the ability to regulate voltage within a specific voltage range. Therefore, when many electrical devices of different working voltages are placed on a Printed Circuit Board (PCB), only a certain number of semiconductor chips need to be constructed. Originally, in order to account for the different demands in voltage, power supply units of different output voltages, or a variety of voltage regulators need to be added. However, using the built-in voltage regulator or converter, the voltage range can be immediately adjusted to that which is needed. This improvement allows for easier control of electrical devices of different working voltages and decreases response time of electrical devices.

The invention discloses a bidirectional dual-channel transient voltage suppressor (TVS), which comprises a P+ substrate layer, wherein a first N+ buried layer, a first P- epitaxial region, a second P- epitaxial region, a third P- epitaxial region and a second N+ buried layer are sequentially arranged on the P+ substrate layer from left to right; a first N injection region and a second N injection region are arranged on the first N+ buried layer and the second N+ buried layer respectively; a first N+ active injection region and a second N+ active injection region are arranged on the first P- epitaxial region and the third P- epitaxial region respectively; and a first P+ active injection region, a second P+ active injection region and a third P+ active injection region are arranged on the first N injection region, the second P- epitaxial region and the second N injection region respectively. Due to the adoption of a combined structure of a Zener voltage-regulator tube and a low-capacitance diode, the parasitic capacitance of the TVS is further reduced, on resistance is reduced, and the clamp characteristic of the TVS is improved; and the TVS can be widely applied to static electricity protection of certain portable equipment and high-speed interfaces.

An anti-noise-interference high-voltage side gate driving circuit comprises a high-voltage level shifting circuit, an RS latch and a driver, the high-voltage level shifting circuit converts the two input low-voltage pulse signals into two high-voltage pulse signals to be output, the two high-voltage pulse signals are respectively processed and then enter the RS latch, the RS latch outputs the signals into the driver, and the driver outputs a driving signal to control an external power tube be to switched on and off. According to the anti-noise-interference high-voltage side gate driving circuit, the high-voltage level shifting circuit is improved, the improved high-voltage level shifting circuit comprises two completely-same independent parts, and each independent part comprises two LDMOSs, a delay unit, a Zener voltage regulator tube, a capacitor, a resistor and a middle-voltage PMOS. The circuit can remove d(i)V(/i)/dt interference noise and differential mode noise, the transmission of normal signals is not affected while the noise interference is removed, and meanwhile the allowable negative VS voltages are increased.

The invention discloses a power switch device pulse transformer isolation driving circuit. The power switch device pulse transformer isolation driving circuit comprises a primary-side circuit, a pulse transformer Tr and a secondary-side circuit, wherein the primary-side circuit comprises an NPN transistor Q2, a PNP transistor Q3 and a blocking capacitor C1, and the secondary-side circuit comprises a power switch device Q1, a driving resistor Rg, a gate discharge resistor Rs, a diode D1, a compensation capacitor C2, a voltage-regulator tube Z1 and a negative pressure holding capacitor C3. The power switch device pulse transformer isolation driving circuit of the invention can be applied to all switching converters such as a boost converter, a buck converter, a forward converter, a flyback converter, a half-bridge switching converter, a half-bridge converter, a full-bridge converter and a push-pull converter, and can effectively improve the reliability of the switching converters.

The invention relates to a voltage buffer circuit used in a linear voltage regulator. The circuit consists of a basic voltage buffer circuit, an output current monitoring circuit and a current mirror circuit; wherein the input end of the basic voltage buffer circuit is connected with the output end of a voltage difference amplifier of the linear voltage regulator which is also the output of a dynamic bias power source buffer circuit; the output end of the output current monitoring circuit is connected with the input end of the current mirror circuit; the output end of the current mirror circuit is in parallel connection with a static bias current source. Under the condition that the static power loss of voltage regulator circuit is not increased, the impact of a pole of the output end of the voltage buffer circuit to system phase margin and stability is reduced; the invention doesn't need the traditional linear voltage regulator and utilizes an outer wave filtering capacitance equivalent series resistance to generate zero point, which lowers the system cost, reduces use difficulty and reduces the impact of the equivalent series resistance to the transient state response and noise restraint capacity of the voltage regulator circuit; a chip upper frequency compensation capacitance is not needed, which saves chip area.

The invention discloses a redundant energy acquiring circuit for a power module. The power module comprises at least one power semiconductor device, a first capacitor C1 and a first bypass switch K1.The redundant energy acquiring circuit provided by the invention comprises a first Zener diode VD1, a second Zener diode VD2, a second switch K2, a first resistor R1, a second resistor R2, a second capacitor C2, a power supply board card and a control board card. The power supply board card acquires energy form the capacitor C1, supplies power for the control board card and charges the capacitor C2. The control board card controls the first bypass switch K1 to be switched on by triggering the switch K1. According to the scheme provided by the invention, when a fault occurs in the power supplyboard card, the capacitor C2 is charged through utilization of a breakdown characteristic of the first Zener diode, and a triggering command is provided for the switch K2 through utilization of the breakdown characteristic of the second Zener diode. The reliable bypass of the bypass switch is realized under the condition that the fault occurs in the power supply board card. The device running stopunder the condition that the fault occurs in the power supply board card of the power module is avoided. The scheme cost is low. The reliability is high.

The invention relates to an LDO (Low Drop-out voltage regulator) overshooting protection circuit. The LDO overshooting protection circuit comprises a first MOS (Metal Oxide Semiconductor) tube, a second MOS tube, an error amplifier and a signal processing circuit, wherein the first MOS tube is controllably connected between an input end and an output end and is used for providing driving current to the output end; the second MOS tube is controllably connected between the input end and a grid electrode of the first MOS tube in parallel under the action of an enabled control signal; the error amplifier is used for carrying out comparing amplification on a voltage feedback signal sampled from the output end and standard voltage under the action of the enabled control signal; the output end of the error amplifier is connected with a control end of the first MOS tube; and the signal processing circuit is used for generating the enabled control signal under the action of an external enabled control signal and a detection signal obtained by detecting the size of voltage accessed into the input end. By reasonably controlling a sequential starting process of each module in an LDO electrifying process and overshooting protection can be provided for an externally hung large-capacitor type LDO with large current output or a capacitor-free LDO in a relatively wide power supply electrifying time range.

The invention provides an alternating-current direct-current adaptive switching value collecting circuit and method, relating to the technical field of electric power automation and used for facilitating software maintenance and reducing hardware cost. The circuit comprises a CPU (Central Processing Unit), a CPU side power supply, an auxiliary power supply, an auxiliary power supply signal input loop and a switching value signal input loop; the switching value signal input loop comprises a switching value isolating opto-coupler, a switching value limit resistor, a switching value voltage-regulator tube and a switching value output switch arranged in a collecting field, the switching value signal input loop is used for collecting switching value signals output by the switching value output switch; the auxiliary power supply signal input loop comprises an auxiliary signal isolating opto-coupler, an auxiliary signal limit resistor and an auxiliary signal voltage-regulator tube and is used for collecting auxiliary signals output by the auxiliary power supply, wherein the resistance value of the auxiliary signal limit resistor is larger than that of the switch limit resistor. The collecting circuit and method provided by the invention have the advantage of low hardware cost and convenience for software maintenance.

Compensation circuitry includes a resistor and transistor coupled in series with a reference current source to generate a variable reference voltage that is provided, via a voltage regulator, to bias elements of a core circuit in order to establish an operating current in the core circuit. In one embodiment, the resistor and transistor of the compensation circuitry are of similar construction to the bias elements of the core circuit, such that fluctuations in the ratio of the reference current and the operating current of the core circuit are minimized over process, supply voltage and temperature variations. The voltage regulator may be a low dropout regulator. In various embodiments, the core circuit may comprise a resistor biased voltage controlled oscillator, a differential current mode logic (CML) input to single CMOS output circuit, or like circuitry that may be sensitive to phase noise or requires low power operation.

The invention belongs to the technical field of engine electronic control, in particular relates to a battery jar voltage insulation test circuit based on a linear optical coupler. The circuit utilizes the double-output linear optical coupler, connects the input of the double-output linear optical coupler with one output to form a feedback amplifying element and accurately measures a battery jar power supply in an isolation condition by utilizing the characteristic that the current of two output ends of the double-output linear optical coupler is same; a battery jar voltage passes by a diode D1 capable of resisting reverse connection to form a stable voltage Uz by a current-limiting resistor R1 and a voltage regulator tube Z13, and the stable voltage Uz provides an amplifier U1A with a power supply and provides the output end of a linear photoelectric coupled device U2 with a current source. The invention has the advantage that a system has a wide suitable voltage range; the output stage of the circuit is powered by a subsequent modulus circuit power supply, and the circuit outputs in a similar drain open mode of a triode circuit so as to be simple to be matched with a system interface and effectively prevent the overpressure output of the circuit.

This invention relates to a DC voltage switch volume input state judgment module including a first resistor and light couple of judgment result signals output from the back end and a pre-triode, among which, the first resistor is connected with the light couple front end positive which negative is linked to the collector of the pre-triode which emitting pole is connected to the earth via the emitting pole, the base of which is linked to a base resistor, a serial VR-tube and a divider resistor between the DC voltage signal input end and the base resistor connecting with the divider to the earth via another parallel VR-tube and a current limiting resistor.

The invention discloses a self-calibration harmonic current transformer based on a gapped iron core coil. The transformer can output digital quantity and voltage simulation quantity which are linearly proportional to primary current containing harmonics, and can achieve the purposes of measurement and protection. The self-calibration harmonic current transformer comprises a gapped iron core, a primary coil, a measurement secondary coil, a protection secondary coil, a calibration coil, a monitoring secondary coil, an annular shielding box with a slotted inner ring, a first resistor, a second resistor, a third resistor, a sampling resistor, a first operational amplifier, a second operational amplifier, a third operational amplifier, a fourth operational amplifier, a first bidirectional voltage regulator tube, a second bidirectional voltage regulator tube, a third bidirectional voltage regulator tube, a fourth bidirectional voltage regulator tube, a signal conditioning circuit, an analog-to-digital converter, a microprocessor, a digital-to-analog conversion circuit, a calibration current drive circuit, a communication interface, and a first integral summation circuit and a second integral summation circuit which use a lossy integrator.

The invention discloses an LED bypass control circuit which comprises a detecting circuit, a switch and a capacitor. The detecting circuit is coupled to both ends of a target LED and used for detecting the state of the LED; and a bypass switch is connected in parallel with the LED and selectively conducted according to an output signal of the detecting circuit to bypass the LED. In the invention,the conducting state of the switch is maintained for a certain time through the capacitor, the LED bypass control circuit has lower power consumption compared with a traditional voltage-stabilizing tube bypass element, and meanwhile, an LED system can automatically restore the normal working state when in false triggering.

A device for measuring the current flowing through a power transistor of a voltage regulator, the voltage regulator having an input voltage and providing a regulated output voltage and the power transistor coupled between the input and output voltages. The measuring device includes a further transistor adapted to mirror a portion of the current flowing through the power transistor, the further transistor and the power transistor have a first non-drivable terminal in common that is coupled to the input voltage. The measuring device also includes a circuit block to connect the second non-drivable terminals of the power and the further transistor and to provide an output current equal to the portion of the current flowing through the first transistor; the measuring device further including a circuit adapted to detect the output current of said circuit block.

The invention discloses a circuit carrying out temperature compensation on the bias voltage of an avalanche photodiode, comprising a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a potentiometer, a negative temperature coefficient thermosensitive resistor, a voltage-regulator tube, a first crystal triode and a second crystal triode. In the circuit, a thermosensitive resistor feedback sampling part is formed by the first resistor, the second resistor, the potentiometer, the negative temperature coefficient thermosensitive resistor and the third resistor; a reference voltage part is formed by in series connecting the fourth resistor with the voltage-regulator tube; and a comparison and amplification part is formed by the second crystal triode and the fifth resistor connected with the collecting electrode of the second crystal triode. The thermosensitive resistor feedback sampling part samples output bias voltage; the comparison amplification part compares feedback sampling voltage with reference voltage and outputs to the first crystal triode in an amplifying way; and the first crystal triode realizes the regulation of the output bias voltage according to environment temperature. The temperature compensation circuit can effectively realize the temperature compensation of the bias voltage of the avalanche photodiode and has lower cost and power consumption and smaller volume compared with the traditional thermostatic apparatus.

The invention relates to the technical field of aluminum electrolysis, and concretely relates to an anticollision counterpoint method of multifunctional crown blocks for aluminum electrolysis. In the invention, a laser emitter, a laser receiver, and an arithmetic control unit CPU are arranged on an end carriage at one side of a crossbeam of each multifunctional crown block; two reflecting plates are arranged on two end carriages of the adjacent multifunctional crown blocks, and the two end carriages are opposite to each other; the laser emitter, the laser receiver, and a controller are fixed by a fixed carriage and a locking spring washer; the reflecting plates are fixed by a support frame; a precise power supply which comprises three-terminal voltage regulator tubes 7805 and 7815, a capacitor and a resistor provides power for the laser emitter, the laser receiver and the controller; and detection waves emitted by the laser emitter are reflected to a low frequency amplifier 9014 triode the laser receiver by the reflecting plate to preamplify, are subjected to signal amplification and double bridge filtering processing, are input to the CPU for operation, and are sent to the controller to execute alarm or control the crown blocks to stop. The application of the method of the invention can avoid the damage of crown block parts caused by the bump generated by the opposite motion of the multifunctional crown blocks, so the operation failure rate of the crown blocks is reduced. The method of the invention is suitable for the counterpoint control of the opposite motion of the multifunctional crown blocks for aluminum electrolysis.

A linear voltage regulator is provided for providing an output voltage to a load. In a preferred embodiment, the linear voltage regulator comprises: an operational amplifier receiving a regulated voltage, and a first voltage reference, and providing a driving voltage; a first regulating transistor driven by the driving voltage, the regulating transistor receiving a system voltage, and providing the regulated voltage; a second regulating transistor receiving the regulated voltage, and providing an output voltage, the second regulating transistor controlled by a controlling voltage; a resistive voltage divider receiving the output voltage, and providing a second voltage reference; and a three-terminal adjustable shunt regulator receiving the second voltage reference, and providing the controlling voltage to the second regulating transistor. Because the first regulating transistor pulls down the system voltage to the regulated voltage, the operating voltage of the second regulating transistor is lower than that of a typical linear voltage regulator, therefore the linear voltage regulator can provide a high-power to the load.

The invention belongs to the field of circuits, and provides an LED constant-current control circuit and an LED liquid crystal television. The LED constant-current control circuit consists of split elements including a switching tube, a voltage regulator tube, a functional resistor and a capacitor which are combined and connected, the switching tube has different high and low level states, so that LED load has different work states, use quantity of the elements is reduced, and the circuit is simple and cheap and is easy to debug, low in development difficulty and lowered in cost.

The invention discloses an electronic equipment analog signal calibration circuit. The circuit comprises a frequency acquisition circuit, a feedback constant current circuit and a push-pull output circuit. The frequency acquisition circuit acquires signal frequency in an analog signal channel in the low-voltage electronic equipment control terminal; the feedback constant current circuit utilizes atriode Q1, a triode Q2 and a voltage stabilizing tube D3 to form a constant current source circuit stable signal potential. Meanwhile, a current-voltage conversion circuit composed of a variable resistor R8 and an operational amplifier AR3 is used for converting a current signal into a voltage signal and inputting the voltage signal into a push-pull output circuit; an abnormal signal detection circuit is composed of a silicon controlled rectifier VTL1 and a voltage-regulator tube D4 and feeds back abnormal signals to the collector electrode of a triode Q2. and finally, the push-pull output circuit uses a triode Q3, a triode Q4 and a variable resistor R16 to form a push-pull circuit to reduce signal conduction loss and then output the signal, so that the signal frequency can be converted into a compensation signal of a signal in an analog signal channel in a remote intelligent equipment control terminal.

The invention relates to a vehicle-mounted low-dropout linear voltage stabilizer circuit. The vehicle-mounted low-dropout linear voltage stabilizer circuit comprises a three-end voltage stabilizing chip and a low-voltage compensating circuit. The low-voltage compensating circuit comprises a detection circuit, a high-voltage on circuit, a low-voltage on circuit and a compensating voltage stabilizing module. The vehicle-mounted low-dropout linear voltage stabilizer circuit is simple in structure, and can be realized by taking the conventional voltage detection circuits as the switching circuit and the voltage stabilizing tube of the high/low-voltage on circuit, and therefore, the modification cost is low. According to the vehicle-mounted low-dropout linear voltage stabilizer circuit, the three-end voltage stabilizing chip is activated to supply power when the voltage of an input voltage source is normal, and when the voltage of the input voltage source is relatively low, the voltage source and the voltage stabilizing tube are used for directly supplying power, and therefore, the normal working of a load is guaranteed and the stability of the vehicle-mounted load during working at a low voltage is improved.