65 results about "Unijunction transistor" patented technology

This disclosure describes systems, methods, and apparatuses for impedance-matching radio frequency power transmitted from a radio frequency generator to a plasma load in a semiconductor processing chamber. Impedance-matching can be performed via a match network having a variable-reactance circuit. The variable-reactance circuit can comprise one or more reactive elements all connected to a first terminal and selectively shorted to a second terminal via a switch. The switch can comprise a bipolar junction transistor (BJT) or insulated gate bipolar transistor (IGBT) controlled via bias circuitry. In an on-state, the BJT base-emitter junction is forward biased, and AC is conducted between a collector terminal and a base terminal. Thus, AC passes through the BJT primarily from collector to base rather than from collector to emitter. Furthermore, the classic match network topology used with vacuum variable capacitors can be modified such that voltages do not overload the BJT's in the modified topology.

The invention provides an automatic dimming table lamp. The automatic dimming table lamp is composed of a 220V alternating current power supply, a full-bridge rectifying circuit, a 9V voltage stabilizing circuit, a light-sensitive circuit, an optical signal amplification circuit, a bidirectional thyristor trigger circuit and a bidirectional thyristor control circuit, and is characterized in that the type of a unijunction transistor VT2 in the bidirectional thyristor trigger circuit is BT33. According to the automatic dimming table lamp provided by the invention, a light-sensitive resistor is placed in a proper position of a table lamp, and the intensity of illumination around the table lamp can be automatically adjusted to a proper value, thereby reducing the trouble of manual dimming and protecting the eyesight of students. Simultaneously, the automatic dimming table lamp also has a function of stabilizing the light brightness, thus when 220V alternating voltage fluctuates, the brightness of the table lamp is kept unchanged. The brightness of the dimming table lamp can be changed by only changing the distance between the light-sensitive resistor and the bulb of the table lamp, thereby being very convenient to use. The automatic dimming table lamp is suitable for factories to develop a novel table lamp with a function of automatically controlling illumination.

A parameter extraction method for integrated gate commutated thyristor drive turn-off circuit and continuing current circuit. The method consists of the following steps: S1. analyzing running characteristics of the integrated gate commutated thyristor drive circuit and the continuing current circuit, proposing an equivalent circuit during the integrated gate commutated thyristor turn-off transient continuing current process; S2. according to the equivalent circuit obtained in S1, deducing voltage expressions of the integrated gate commutated thyristor in different states; S3, carrying out a unijunction transistor testing experiment of the integrated gate commutated thyristor, by virtue of a specific clamping voltage and experiment results of electric quantities of the integrated gate commutated thyristor and the continuing current circuit when current is turned off during the integrated gate commutated thyristor turn-off transient process, proposing the parameter extraction method for the integrated gate commutated thyristor drive turn-off circuit and continuing current circuit; and S4,for the integrated gate commutated thyristor, carrying out experiments on different voltage grades and the turn-off circuits, through processing of the different experiment results, determining parameter values of the integrated gate commutated thyristor drive turn-off circuit and continuing current circuit.

The invention provides a desk lamp with automatically regulated brightness. The desk lamp with automatically regulated brightness comprises a 220V AC power supply, a full bridge rectifier circuit, a 9V voltage regulator circuit, a light-sensing circuit, an optical signal amplifying circuit, a relaxation oscillation circuit and a double-direction controllable silicon control circuit, and is characterized in that the type selected by a unijunction transistor VT2 in the relaxation oscillation circuit is BT33. The desk lamp with automatically regulated brightness is characterized in that a photoconductive resistor is arranged on a suitable location of the desk lamp, the illuminance surrounding the desk lamp can be automatically regulated to a suitable value, thus the trouble of manual dimming can be reduced and the vision of the students can be protected; moreover, the desk lamp with automatically regulated brightness also has the function of stabilizing the lamp brightness, and the brightness of the desk lamp can be always remained unchanged when a 220V AC voltage fluctuates. The desk lamp has the advantages of simple circuit because normal components are used, and manufacture cost of only more than ten yuan, and is suitable for batch development.

An embodiment of the invention discloses an automatic regulating voltage stabilizing circuit. The circuit includes a photosensitive triode VT1, a unijunction transistor VT2, a thyristor VT3, a rectifier bridge BD1, a fuse F1, an alternating current light source LAMP, resistors R1, R2, R3, R4, R5 and R6; a collector electrode of VT1 is connected with one end of R1, one end of R2 and one end of R3; an emitting electrode of VT1 is connected with a fourth pin of BD1, the other end of R2, one end of R4, a third pin of R6 and a cathode of VT3; an emitting electrode of VT2 is connected with the other end of R3 and the other end of R4; a base electrode of VT2 is connected with a second pin of R6; the other base electrode of VT2 is connected with a gate pole of V3; and an anode of VT3 Is connected with a second pin of BD1, the other end of R1 and one end of R5. The automatic regulating voltage stabilizing circuit in the embodiment of the invention has the advantages of simple structure, convenient control and low cost.

The invention relates to a work method of an electronic release, which is characterized in that: a current transformer is used for detecting a signal and transforming primary large current to lower output voltage to be supplied to other links; after an output voltage signal is taken out, the low output voltage is transformed to direct-current voltage through a bridge-type rectifier circuit and a resistance-capacitance filter circuit; then the direct-current voltage is divided by a resistor to be inputted to a signal comparison link, and the signal comparison is realized by utilizing a silicon voltage-regulator tube or a unijunction transistor; when the signal voltage exceeds the breakdown voltage of the voltage-regulator tube or the peak voltage of a double-base junction transistor, the voltage-regulator tube or the double-base junction transistor is conducted, and a signal is outputted; and when a trigger is conducted, an armature of an electromagnetic-type release or an electromagnetic induction-type release is actuated, or the magnetic flux of a permanent magnet is weakened because of different polarities of conductive current, the armature on the release is released, and finally a traction rod is facilitated to move, and a circuit breaker is tripped. Due to the adoption of the work method of the electronic release, the safety of the circuit can be guaranteed, the protection function of the circuit breaker is gradually completed, and the circuit breaker is more flexible to control and is simpler and more convenient to operate. The sensitivity is high, and the protection work range is wide.

The invention discloses an energy-saving and reliable AC electric welding machine. The machine comprises an AC power supply, a first switch, a second switch, a first fuse, a second fuse, a first relay, a second relay, a first capacitor, a second capacitor, a third capacitor, a normally-opened contact switch of the first relay, a normally-closed contact switch of the second relay, a transformer, a welding handle, a first diode, a second diode, a third diode, first to seventh resistors, first to fourth voltage-stabilized diodes, a potentiometer, an one-way thyristor and an unijunction transistor; the first relay is powered off, the first capacitor is connected to a loop of the transformer, and the electric welding machine enters an idle load energy saving state under the current limiting effect of the first capacitor; when a welding part is in contact with the welding handle and after 5 seconds that the electric welding machine is stopped from normal work, the electric welding machine enters the idle load state. With the adoption of the machine, the standby current of a primary coil of the transformer can be automatically reduced when welding is not carried out, and thus the energy consumption of the electric welding machine can be reduced; the electric welding machine has the characteristics of being simple in structure, and reliable in performance during working.

The invention discloses a small electronic mosquito repelling device used in agriculture and livestock husbandry. The device comprises a potentiometer, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a potentiometer, a uni-junction transistor, a triode, a crystal oscillator, a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode, a switch and a direct-current power supply. The device comprises a mosquito repelling circuit generating ultrasonic waves. The circuit structure is simple, and the manufacturing cost is low. A plurality of the devices can be placed in different corners, such that mosquitoes can be repelled comprehensively. The device is especially suitable for agriculture and livestock husbandry in relatively remote areas, and helps in providing a reliable culturing environment for farmers.

The embodiment of the invention discloses a power-adjustable rectifying circuit, comprising a rectifying circuit and a triggering circuit; the rectifying circuit comprises two thyristors and two diodes, which form a first rectifying bridge circuit connected to a mains supply; the triggering circuit comprises a relaxation oscillation circuit formed by unijunction transistors; the relaxation oscillation circuit is provided with an RC oscillation circuit and an adjustable resistor capable of adjusting oscillation frequency; and the triggering circuit also comprises a synchronous transformer, a second rectifying bridge circuit connected with the synchronous transformer and a voltage-regulator tube for performing clipping on the second rectifying bridge circuit to power the relaxation oscillation circuit. After the power-adjustable rectifying circuit is adopted, switch control signals of the thyristors are provided for the rectifying circuits by the synchronous triggering circuit, thus enabling the power size of the output circuit of the rectifying circuit to be adjustable. The power-adjustable rectifying circuit can be used as a control unit for power controlling, can be used for the non-polar speed adjusting of a motor and the power control unit for electromagnetic heating, and is simple in structure and stable in performance.

The invention relates to a small sealing release delay relay with long delay time. A programmable unijunction transistor V5 is taken as a potential comparison and drive element, a contact of a sealing magnetic latching relay J is taken as an output switching contact, and a three-layer structure design is adopted. The size is small, the environmental adaptation performance is good, the reliability is high, the delay time is up to 1200s, and the leakage rate is less than or equal to 1*10<-1>Pa.cm<3> / s.

The invention discloses an alternating current voltage regulating device for a projection lamp. The alternating current voltage regulating device comprises a rectifying circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first transistor, a second transistor, a phototriode, a unijunction transistor, a thyristor, a capacitor and a potentiometer. A transistor automatic alternating current voltage regulating circuit is adopted, so the first transistor, the second transistor and the phototriode play the function of equivalent resistors, when light rays of the projection lamp change along with the change of the power supply voltage, the resistance of the phototriode changes, the voltage phase controlling the unijunction transistor is changed, so that the pulse phases of the transistors move, the breakover time of the transistors is increased or decreased, and the voltage of a bulb of the projection lamp is enabled to approximately remain unchanged. The alternating current voltage regulating device adopts the transistor automatic alternating current voltage regulating circuit, enables the brightness of the bulb of the projection lamp to be relatively stable, can enable the brightness of the bulb to be stable under the condition that the voltage is instable, and further protects the bulb from being burnt.

The invention discloses an anti-mosquito paper diaper, and belongs to the technical field of infant daily supplies. The anti-mosquito paper diaper comprises a breathable outer layer and a water absorption inner core, wherein a mosquito dispeller and a plant essence extract are arranged in the water absorption inner core; the mosquito dispeller consists of a unijunction transistor oscillating circuit, an ultrasonic signal amplification circuit and an ultrasonic output circuit. The anti-mosquito paper diaper disclosed by the invention adopts a sound wave anti-mosquito mode, substances harmful to the health of people or odorous substances cannot be generated, sound waves beneficial for infant growth are further emitted, and infant sleep is facilitated; through the added plant essence extract, on one hand, the moisture absorption performance of the paper diaper is increased, and on the other hand, the antibacterial and bactericidal effects of the paper diaper are increased.

The invention discloses an electric welding machine safe electricity-saving starting device which comprises a double-linkage switch, a relay, a contactor, a fuse protector, an electric welding machine transformer, a welding gun, a unijunction transistor, a first voltage-regulator tube, a second voltage-regulator tube, a first capacitor, a second capacitor, a third capacitor, a first resistor, a second resistor and a third resistor. During welding, an electric welding machine secondary pole is subjected to short circuiting, voltages are lowered to about 0V, the relay loses power and is released, the contactor obtains power and is closed in an attracting mode, and an electric welding machine is in a next-step normal welding state. During operation, safety, energy saving and reliability are achieved, the number of used elements is low, economy, convenience and practicability are achieved, operation is natural, working is free, and operation is smooth and comfortable. When welding is not carried out, the electric welding machine is in a power-off state, the potential safety hazards that the electric welding machine is not used and has electricity are lowered, during welding, the switch does not need to be turned on manually, accordingly, high power consumption of the electric welding machine is lowered, and the working efficiency of the electric welding machine is improved.

The invention belongs to the field of the application of an electronic technology and relates to a single-phase AC (Alternating Current) full-automatic non-contact voltage stabilizer, consisting of a commercial power supply, a full-bridge rectifying circuit, a self-coupled voltage regulator, and a half-wave DC (Direct Current) circuit and a relaxation-oscillator circuit for controlling silicon controlled rectifier (SCR), wherein the model of a unijunction transistor in the relaxation-oscillator circuit is BT33. By taking the working principle of the servo motor AC voltage stabilizer as reference, the single-phase AC full-automatic non-contact voltage stabilizer provided by the invention has the advantages of simple structure of circuit, realization of non-contact voltage regulation, rapid and accurate response to voltage regulation, no waveform distortion and suitableness for the commercial AC voltage range from 160 V to 290 V; and a large number of copper materials are saved. The voltage stabilizer has no voltage switching contact, so that no electromagnetic interference generated by contact sparking occurs, and no pollution is caused to the power grid; and in particular, the voltage stabilizer provided by the invention is suitable for regions with larger voltage fluctuation range of a power grid and can replace various traditional high-power AC voltage-stabilized sources in the market.

The invention discloses a high-capacity-motor slow-starting protective device which includes a motor, an AC power supply, a rectifying circuit, a bidirectional SCR, a unijunction transistor, a transformer, a sliding rheostat, a voltage-stabilizing tube, a fifth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor and a second capacitor. The protective device undergoes current limiting and voltage stabilization by the first resistor after being rectified by the rectifying circuit and then charges the high-capacity capacitors and delays gradual increasing of an opening angle of the bidirectional SCR by triggering pulses through discharge capacity of the sliding rheostat to the unijuction transistor. Even if the resistance of the sliding rheostat is adjusted to the minimum, the bidirectional SCR does not switch on completely immediately so that a soft-starting objective is achieved. Through adjustment of the sliding rheostat, soft starting speed of the motor can be changed. Through adoption of the soft starting, the high-capacity-motor slow-starting protective device is capable of limiting impulse current of a refrigeration motor so that motor burning is prevented, service life of the motor is prolonged and inconvenience brought to work by motor burning is reduced.

The invention discloses an alternating-current voltage regulation circuit for a multimedia projector. The alternating-current voltage regulation circuit for the multimedia projector comprises a projection lamp, a first diode, a second diode, a third diode, a fourth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first triode, a second triode, a third triode, a unijunction transistor, a thyristor and a capacitor. Compared with the prior art, the alternating-current voltage regulation circuit for the multimedia projector adopts the phototriodes to control the thyristor to automatically regulate voltage, so that the light of the projector can be stabilized sufficiently, and the circuit is simpler in structure and lower in manufacturing cost, and has higher popularization and promotion values.

The invention relates to a direct-current power supply driving device for a fluorescent lamp. The direct-current power supply driving device is characterized by comprising a 12V direct-current power supply, an oscillating auxiliary circuit, a field effect transistor driving circuit and a boosting and illuminating circuit, wherein the oscillating auxiliary circuit consists of an NPN type transistor VT1, a resistor R1, an NPN type transistor VT3 and a programmable unijunction transistor VT4; the model of the programmable unijunction transistor VT4 is 2N6027; the drain of an enhanced N-channel field effect transistor VT2 in the field effect transistor driving circuit is connected with one end of a primary coil L1 of a transformer T; the other end of the primary coil L1 of the transformer T is connected with the positive electrode VCC of a circuit; the grid of the enhanced N-channel field effect transistor VT2 is connected with the emitter of the NPN type transistor VT1; the drain of the enhanced N-channel field effect transistor VT2 is connected with circuit ground GND through a resistor R2; the boosting and illuminating circuit consists of a boosting coil L2 of the transformer T, a capacitor C1 and a fluorescent lamp RGD.

The invention discloses a soft start control device for a high-power motor. The soft start control device comprises a motor, an alternating current power supply, a rectifying circuit, a bidirectional thyristor, a unijunction transistor, a transformer, a sliding rheostat, a voltage-regulator tube, a fifth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor and a second capacitor. According to the soft start control device, after the rectifying circuit performs rectification, current limitation is performed through the first resistor and after voltage stabilization, the large-capacity capacitors are charged; gradually-increasing (from small to large)of a turn-on angle of the bidirectional thyristor due to trigger pulses can be delayed through the discharge quantity of the sliding rheostat to the unijunction transistor; and even if the resistance value of the sliding rheostat is adjusted to a minimum value, the bidirectional thyristor cannot be connected fully immediately, thereby achieving the purpose of soft start. The speed of the soft start of the motor can be changed through adjusting the sliding rheostat. Through adopting soft start, a surge current of a cold motor can be limited, the motor can be prevented from being burned out, the service life of the motor can be prolonged and inconvenience caused by motor burning in work is reduced.

The invention discloses a wireless charge controllable nerve stimulator and device. The nerve stimulator comprises an antenna coil, a circuit part, a stimulation electrode anode and a stimulation electrode cathode; and the circuit part comprises a tuning capacitor, a rectifier, a Zener diode, a filtering capacitor, a bias resistor, a blocking diode, a charging resistor, an output capacitor and a unijunction transistor. According to the invention, it is ensured that small-size unit can be implanted, charge is used to control the stimulation output intensity, the circuit uses common discrete components, the circuit structure is simple, the cost is low, the reliability is high, it is not required to prepare a special integrated circuit chip, realization is convenient and rapid, the transplantability is high, and values of the discrete components can be modified simply to realize different stimulation functions of the nerve stimulator.

The invention provides a three-phase silicon controlled rectifier circuit with single-pulse distribution and triggering, relating to a silicon controlled rectifier excitation device of a three-phase synchronous motor rotor. The circuit comprises a synchronous circuit, a pulse forming circuit, and a pulse distribution circuit. The synchronous circuit mainly comprises three paths of synchronous signal acquisition circuits corresponding to a three-phrase power supply, and each circuit is composed of a resistor, diodes and voltage stabilizing tubes that are connected in series. The pulse forming circuit mainly comprises a PNP transistor (BG201), a uni-junction transistor (BG202), and a capacitor (C205). The pulse distribution circuit comprises an integrated module (MF-01). The invention is characterized in that the circuit realizes automatic tracking of trigger pulse through the simple synchronous circuit, the pulse forming circuit and the pulse distribution circuit instead of three-phase sinusoidal wave synthesis, so that the three-phase power supply can randomly connected without phase recognition. The circuit is very simple, and the required elements are less (1 / 10 of conventional circuit), so that the control circuit has small volume and low cost.

The invention discloses an anti-false-collision robot emergency stop circuit. A push rod is connected with a displacement sensor for detecting the stroke, and a push rod stroke signal detected by thedisplacement sensor is processed by a stroke change rate calculation circuit, a false-collision decision circuit and an interlocking output circuit and then connected with a normally closed contact inseries to act on a power supply loop of the robot, so that the problem that an emergency stop button is mistakenly touched in use to cause mistaken stop is effectively solved. According to the emergency stop circuit, the stroke change rate in unit time is calculated through the push rod stroke signal, and whether the emergency button is manually pressed in an emergency situation or not is preliminarily determined by triggering the conduction and cut-off of a triode Q1 and a triode Q2 according to the stroke change rate; whether the push rod stroke reaches the lower limit position or not is determined by combining the states of a triode Q3 and a single-junction transistor T1, so that whether the emergency stop is manual and normal or not is determined; and the state of a photoelectric coupler U2 connected with the normally closed contact in series is controlled by outputting a high level and a low level, so that the power supply loop acting on the robot is reliably disconnected in an interlocking manner when the emergency stop is manually and normally carried out.

The invention relates to an alternating-current non-contact voltage regulator. The voltage regulator consists of a 220 V alternating-current power supply, a full-bridge rectifying circuit, an auto-voltage regulator and half-wave rectifying circuit, mono-direction-controlled silicon, and a relaxation oscillation circuit. The model of a unijunction transistor used in the relaxation oscillation circuit is BT33. By referring to the working principle of a servo motor alternating-current voltage stabilizer, the alternating-current non-contact voltage regulator has the advantages that: the circuits have simple structures, non-contact voltage regulation is realized, the response to voltage regulation is quick, voltage regulation is accurate, waveform distortion is avoided, the application range of mains alternating-current voltage is 160 to 260V, and a large number of copper materials are saved. The voltage regulator does not have any voltage switching contact, so electromagnetic interference caused by contact strike cannot occur, a power grid cannot be polluted, and the alternating-current non-contact voltage regulator is particularly applied to regions of which the fluctuation range of power grid voltage is wider, and can substitute various traditional high-power voltage regulating power supplies in the market.

The invention discloses an intelligent silicon rectifier charger, includes insulation base, output port, charging box, new filling material, battery, transfer switch, T-type insulation bolt, negativeelectrode, coolant, current regulator, fixed separator, one-junction transistor oscillation trigger circuit device, insulation safety door, full-touch electronic display screen, safety signal lamp andinsulation anti-slip grip. The invention has the advantages that: the new filling material ensures the safety and normal operation of the internal main charging circuit, the coolant ensures the normal and safe operation of the battery, The current regulator contains the positive side of the power supply. micro-regulator, and a fuse device for regulating and controlling the current in the main charging circuit, fixing the separator to increase the charging efficiency of the charger, ensuring the circuit safety by the single-junction transistor oscillation trigger circuit device, balancing thetotal output current and voltage, facilitating the manipulation of the user by the full-touch electronic display screen, and visually observing the output situation of the internal current and voltage, etc.

The present invention discloses a real estate payment and certificate integrated device intelligent terminal device. An anti-jamming circuit performs inhibition, electromagnetic interference absorption and frequency selection of receiving signals, the receiving signals are transmitted into a signal amplitude regulation circuit, an operational amplifier AR1 is taken as a core amplifier for scale amplification, a window circuit is employed to detect whether the amplitudes of the signals are abnormal or not, when the signal amplitude is abnormal, difference value signals are added to a transmitting electrode of an unijunction transistor Q1, a conduction angle of the unijunction transistor Q1 is changed to change signals coupled to the input end of the operational amplifier AR1 to regulate thesignal amplitude, when the signal amplitude is normal, the signals are transmitted to a delaying voltage stabilizing circuit, the signals after scale amplification are processed by a filter circuit and a hysteresis comparator to eliminate tiny voltage change near the signal amplitude values after the scale amplification of the signals so as to input the stable voltage into a control terminal signal transmission channel in a real estate payment and certificate integrated device intelligent system after improving the antijamming capability and effectively solve the technical problems that the attenuation, the anti-jamming and the stability of signal transmission are poor in the data safety intelligent operation and maintenance monitoring system.

The invention discloses a manual temperature adjustment electrothermal seat cushion which is characterized by comprising a 220V alternating-current power supply, a full-bridge rectifying circuit, a 12V voltage stabilizing circuit, a temperature adjustment control signal and signal amplification circuit, a bidirectional controllable silicon triggering circuit and a bidirectional controllable silicon control circuit, wherein the temperature adjustment control signal and signal amplification circuit consists of a PNP-type transistor VT1, a resistor R2, a resistor R3, a resistor R4 and a linear potentiometer RP; the bidirectional controllable silicon triggering circuit consists of a unijunction transistor VT2, a capacitor C1 and a resistor R5; the model of the unijunction transistor VT2 is BT33; according to the bidirectional controllable silicon control circuit, a second positive electrode T2 of bidirectional controllable silicon BCR is connected with a positive electrode output end of the full-bridge rectifying circuit through electrothermal cloth SGC; a control electrode G of the bidirectional controllable silicon BCR is connected with a first base B1 of the unijunction transistor VT2; a first positive electrode T1 of the bidirectional controllable silicon BCR is connected with a negative electrode output end of the full-bridge rectifying circuit.

The invention discloses a simple infrared safety protection electronic product detector comprising a direct-current power source, first to sixteenth resistors, an alarm signal lamp, first to fifth capacitors, first to sixth triodes, a first light-emitting diode, a second light-emitting diode, a first photosensitive transistor, a second photosensitive transistor, and an adjustable unijunction transistor. When an object blocks light of the first light-emitting diode light from being irradiated on the photosensitive transistors, the first photosensitive transistor is switched from a switched-on state to a switched-off state, and the second light-emitting diode and the second photosensitive transistor amplify power and transmit the power to the alarm device. Compared with the prior art, the simple infrared safety protection electronic product detector of the invention has the advantages of simple circuit structure, low cost, small size and easy carrying, is convenient to maintain and overhaul, and is easier to popularize and promote.

The invention provides an ESD protection device for a fully-depleted silicon-on-insulator and a preparation method of the ESD protection device. The device comprises bottom layer silicon which has P-type low doping, a buried oxide layer which is formed on the bottom layer silicon, a top layer silicon which is formed on the buried oxide layer and has P-type low doping, a first N-type heavily doped region which is formed in the top layer silicon, a second N-type heavily doped region which is formed in the top layer silicon, a P-type heavily doped region which is formed on the top layer silicon between the first N-type heavily doped region and the second N-type heavily doped region, a first base electrode which is electrically connected with the first N-type heavily doped region, a second base electrode which is electrically connected with the second N-type heavily doped region, an emitter electrode which is electrically connected with the P-type heavily doped region, and a gate electrode which is electrically connected with the bottom layer silicon. According to the ESD protection device, the unijunction transistor is used for forming a voltage stabilization structure, high-voltage ESD protection is achieved, and the ESD protection device is suitable for the fully-depleted silicon-on-insulator.

The invention discloses a power-saving controller for an electric welding machine. The controller comprises a double coupled switch, a relay, a contactor, a fuse protector, an electric welding machine transformer, a welding gun, a unijunction transistor, a first voltage-regulator tube, a second voltage regulator tube, a first capacitor, a second capacitor, a third capacitor, a first resistor, a second resistor and a third resistor, wherein during welding, as the secondary level of the electric welding machine is short-circuited, the voltage is reduced to around zero volt, the relay is released due to power loss, and the contactor is pulled in after being charged, the electric welding machine gets into a normal welding state in the next step. According to the invention, the controller is safer, more energy-saving and reliable to operate, adopts few components, is economical, convenient and practical, and can be operated naturally, freely, smoothly and easily; as the welding machine is in off-position during welding, the safety hazard that the electric welding machine is electrified when not used is reduced; as the switch can be turned on without manual operation during welding, the defect that the electric welding machine is high in power consumption is reduced, and the working efficiency of the electric welding machine is improved.