140results about How to "Low residual pressure" patented technology

A bypass passage for bypassing a check valve is connected with a vacuum introducing passage of a brake booster. The bypass passage is provided with a switching valve. Just before the start of an engine, the switching valve temporarily opens the bypass passage whereby to equalize a remaining pressure of the brake booster substantially becomes equal to an atmospheric level. As a result, the pressure in the brake booster at the starting time is set to substantially the atmospheric level so that the airflow to be sucked from the brake booster into the intake pipe at the starting time is made substantially contact every times. Thus, the fuel injection rate can be set considering the airflow to be sucked from the brake booster into the intake pipe at the starting time, even if that airflow cannot be detected.

The controllable arrester in metal oxide includes control part and fixed part connected in series. In normal operation of system, the control part and the fixed part together bear system voltage. When amplitude value of system over voltage exceeds prearranged threshold value, the fixed part bears system over voltage. Combining power electronic device in large power with arrester in metal oxide (MO), the invention puts forward concept and designing idea of controllable arrester for aiming at issue of over voltage protection for transmission system in super voltage, extra high voltage. Based on condition of maintaining invariable performance parameters of MO resistance piece, the invention reduces residual voltage of arrester effectively by using characteristics: quick response speed of power electronic device, steady operation, and flexible adjustment so as to raise protection level for arrester.

The invention discloses a varistor ceramic preparation method reducing ZnO grain resistivity. The preparation raw materials include zinc oxide ZnO, bismuth oxide Bi2O3, antimonous oxide Sb2O3, manganese dioxide MnO2, chromium oxide Cr2O3, cobalt oxide Co2O3, silicon dioxide SiO2 and indium nitrate crystal In(NO3)3.9H2O; and the preparation steps include a step of seed crystal roughing, a step of primary sintering, a step of seed crystal refinement, a step of raw material mixing and a step of secondary sintering. The method has the following beneficial effects: by strictly changing the control technology flow and the control technology parameters, the structural components and structural change of the material in the preparation process can be manually controlled, the grain resistivity and the residual voltage of ZnO varistor are reduced while the increase of leakage current and the decrease of nonlinear coefficient are inhibited, and thus the material has higher performance and is more suitable for industrial application.

The invention relates to a multi-gap metal gas discharge tube (hereinafter referred to as M-GDT) power supply over-voltage protection module, which mainly consists of the M-GDT. A terminal electrode A of the M-GDT is in conducive connection with a phase line L of a power supply, A terminal electrode A' of the M-GDT is in conductive connection of a neutral line N or a protective earth PE of the power supply, intermediate electrodes of K1-Kn of the M-GDT are respectively in conductive connection with one ends of voltage dependent resistors of MOV1-MOVn, and the other ends of the MOV1-MOVn are in conductive connection with the terminal electrode A or the terminal electrode A' of the M-GDT. The product of the invention has no potential safety hazard, large current capacity, no continuous current, high reliability and good stability.

The invention provides a DC controllable lightning arrester device. The DC controllable lightning arrester device comprises a lightning arrester body and a hybrid switch, wherein the lightning arrester body comprises a lightning arrester fixed part and a lightning arrester controllable part, the lightning arrester fixed part and the lightning arrester controllable part respectively comprise at least one column of lightning arrester units, one end of a parallel circuit formed by the lightning arrester controllable part and the hybrid switch is grounded, the other end is connected with the lightning arrester fixed part, the hybrid switch comprises a thyristor valve switch and a mechanical switch which are connected in series, and the hybrid switch is connected with two ends of the lightningarrester controllable part in parallel. The DC controllable lightning arrester device is advantaged in that the thyristor valve switch and the mechanical switch are utilized to form the high voltage DC hybrid switch type controllable lightning arrester, the thyristor switch is ensured to be reliably turned off, so the lightning arrester returns to normal operation, the lightning arrester body achieves dual functions of energy release and overvoltage suppression, a charge rate of the whole lightning arrester under the operation voltage is reduced, the safety margin of the lightning arrester isimproved, and reliability of the lightning arrester is enhanced.

Disclosed is a backup protection unit of a surge protector, which is connected to the surge protector. The backup protection unit includes: a faulty driver, a tripping mechanism, a contact switch, an operating handle and an indicator, and a faulty driver is connected in parallel with a surge bypass. Alternatively, the backup protection unit includes a fault protector and an indicator, the fault protector is connected in series with a surge blocker, and surge bypassers are connected in parallel at both ends of the series circuit formed by the series fault protector and surge blocker. The surge bypass device provided by the present invention realizes the effective separation of surge and fault current, diverts the surge energy that the fault driver should bear, and thus improves the surge impact capability.

The invention relates to a coaxial channel lightning protection device circuit, which comprises a gas discharge tube I, a transient voltage suppressor diode (also called TVS diode) II, a coupling resistor R and a fast recovery diode D; the gas discharge tube I is connected with the transient voltage suppressor diode II through the coupling resistor R. Compared with the prior art, the circuit provided by the invention has the advantages of large through-flow capacity (5KA), fast response speed (nano-second level), small volume, convenience in installation and the like; as a multi-level protection circuit is adopted, the residual voltage is low; and moreover, the circuit is suitable for overvoltage protection of related devices which transmit videos and data signals through a coaxial cable, and can protect the device from being damaged by sensing the overvoltage and operating the overvoltage.

The invention relates to a conversion current and over-voltage protection technology of electric equipment, in particular to a protector for preventing interception over-voltage and arc reignition over-voltage of a vacuum circuit breaker. A valve body of the protector is assembled by mutual series-parallel connection of a column-type valve plate RN1 of a ZnO non-linear resistor, a ring-type valveplate RN2of a Sic non-linear resistor, and a column-type valve plate RN3 of a ZnO non-linear resistor ; then output ends are connected to both ends of DL movable and stationary main contacts in parallel. The vacuum circuit breaker has the ability of converting current and limiting voltage when the large current is switched on and off, and the function of preventing the interception over-voltage and the arc reignition over-voltage when the low current is switched on and off. When the circuit breaker closes the switch, the current flows from both ends of the main contacts and does not flow in the protector, thus the protector can not have the aging problem, a loop can not cause the reignition over-voltage in the process of switching on and off, thereby protecting the main contact against burning or shortening the service life due to the arc reignition.

The lighting protector comprises the power input end, the consumer end and the lightning protection ground. The characters are that the reactor is connected between the power input end and the consumer end. The first stage lighting protection circuit as sealed type spark gap is connected between the power input end and the lightning protection ground. The second and the third lightning protection circuit are connected between the consumer end and the lightning protection ground. The second lightning protection circuit is a metallization thin film capacitor, and the third lightning protection circuit is zinc oxide piezoresistor. The reactor possesses the magnetic core with high magnetic inductivity. Flat copper wire is used for the connecting wire.

Disclosed is a distribution system concentrated ground protection and lightning protection device and system. The distribution system concentrated ground protection and lightning protection device comprises a power source protection unit and a ground protection unit, an external power source supplies protected devices with power through the power source protection unit, the device ground PE (protecting earthing) ends of the protected devices are connected with a concentrated ground wire through the ground protection unit for grounding, and according to the system, all RRUs (Radio Remote Units) are subjected to concentrated grounding through the concentrated ground wire by all BBUs (Building Base band Units) of more than one protected device. Due to the fact that a concentrated grounding technology is utilized in the distribution system concentrated ground protection and lightning protection device and system, grounding can be performed through alternating current null wires or direct current positive wires, and concentrated grounding can also be achieved through power cable shielded wires or by adding a protective ground wire to a power cable.

The invention provides a surge protection circuit. The surge protection circuit comprises a bidirectional voltage suppressor and a thyristor-type surge suppression unit, wherein the thyristor-type surge suppression unit is connected with the bidirectional voltage suppressor in parallel; the first end of the bidirectional voltage suppressor is connected with the first end of the thyristor-type surge suppression unit; the second end of the bidirectional voltage suppressor is connected with the second end of the thyristor-type surge suppression unit; the surge protection circuit is characterized in that the breakover voltage or breakdown voltage in the direction from the first end to the second end of the thyristor-type surge suppression unit is higher than the clamping voltage in the direction from the first end to the second end of the bidirectional voltage suppressor; the breakover voltage in the direction from the second end to the first end of the thyristor-type surge suppression unit is smaller than the clamping voltage in the direction from the second end to the first end of the bidirectional voltage suppressor. The invention further provides an electronic device with the surge protection circuit.

The invention discloses a lightning protection device comprising a piezoresistor and a gas discharge tube, the piezoresistor is provided with a first surface and a second surface opposite to the firstsurface, and a first electrode connected with the piezoresistor is welded on the first surface of the piezoresistor, and a second electrode connected with the piezoresistor is welded on the second surface of the piezoresistor, one side face of the gas discharge tube is welded on the second surface of the piezoresistor and is connected with the second electrode, and a third electrode connected with the gas discharge tube is welded on the other side face of the gas discharge tube. The invention further discloses a surge protection device comprising the lightning protection device. Due to the direct welding of the lightning protection device with the gas discharge tube through the piezoresistor, the welding pins and welding points are reduced, the circuit loop is shorter, and meanwhile, theresidual voltage of the whole lightning protection device circuit can be lower, and the corresponding time is shorter.

The invention relates to the technical field of piezoresistor discs for lightning arresters, in particular to a zinc oxide resistor disc and a preparation method and application thereof. The zinc oxide resistor disc provided by the invention is prepared from the following raw materials in percentage by mole: 85-95% of ZnO, 0.01-4.0% of Bi2O3, 0.01-4.0% of Sb2O3, 0.05-3.0% of Co2O3, 0.01-2.0% of MnO2, 0.01-3.0% of NiO, 0.01-2.0% of Fe2O3, 0.01-2.0% of A12O3, and 0.01-2.0% of Dy2O3. According to the zinc oxide resistor disc provided by the invention, a toxic substance Cr2O3 does not need to be added, various components including ZnO, Bi2O3, Sb2O3, Co2O3, MnO2, NiO, Fe2O3, Al2O3 and Dy2O3 cooperate with each other, such that the zinc oxide resistor disc has the excellent performances of highpotential gradient, high square wave through-flow capacity, low residual voltage, high square wave current and large current impact resistance, good aging resistance and the like.

The invention discloses a preparation method of a medium-voltage gradient zinc oxide piezoresistor MOV chip. The preparation method comprises the following steps: (1) preparing raw materials: zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, nickel oxide, aluminum nitrate and silver nitrate; (2) mixing and grinding a doping material; (3) carrying out continuous ball milling; (4) spraying, drying, and granulating; (5) forming; (6) discharging glue; (7) sintering; (8) carrying out ball-milling and cleaning on the black bare chip; (9) carrying out annealing heat treatmenton the product; (10) coating with silver to form a conductive electrode, and reducing the conductive electrode; (11) coating the side surface with an insulating glaze; (12) welding a copper conductingwire electrode; and (13) packaging, and encapsulating to obtain the product. According to the invention, the piezoresistor can improve the power frequency voltage/current tolerance time under the same voltage gradient so as to provide enough tripping action time for a thermal tripping device of a surge protection device SPD.

The invention relates to the technical field of lighting protection devices, and discloses an isolating-type bidirectional communication signal lighting protection device. The isolating-type bidirectional communication signal lighting protection device comprises a lighting protection circuit, an active isolating circuit and a power supply circuit. The lighting protection circuit comprises a first gas discharge tube GDT1, a second gas discharge tube GDT2, high-speed rectifier tubes D3, a transient voltage suppressor TVS and a current-limiting resistor R1. All signals are connected with the isolating input end reference ground GND2 through the first gas discharge tube GDT1 and the transient voltage suppressor TVS respectively and connected with the lighting protection ground through the second gas discharge tube GDT2, the current-limiting resistor R1 is connected between the first gas discharge tube GDT1 and the transient voltage suppressor TVS in series, and the high-speed rectifier tubes D3 are connected with the first gas discharge tube GDT1 in a star-shaped mode. The active isolating circuit comprises magnetic coupling signal transceiver U1, a signal transceiver U2 and monostable triggers U3. According to the isolating-type bidirectional communication signal lighting protection device, several-ten-of-thousand-of-volt lightning induction is reduced to hundred-of-volt pulse voltage through the lighting protection circuit, the hundred-of-volt pulse voltage is then reduced to power supply voltage through the active isolating circuit, and therefore residual voltage of the product is minimized.

The invention relates to a novel surge protection device which mainly comprises a breaking switch, a tripping mechanism, an inertia device (inertia wheel), a displacement buffer elastic sheet, an electromagnet, a bimetallic strip, a lightning protection element, an upper terminal and a lower terminal. The upper terminal is connected with the breaking switch, the electromagnet, the lightning protection element and the lower terminal in series. The electromagnet can drive the tripping mechanism to move, the displacement buffer elastic sheet and the inertia device (inertia wheel) are arranged on the tripping mechanism, it is guaranteed that the device moves as long as an ejector rod of the electromagnet moves continuously, the ejector rod of the electromagnet moves fast and restores at the moment that lightning currents pass, the tripping mechanism does not move, and it is guaranteed that the breaking switch accurately switches off an SPD fault access. The temperature of the lightning protection element is transmitted to the bimetallic strip through a heat conduction paster, and when the temperature is too high, the bimetallic strip can be deformed to drive the tripping mechanism to move to switch off the circuit. The novel surge protection device has the comprehensive lightning preventing function, power frequency short-circuit currents can be switched off fast, tripping is carried out when leakage currents are too high, the lightning currents are discharged smoothly, and the novel surge protection device is convenient to mount, safe and effective.

The invention relates to the field of an electric system high voltage technique and an equipment manufacturing technique, in particular to an outdoor compound insulation high-voltage anti-thunder support. The outdoor compound insulation high-voltage anti-thunder support comprises an insulation pipe, an upper metal flange is arranged at the upper end of the insulation pipe, a lower metal flange isarranged at the lower end of the insulation pipe, the insulation pipe is filled with a metal oxide valve block set, a silicone rubber sheath sleeves the insulation pipe, and umbrella skits are arranged on the silicone rubber sheath. By means of the outdoor compound insulation high-voltage anti-thunder support, the insulating and supporting performance of a conventional high-voltage insulation support is integrally combined with the anti-thunder performance of a metal oxide lightning arrester, the insulating level is increased, the anti-thunder effect is also good, the outdoor compound insulation high-voltage anti-thunder support can be installed at an outdoor transformer substation bus or incoming line, the site space can be saved, compact arrangement of electrical equipment is facilitated, the electrical installation distance between the support and protected equipment can be shortened, the anti-thunder level of a transformer substation is effectively increased, the power supply reliability is improved, and a series of economic loss when the equipment is damaged due to insulation breakdown is reduced.

The invention is applicable to the technical field of surge protectors, and provides a high-voltage lightning-proof surge suppression circuit, a device and a power adapter, comprising a varistor, a discharge tube, a high-voltage capacitor, an inductance and a resistor. One end of the varistor is connected with a fire wire or a neutral wire, and the other end is grounded through the discharge tube.The high-voltage capacitor is connected in parallel at both ends of the varistor, and the inductance and the resistor are connected in series in parallel at both ends of the discharge tube. The invention can be used under the condition of withstanding voltage requirement of 1500VAC, and can discharge discharge surge current when surge peak voltage is 1600V, and residual voltage is lower than 1.3KV; It can also be used under the condition of withstand voltage requirement of 3000VAC, and discharge surge current can be discharged when surge peak voltage is 3600V, and residual voltage is lower than 3KV. It can also be used under the condition of withstand voltage requirement of 3000VAC. Under the condition of withstand voltage requirement of 1500VAC or 3000VAC, the current is lower than 5mAand no flashover occurs; And meets the basic insulation requirements, and the equivalent resistance is greater than 10M ohm under the condition of 500VAC.