CN209072063U - A kind of novel lightning protection overvoltage crowbar and protective device - Google Patents
A kind of novel lightning protection overvoltage crowbar and protective device Download PDFInfo
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- CN209072063U CN209072063U CN201821459904.0U CN201821459904U CN209072063U CN 209072063 U CN209072063 U CN 209072063U CN 201821459904 U CN201821459904 U CN 201821459904U CN 209072063 U CN209072063 U CN 209072063U
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Abstract
The utility model discloses a kind of novel lightning protection overvoltage crowbars and protective device, protecting circuit includes the first piezoresistive wafer, second piezoresistive wafer, Transient Suppression Diode, posive temperature coefficient thermistor piece, gas-discharge tube and leading-out terminal, first piezoresistive wafer is connected with gas-discharge tube, posive temperature coefficient thermistor piece is connected with Transient Suppression Diode, it connects again with the second piezoresistive wafer after two series arms are in parallel, form a single port combinational circuit, wherein, first piezoresistive wafer and the performance of gas-discharge tube tolerance surge impact are above the performance of the second piezoresistive wafer tolerance surge impact；At least one in two leading-out terminals of single port combinational circuit is the thermally conductive end of low thermal resistance, thermal coupling has the thermally conductive end of the low thermal resistance respectively for the posive temperature coefficient thermistor piece and/or the second varistor on piece, and the Transient Suppression Diode can replace with Zener diode or voltage switch type element.
Description
Technical field
The utility model relates to field of power supplies, in particular to a kind of novel lightning protection overvoltage crowbar and protective device.
Background technique
A kind of low-voltage electrical apparatus of the Surge Protector (abbreviation SPD) as standard, is widely used in low pressure electric line,
The surge as caused by thunder and lightning etc. occurred in route effectively can be absorbed and be inhibited, to improvement grid power transmission quality, be protected
Card electrical appliance has safely apparent effect.
The core component of SPD is Surge suppression element, and the most commonly used is based varistor chips.Due to electric line
Transmission range is longer, but be easy to be exposed to it is outdoor, compared to indoor electric appliance equipment be easier by high-energy surge pulse, in SPD
Phase projected life in, based varistor chip be easier by be more than rated specification high-energy surge repeat impact,
Cause the deterioration failure of varistor.Since varistor is short circuit failure mode, once breakdown failure, will cause supply lines
Road short trouble, breakdown point will appear burst, smolder, arcing, it is serious when in addition will cause catching fire.
The schematic diagram of most common ameliorative way is shown in attached drawing 1, on two end electrodes of based varistor chip 1,
It is respectively welded and connects a piece of conductive and all excellent heating conduction scale copper electrode 2, scale copper electrode 2 is prefabricated with leading-out terminal
3, scale copper electrode 2 also forms thermal coupling with based varistor chip 1 while playing the role of conductive electrode, and energy will be pressure-sensitive
The heat that resistor ceramic chip 1 generates is transmitted on leading-out terminal 3.It is welded on a leading-out terminal 3 with low-melting alloy 5 wherein
It connects a piece of elastic sheet metal 4 and forms overheat disconnector.When based varistor chip 1, which is deteriorated to leakage current, enters milliampere grade,
Accelerated deterioration area is initially entered, leakage current can make the fever of based varistor chip 1 that leakage current be promoted to further increase, and accelerate
Based varistor chip 1 generates heat, and will finally make 1 thermal breakdown of based varistor chip.When heat reaches low-melting alloy 5
When fusing-off temperature, disconnector action power dump is overheated, so that based varistor chip 1 is exited power grid before puncture short, reaches
The purpose of protection is arrived.The program can turn the failure mode of most based varistor chip 1 from pernicious short-circuit mode
It is changed to the open circuit mode for influencing very little, greatly improves the safety of SPD.
But still there is also some defects for the program, since the movement of overheat disconnector needs to be delayed by several seconds the time, and
1 leakage current of based varistor chip enters milliampere grade and starts accelerated deterioration adstante febre, and the defect inside porcelain body is very serious
, there is the defect of partial chip seriously to arrive very short to the time of puncture short from starting to generate heat, heat also has little time to be transmitted to
Hot disconnector melts low-melting alloy 5, and short circuit accident just has occurred.Another much situation is exactly when pressure-sensitive electricity
Resistance ceramic chip 1 is deteriorated to when closing on accelerated deterioration area, and at this moment the leakage current of based varistor chip 1 is also less than milliampere grade,
It can also maintain thermostabilization, additionally it is possible to work is maintained under the operating voltage of power grid, but its pressure sensitive voltage value at this time has compared
Initial value when just starting to come into operation has apparent sharp fall, the anti-surge punching of based varistor chip 1 at this moment
The ability hit is very fragile, and an energy is not counting it can directly be punctured or close to breakdown by too big surge, at this time
Its puncture short speed is also that too fastly, overheat disconnector has little time response action and do not have protective effect.
Utility model content
The purpose of the utility model is to overcome the above-mentioned deficiencies in the presence of the prior art, provide a kind of novel lightning protection
Overvoltage crowbar and protective device.
In order to achieve the above-mentioned object of the invention, the utility model provides following technical scheme:
A kind of novel lightning protection overvoltage crowbar, including the first piezoresistive wafer, the second piezoresistive wafer, transient state inhibit
Diode, posive temperature coefficient thermistor piece, gas-discharge tube and leading-out terminal, first piezoresistive wafer and the gas
Discharge tube series connection, the posive temperature coefficient thermistor piece are connected with the Transient Suppression Diode, described two series arms
It connects again with second piezoresistive wafer after parallel connection, forms a single port combinational circuit, wherein first varistor
Piece and the performance of gas-discharge tube tolerance surge impact are above the performance of the second piezoresistive wafer tolerance surge impact；Institute
Stating at least one in two leading-out terminals of single port combinational circuit is the thermally conductive end of low thermal resistance, the thermally conductive end of low thermal resistance
Be thermally coupled to each other with one of them in second piezoresistive wafer, the posive temperature coefficient thermistor piece or with two it is same
When be thermally coupled to each other.In use, in the thermally conductive end connection overheat disconnector of the low thermal resistance, the posive temperature coefficient thermistor
The Curie point of piece is higher than the operating temperature of the overheat disconnector.
The principle Analysis of the utility model is as follows:
It is to absorb surge arteries and veins by the series loop that the first piezoresistive wafer, gas-discharge tube, the second piezoresistive wafer form
The main channel of punching, when not having surge pulse, varistor is in high-impedance state, and gas-discharge tube is in an off state, the branch
Road is in open-circuit condition.When surge arrives, varistor is in low resistive state, and gas-discharge tube is on state, surge energy by
It releases in this circuit.At this point, the pressure drop on gas-discharge tube is very low negligible.The voltage-limiting protection level of SPD is regarded as
The residual voltage value of first piezoresistive wafer and the sum of the residual voltage value of the second piezoresistive wafer.After surge disappears, piezoresistive wafer is returned
To high-impedance state, pincers has broken the afterflow of gas-discharge tube, and gas-discharge tube is made to return to off-state.In order to ensure in surge channel
Component deterioration will since the second piezoresistive wafer, tolerance surge impact capacity selection on, the first pressure-sensitive electricity should be followed
The tolerance of piece and gas-discharge tube is hindered greater than the principle of the second piezoresistive wafer, has worked as the second piezoresistive wafer to reach
Significant deterioration, when starting to start Thermal protection circuit, the first piezoresistive wafer and the also substantially intact purpose of gas-discharge tube.
Another circuit is to be connected by the second piezoresistive wafer, Transient Suppression Diode with posive temperature coefficient thermistor piece
Made of Thermal protection branch, and overheat disconnector is connected to by thermally conductive end.When the intact no surge of element, due in height
Not on-state is hindered, the leakage current for flowing through Thermal protection branch is minimum (microampere order), and Thermal protection branch does not generate heat.Even if when surge comes
Temporarily, since the posive temperature coefficient thermistor piece being serially connected in branch still has tens Dao several hundred ohm resistance value at normal temperature,
And the series arm of the first piezoresistive wafer and gas-discharge tube connected in parallel its dynamic electric in the case where absorbing surge on state
Resistance can be several ohm down to zero point, and major part surge current absolutely passes through from this dynamic low-resistance branch, and positive temperature coefficient temperature-sensitive
Resistor disc and the voltage at Transient Suppression Diode series arm both ends are also limited in the residual voltage value of the first piezoresistive wafer, flow through
The surge current of Thermal protection branch at most namely pacifies times grade with this condition, the heat that thermistor generates in a short period of time
Measure minimum and surge just disappears, Thermal protection branch can because generate heat it is faint due to be failure to actuate.
The Analysis of Failure Mechanism of the utility model is as follows:
When the second piezoresistive wafer significantly deteriorates, pressure sensitive voltage value declines to a great extent, the pressure sensitive voltage of the second piezoresistive wafer
After value is superimposed with the turn-on voltage of Transient Suppression Diode, when being still below network operation voltage peak, in Thermal protection branch
Transient Suppression Diode is converted on state by off state rapidly, and the electric current for flowing through Thermal protection branch increases sharply, and reaches
After the action current of posive temperature coefficient thermistor, thermistor is brought rapidly up, and the resistance value of posive temperature coefficient thermistor piece is fast
Speed rises, and reduces the electric current for flowing through Thermal protection branch quickly, and finally reach thermal balance above Curie point, heat can
It is transmitted to overheat disconnector with stabilization, constantly from thermally conductive end, temperature can achieve near Curie temperature, overheat disconnector
Operating temperature is set below at Curie temperature, can reliably disengaging be acted, so that the SPD deteriorated be made to be detached from grid line
Road.The technical program can make the SPD after most deteriorate exit power grid in this safe mode.
For those much special circumstances, i.e., when the second piezoresistive wafer deteriorates to a certain extent or has located
When accelerated deterioration area, its anti-impulse ability has declined to a great extent at this time, and stronger surge of energy can be
It directly punctures or close breakdown.When surge disappear after, due to resistance to surge impact capacity it is stronger and substantially intact than it first
Piezoresistive wafer still is able to the follow current of the disconnected gas-discharge tube of pincers, and gas-discharge tube can still return to off-state, at this time
Network operation voltage still will be applied to Thermal protection branch both ends, since the conducting voltage of Transient Suppression Diode is set as being less than
Power grid crest voltage, still being able to turnover is on state, and the electric current increased rapidly still can make posive temperature coefficient thermistor
It is rapidly heated and reaches thermal balance.It still can generate heat to Curie point and make to overheat disconnector movement, and overheat disconnector is just
Meeting action power dump, makes the SPD of damage safely exit power grid.Since overheat disconnector is generally provided with positioning indicator
Or electricity, sound, light warning device, it will soon be found, maintenance personal replaces in which can be convenient, and has reached safe handling
Purpose.To substantially increase the safety and reliability of SPD, the electrical equipment crash rate connected on route also will significantly
Reduce.
Bipolarity Transient Suppression Diode is used when for communication environment, can use unipolarity pipe under DC environment.Institute
State the breakdown voltage value V of Transient Suppression DiodeBRLess than the network operation voltage peak accessed, second piezoresistive wafer
Maximum continuous direct-current working volts value and the Transient Suppression Diode maximum reverse operating voltage value VRWMThe sum of be greater than institute
The network operation voltage peak of access.
Further, the posive temperature coefficient thermistor piece can replace with the resistance of linear feature, linear special
The electric current of the resistance of sign is substantially proportional to voltage, i.e., its characteristic equation is mainly linear homogeneous, and defers to Ohm's law.
The resistance of linear feature can also play the role of following in Thermal protection branch: first is that metering function, when described second pressure-sensitive
After resistor disc accelerated deterioration even puncture short, the resistance of linear feature can pacify the current limit in Thermal protection branch
Within total head, it not will cause the lightning protection overvoltage crowbar short circuit and burn；Second is that heating functioin, the electric current within safety value is held
The continuous resistance by second piezoresistive wafer and linear feature, which will be such that they are warming up to, makes to overheat disconnector movement, together
Sample can achieve the purpose of Thermal protection.To reach said effect, the current value of Thermal protection branch in the most adverse case (second
Piezoresistive wafer puncture short) it is advisable for tens milliamperes to several amperes, the resistance value of the resistance of corresponding linear feature is several
Kilohm to tens ohm.
In the present invention, the resistance of linear feature both includes linear resistance, also allow containing it is some it is non-linear at
Divide (non-linear component is smaller, mainly still embodies Ohm's law feature), but power is required to want sufficiently large, pressure resistance is wanted
It is sufficiently high, at least to adhere to that failure cannot be damaged before overheating disconnector movement.
Preferably, the Transient Suppression Diode can replace with other voltage limiting type elements, such as Zener diode,
When not having surge, voltage limiting type element has high impedance, but with the raising of surge current and voltage, voltage limiting type member
The impedance of part is by the reduction of duration.Using the bipolarity Zener diode of back-to-back connection, direct current ring when for communication environment
Unipolarity pipe, the voltage of voltage regulation value V of the Zener diode can be used under borderZLess than the network operation Voltage Peak accessed
Value.The reverse snapback voltage value of the maximum of second piezoresistive wafer continuous direct-current working volts value and the Zener diode
VRThe sum of be greater than accessed network operation voltage peak.
The voltage limiting type element (including Transient Suppression Diode and Zener diode etc.) for being serially connected in Thermal protection branch is main
Play two, first is that adjusting the sensitivity of Thermal protection branch starting；It is accessed second is that adjusting the tolerance of single port combinational circuit
The ability of voltage ripple of power network.The turn-on voltage of voltage limiting type element selects lower, and Thermal protection branch starts more early,
Second piezoresistive wafer is not deteriorated to also close to just movement is detached from power grid when breakdown.But the conducting voltage of voltage limiting type element
Value can not be selected excessively high, once choosing value be higher than power grid crest voltage after, even if the second piezoresistive wafer deteriorated breakdown it is short
Lu Liao, voltage limiting type element can also maintain off state to be not turned on, and Thermal protection branch is just passivated and fails.
Since the maximum continuous work voltage value in single port combinational circuit is continuous by the maximum of the second piezoresistive wafer
Operating voltage value and the maximum of voltage limiting type element are not turned on the sum of voltage value to determine, and the second piezoresistive wafer is in electricity
It gushes and absorbs on major loop, pressure sensitive voltage value (being proportional to maximum continuous work voltage value) should not select get Tai Gao, in order to avoid increase residual
Pressure value influences level of protection.Therefore, the maximum of voltage limiting type element can be not turned on voltage value and selects Gao Yidian, to be resistant to
Access the erratic fluctuations of network operation voltage.
Due to the series connection Thermal protection branch of the posive temperature coefficient thermistor piece when surge is impacted and voltage limiting type element
Impedance is higher, and both ends are protected by the residual voltage of the first piezoresistive wafer again, so hardly by surge damage, positive temperature coefficient
The diameter of thermosensitive resistor film can select it is a little bit smaller, as long as can ensure that the heat generated is enough to make to overheat the premise of disconnector movement
Under, a little bit smaller action current that can make thermistor of diameter is a little bit smaller, smaller to the impact of voltage limiting type element.And
Choosing can be considered greatly a bit in the power of voltage limiting type element, although being possible in the moment that Thermal protection starts conducting turnover by mistake
Big-movement electric current puncture short, but do not influence the effect of heat protection function, or even positive temperature coefficient temperature-sensitive can also be made electric at all
Resistance quickly reaches thermal balance.Only power choosing is big a little can generate mechanical damage to avoid the rush of current of turnover moment, from
And influence the reliability of circuit.
Preferably, the Transient Suppression Diode can replace with voltage switch type element, when there is no surge, the voltage
Switching mode element has high impedance, and when there is surge, the voltage switch type element can be immediately converted as Low ESR.At this point, this
The Analysis of Failure Mechanism of utility model is as follows:
When the second piezoresistive wafer does not deteriorate or pressure sensitive voltage value is deteriorated to not yet lower than accessed network voltage
When a certain ratio of peak value, surge each time is arrived, although voltage switch type element will be connected, the second varistor at this time
Piece can also clamp the follow current of power-off net, and after surge disappears, voltage switch type element can return to off-state, Thermal protection branch
Road is of short duration conducting, and the shortage of heat of generation is so that thermistor temp is increased significantly.When pressure sensitive voltage value is further bad
After change, the impact of surge next time is possible to clamp the power grid follow current after continuous voltage switch type element conductive.Voltage switch
Type element does not return to off-state, and the electric current for flowing through Thermal protection branch has been more than the movement electricity of posive temperature coefficient thermistor
Stream, makes it be rapidly reached the heat balance point of near Curie temperature, and heat can be transmitted to overheat from thermally conductive end at leisure and be detached from
Device makes overheat disconnector reliably act disengaging, the SPD deteriorated is made safely to exit power grid.
For those much special circumstances, i.e., when the second piezoresistive wafer deteriorates to a certain extent or has located
When accelerated deterioration area, its anti-impulse ability has declined to a great extent at this time, and stronger surge of energy can be
It punctures or close to breakdown, it also loses the follow current for clamping and flowing through voltage switch type element in disconnected Thermal protection branch at this time
Ability.After surge disappears, since resistance to surge impact capacity first piezoresistive wafer stronger and substantially intact than it still can
Enough follow currents for clamping disconnected gas-discharge tube, gas-discharge tube can still return to off-state.Network operation voltage is still at this time
Thermal protection branch both ends will be applied to, and voltage switch type element remains on state, posive temperature coefficient thermistor is just
It can be rapidly heated and reach thermal balance near Curie temperature, to make to overheat disconnector action power dump, make the SPD peace of damage
Power grid is released entirely.
The breakdown turn-on voltage for being serially connected in the voltage switch type element in Thermal protection branch will be with the first piezoresistive wafer
Pressure sensitive voltage value it is substantially uniform.If that chooses is too high, biggish surge is needed just to have foot by the first piezoresistive wafer
Enough high residual voltage values make its breakdown conducting, influence the sensitivity of Thermal protection branch starting；If that chooses is too low, itself and the can be made
The sum of maximum continuous work voltage value of two piezoresistive wafers reduces, and influences single port combined finger and is resistant to accessed network operation
The ability of spread of voltage fluctuation.Due to the surge current very little in thermistor and voltage switch type element series arm, electricity
The type element of compressing switch can choose the lesser miniaturized element of through-current capacity and be sufficient.
Preferably, the voltage switch type element can be chosen for gas-discharge tube (hereinafter referred to as second gas discharge tube,
To and be distinguished in circuit with the concatenated gas-discharge tube of the first piezoresistive wafer).Second piezoresistive wafer it is pressure-sensitive
Voltage value is greater than the 50% of accessed network operation voltage peak.
Preferably, the pressure sensitive voltage value of first piezoresistive wafer is the 0.5 of accessed network operation voltage peak
To 1 times, the pulse breakdown voltage of the gas-discharge tube is greater than accessed network operation voltage peak.It can guarantee second
It, only can also be by the follow current of gas-discharge tube by the first piezoresistive wafer in the case where the thorough puncture short of piezoresistive wafer
Pincers is disconnected, and gas-discharge tube is made to return to off-state, improves the safety of single port combinational circuit.When the pressure of the first piezoresistive wafer
When quick voltage value selects too low, it cannot be guaranteed that in the case reliably pincers break gas-discharge tube follow current；Select excessively high
When, the limitation voltage indexes of single port over-voltage protector can be improved, level of protection is influenced.
Specifically, the pressure sensitive voltage value of first piezoresistive wafer is 156V-311V, the pulse of the gas-discharge tube
Breakdown voltage is greater than 311V, when can be suitable for access 220V power grid；Alternatively, the pressure sensitive voltage of first piezoresistive wafer
Value is 78V-156V, and the pulse breakdown voltage of the gas-discharge tube is greater than 156V, when can be suitable for access 110V power grid；
Alternatively, the pressure sensitive voltage value of first piezoresistive wafer is 269V-537V, the pulse breakdown voltage of the gas-discharge tube
Greater than 537V, when can be suitable for access 380V power grid.
Preferably, between second piezoresistive wafer and the posive temperature coefficient thermistor piece by conduction material into
Row heat transfer.The heat generated when second piezoresistive wafer can be started accelerated deterioration by conduction material is conducted to institute
Posive temperature coefficient thermistor piece is stated, so that the resistance value of posive temperature coefficient thermistor piece be made to rise, shortens positive temperature coefficient
Thermosensitive resistor film reaches the time of Curie point, and can reduce its action current.Realize that the substance of this heat conduction has
Various ways, such as all interconnectors can be designed as low thermal resistance conducting wire, the second piezoresistive wafer can be generated
Heat is transmitted to the entire novel lightning protection overvoltage crowbar, also just contains the posive temperature coefficient thermistor
Piece.One electrode surface of the posive temperature coefficient thermistor piece can also be projected in one of second piezoresistive wafer
On electrode surface, centre is inserted into a piece of conduction material gasket and is again sequentially fixed at them together, what the second piezoresistive wafer generated
Heat can be conducted to posive temperature coefficient thermistor piece by conduction material gasket.Conduction material gasket can be oxidation
Aluminium potsherd or other insulating materials, it might even be possible to be voltage-sensitive ceramic piece, if not by Transient Suppression Diode short circuit or
Influencing its work can.
Preferably, the impact resistance current rating of first piezoresistive wafer and gas-discharge tube is above described second
The impact resistance current rating of piezoresistive wafer.
Preferably, the first piezoresistive wafer electrode surface area of first piezoresistive wafer is greater than the described second pressure-sensitive electricity
Hinder the second piezoresistive wafer electrode surface area of piece.Measuring piezoresistive wafer tolerance surge impact capacity has multinomial technical indicator,
It is main to have: dash current Iimp, current waveform is 10/350 μ s；Maximum discharge current Imax, current waveform is 8/20 μ s；Energy
Tolerance, current waveform are 2ms square wave；Rush of current stability is exactly with 8/20 μ s waveform nominal discharge current In repeated impacts
The number etc. being resistant to.Under identical geometric dimension, by adjusting ceramic formula or technological parameter can optimize one of them or
Multiple parameters index, but want General Promotion or relatively difficult.But these technical indicators are all and varistor plate electrode
Area is directly proportional, therefore, as long as increasing the area of the first varistor plate electrode under the conditions of same process, so that it may ensure to be resistant to
Surge impact capacity is comprehensively more than the second piezoresistive wafer.
Preferably, the nominal diameter of first piezoresistive wafer is nominal straight at least more than second piezoresistive wafer
One sequence number of diameter.Since the diameter of flanking sequence number is than about 1.25 times, they are resistant to the parameter difference of surge impact capacity
About 1.5 times, as long as the second piezoresistive wafer is designed to match with application environment, then the first piezoresistive wafer belongs to
Redundancy Design, crash rate will be reduced than the second piezoresistive wafer in the order of magnitude, so that it may which guarantee makes the second piezoresistive wafer first
Deterioration.
The invention also discloses a kind of novel lightning protection over-pressure safety device, the novel lightning protection overvoltage protection dress
It sets and uses the novel lightning protection overvoltage crowbar of any above-mentioned one kind.Specifically, one of second piezoresistive wafer
Be welded and connected with the Transient Suppression Diode and the gas-discharge tube on electrode surface, the Transient Suppression Diode it is another
It is connected with the posive temperature coefficient thermistor piece on a electrode, the posive temperature coefficient thermistor piece and gas-discharge tube
Be connected separately with two electrode surfaces of first piezoresistive wafer on another electrode, second piezoresistive wafer and/or
The posive temperature coefficient thermistor on piece is also welded with the thermally conductive end of low thermal resistance, to realize the thermal coupling of element.The transient state
Inhibit diode that can replace with voltage switch type element, the connection of element preferentially selects directly to weld between electrode surface, as far as possible
Less with internal connecting lead wire or conducting bracket.
Preferably, the first piezoresistive wafer, second piezoresistive wafer, the Transient Suppression Diode (or Zener two
Pole pipe or voltage switch type element), the posive temperature coefficient thermistor piece, the gas-discharge tube be packaged as a whole, with exhausted
Remaining surface in addition to two leading-out terminals is wrapped up in envelope by edge material.
Preferably, the thermally conductive end of low thermal resistance with thermally conductive function has foot using excellent materials of heating conductions such as copper
Enough big cross-sectional areas.And pyrotoxin (piezoresistive wafer or positive temperature coefficient temperature-sensitive are connected to using thermal couplings modes such as welding
On resistor disc), and distance of the thermally conductive end away from pyrotoxin will as far as possible it is short, to obtain minimum thermal resistance, guarantee has enough
Heat is transmitted to overheat disconnector.
Compared with prior art, the utility model has the beneficial effects that
The utility model is equipped with simultaneously to be composed in series by the first piezoresistive wafer, gas-discharge tube, the second piezoresistive wafer
Absorption surge pulse main channel, and by the second piezoresistive wafer, Transient Suppression Diode (or Zener diode, or electricity
The type that compresses switch element), the Thermal protection branch that is connected in series of posive temperature coefficient thermistor piece, and two branch circuit parallel connections.In routine
Under failure conditions and special failure conditions, the overheat disconnector of SPD can action power dump so that SPD is finally with mould of opening a way
Formula exits circuit, relative to traditional short-circuit mode, greatly improves the safety of SPD, it is therefore prevented that generates when short circuit breakdown
Smolder, arcing, even catching fire serious accident.Meanwhile overheat the positioning indicator that is equipped with of disconnector or electricity,
Sound, light warning device, so that the SPD of damage will soon be found, maintenance personal replaces in which can be convenient, and has reached peace
The purpose entirely used, to substantially increase the safety and reliability of SPD, the electrical equipment crash rate connected on route also will
Significantly reduce.
In addition, the voltage limiting type element (or voltage switch type element) for being serially connected in Thermal protection branch mainly plays two works
With first is that adjusting the sensitivity of Thermal protection branch starting；Second is that adjusting single port combinational circuit is resistant to accessed network voltage wave
Dynamic ability.
The gas-discharge tube being serially connected in main channel has primarily served the pressure sensitive voltage of reduction by first piezoresistive wafer
The effect of value reduces the limitation voltage indexes of single port over-voltage protector, reduces the residual voltage of the first piezoresistive wafer, so as to
The preferably access electric appliance on protection power grid.
Detailed description of the invention:
Fig. 1 is the schematic illustration of improvement plan one described in the prior art.
It is marked in Fig. 1: 1- based varistor chip, 2- scale copper electrode, 3- leading-out terminal, 4- elastic sheet metal, 5-
Low-melting alloy.
Fig. 2 is the schematic diagram of the novel lightning protection overvoltage crowbar of one kind described in the utility model embodiment 1.
Fig. 3 is the schematic diagram of the novel lightning protection overvoltage crowbar of one kind described in the utility model embodiment 2.
Fig. 4 is the schematic diagram of the novel lightning protection overvoltage crowbar of one kind described in the utility model embodiment 3.
Fig. 5 is the part drawing of the novel lightning protection over-pressure safety device of one kind described in the utility model embodiment 4.
Fig. 6 is the assembling figure of the novel lightning protection over-pressure safety device of one kind described in the utility model embodiment 4.
It is marked in Fig. 2-Fig. 6: the first piezoresistive wafer of 1-, 11- the first piezoresistive wafer electrode surface, the second varistor of 2-
Piece, 21- the second piezoresistive wafer electrode surface, 3- Transient Suppression Diode, 4- posive temperature coefficient thermistor piece, 5- gas discharge
Pipe, 6- leading-out terminal.
Specific embodiment
The utility model is described in further detail below with reference to test example and specific embodiment.But it should not be by this
The range for being interpreted as the above-mentioned theme of the utility model is only limitted to embodiment below, all to be realized based on the content of the present invention
Technology belongs to the scope of the utility model.
Embodiment 1
As shown in Fig. 2, a kind of novel lightning protection overvoltage crowbar, including the first piezoresistive wafer 1, the second varistor
Piece 2, Transient Suppression Diode 3, posive temperature coefficient thermistor piece 4, gas-discharge tube 5 and leading-out terminal 6, described first is pressure-sensitive
Resistor disc 1 is connected with the gas-discharge tube 5, and the posive temperature coefficient thermistor piece 4 is gone here and there with the Transient Suppression Diode 3
Connection connects again with second piezoresistive wafer 2 after described two series arms are in parallel, forms a single port combinational circuit,
Wherein, the performance that first piezoresistive wafer 1 and gas-discharge tube 5 are resistant to surge impact is above second varistor
Piece 2 is resistant to the performance of surge impact.
Two leading-out terminals 6 of the single port combinational circuit are the thermally conductive end of low thermal resistance, the thermally conductive end of low thermal resistance
Head is thermally coupled to each other with second piezoresistive wafer 2, meanwhile, the thermally conductive end of low thermal resistance and the positive temperature coefficient temperature-sensitive
Resistor disc 4 is thermally coupled to each other.
The pressure sensitive voltage value of first piezoresistive wafer 1 is 0.5 to 1 times of accessed network operation voltage peak；
The turn-on voltage of the Transient Suppression Diode 3 is less than accessed network operation voltage peak；Second varistor
The maximum continuous work voltage value of piece 2 and the maximum of the Transient Suppression Diode 3 be not turned on the sum of voltage value be greater than accessed
Network operation voltage peak.
The Transient Suppression Diode 3 can replace with Zener diode or voltage switch type element, the voltage switch
Type element can be chosen for second gas discharge tube.
Embodiment 2
As shown in figure 3, the present embodiment the difference from embodiment 1 is that, two exits of the single port combinational circuit
Sub 6 only ones are the thermally conductive end of low thermal resistance, and the thermally conductive end of low thermal resistance is thermally coupled to each other with second piezoresistive wafer 2.
Embodiment 3
The present embodiment the difference from embodiment 1 is that, two 6 only ones of leading-out terminal of the single port combinational circuit
For the thermally conductive end of low thermal resistance, the thermally conductive end of low thermal resistance and the posive temperature coefficient thermistor piece 4 are thermally coupled to each other (such as
Shown in Fig. 4).
Embodiment 4
As shown in Fig. 5-Fig. 6, a kind of novel lightning protection over-pressure safety device, one of second piezoresistive wafer 2
The Transient Suppression Diode 3 and the gas-discharge tube 5 are connected on two piezoresistive wafer electrode surfaces 21, the transient state inhibits
The posive temperature coefficient thermistor piece 4, the posive temperature coefficient thermistor piece are connected on another electrode of diode 3
4 another electrode is connected with a first piezoresistive wafer electrode surface 11 of first piezoresistive wafer 1, the gas
Another electrode of discharge tube 5 connects another the first piezoresistive wafer electrode surface 11 of first piezoresistive wafer 1.It is described
Leading-out terminal 6, wherein at least one are also welded on second piezoresistive wafer 2 and/or the posive temperature coefficient thermistor piece 4
A is the thermally conductive end of low thermal resistance.The Transient Suppression Diode 3, the posive temperature coefficient thermistor piece 4, the gas discharge
Pipe 5 is installed between second piezoresistive wafer 2 and first piezoresistive wafer 1, finally again by the first varistor
Piece 1, second piezoresistive wafer 2, the Transient Suppression Diode 3, the posive temperature coefficient thermistor piece 4, the gas
Body discharge tube 5 is packaged as a whole.
Specifically, the pressure-sensitive tile (40K241x2) of square of the first piezoresistive wafer 1 selection two panels nominal diameter 40mm
For equivalent substitution to reduce mounting area, which is that the industry is the routine side for reducing mounting area and using after parallel connection
Formula can also directly adopt the pressure-sensitive tile of rectangle certainly, and pressure sensitive voltage is 240 volts, and maximum discharge current Imax is 80KA；
Second piezoresistive wafer 2 selects the pressure-sensitive tile 40K331 of square of nominal diameter 40mm, and pressure sensitive voltage is 330 volts, and maximum is put
Electric current Imax is 40KA；Transient Suppression Diode 3 selects VRWM=200V, VBRThe axial lead plastic packaging transient state of=220V inhibits
Diode, the maximum discharge current Imax of gas-discharge tube 5 are 50KA, 450 volts of pulse breakdown voltage；Positive temperature coefficient temperature-sensitive electricity
4 160 DEG C of Curie point of selection of resistance, 150 ohm of room temperature resistance value, the disk of diameter 10mm.Reference selection is suitble in 220 couchers
It works in frequency power grid, the operating temperature of overheat disconnector matched with its is 120 DEG C.
Package unit is connected on 220 coucher frequency routes, and applies the surge repeated impacts of In=20KA, the 98th punching
Disconnector movement is overheated after hitting, and is cooled to and is tested the pressure sensitive voltage value of the second piezoresistive wafer 2 after room temperature to have deteriorated be 0 volt,
To puncture short, and the first piezoresistive wafer 1 is still 238 volts, is remained unchanged substantially.
Preferably, the Transient Suppression Diode 3 can replace with Zener diode or voltage switch type element, the electricity
The type element of compressing switch can be chosen for second gas discharge tube.
Embodiment 5
The present embodiment and the difference of embodiment 4 are that second piezoresistive wafer 2 and the positive temperature coefficient temperature-sensitive are electric
Heat transfer is carried out by conduction material between resistance piece 4.Such as all interconnectors 6 can be designed as low thermal resistance conducting wire,
The heat that second piezoresistive wafer 2 generates can be transmitted to the entire novel lightning protection over-pressure safety device, also just comprising
The posive temperature coefficient thermistor piece 4.One electrode surface of the posive temperature coefficient thermistor piece 4 can also be projected
On an electrode surface of second piezoresistive wafer 2, centre is inserted into a piece of conduction material gasket and again successively fixes them
Together, the heat that the second piezoresistive wafer 2 generates can be conducted to positive temperature coefficient temperature-sensitive electricity by conduction material gasket
Hinder piece 4.Conduction material gasket can be alumina ceramic plate or other insulating materials, it might even be possible to be voltage-sensitive ceramic piece, only
Otherwise by 3 short circuit of the Transient Suppression Diode or influence that it works can.
Above embodiments are only to illustrate the utility model and not limit technical solution described in the utility model, to the greatest extent
Pipe this specification has been carried out detailed description to the utility model referring to above-mentioned each embodiment, but the utility model not office
It is limited to above-mentioned specific embodiment, therefore any pair of the utility model is modified or equivalent replacement；And all do not depart from it is practical
The technical solution and its improvement of novel spirit and scope, should all cover in the scope of the claims of the utility model.
Claims (10)
1. a kind of novel lightning protection overvoltage crowbar, including the first piezoresistive wafer (1), the second piezoresistive wafer (2), transient state
Inhibit diode (3), posive temperature coefficient thermistor piece (4), gas-discharge tube (5) and leading-out terminal (6), which is characterized in that
First piezoresistive wafer (1) is connected with the gas-discharge tube (5), the posive temperature coefficient thermistor piece (4) and institute
Transient Suppression Diode (3) series connection is stated, is connected again with second piezoresistive wafer (2) after described two series arms are in parallel,
Form a single port combinational circuit, wherein first piezoresistive wafer (1) and gas-discharge tube (5) tolerance surge impact
Performance be above the performance of second piezoresistive wafer (2) tolerance surge impact；
At least one in two leading-out terminals (6) of the single port combinational circuit is the thermally conductive end of low thermal resistance, the positive temperature
Thermal coupling has the thermally conductive end of the low thermal resistance respectively on degree coefficient resistance piece (4) and/or the second piezoresistive wafer (2).
2. the novel lightning protection overvoltage crowbar of one kind according to claim 1, which is characterized in that the transient state inhibits two
Pole pipe (3) can replace with Zener diode or voltage switch type element.
3. the novel lightning protection overvoltage crowbar of one kind according to claim 2, which is characterized in that the voltage switch type
Element is gas-discharge tube.
4. the novel lightning protection overvoltage crowbar of one kind according to claim 1, which is characterized in that the first pressure-sensitive electricity
The pressure sensitive voltage value of resistance piece (1) is 0.5 to 1 times of accessed network operation voltage peak；The arteries and veins of the gas-discharge tube (5)
Breakdown voltage is rushed greater than accessed network operation voltage peak.
5. the novel lightning protection overvoltage crowbar of one kind according to claim 1, which is characterized in that the first pressure-sensitive electricity
The pressure sensitive voltage value for hindering piece (1) is 156V-311V, and the pulse breakdown voltage of the gas-discharge tube (5) is greater than 311V, can
When suitable for access 220V power grid；
Alternatively, the pressure sensitive voltage value of first piezoresistive wafer (1) is 78V-156V, the pulse of the gas-discharge tube (5)
Breakdown voltage is greater than 156V, when can be suitable for access 110V power grid；
Alternatively, the pressure sensitive voltage value of first piezoresistive wafer (1) is 269V-537V, the pulse of the gas-discharge tube (5)
Breakdown voltage is greater than 537V, when can be suitable for access 380V power grid.
6. the novel lightning protection overvoltage crowbar of -5 any described one kind according to claim 1, which is characterized in that described second
Heat transfer is carried out by conduction material between piezoresistive wafer (2) and the posive temperature coefficient thermistor piece (4).
7. the novel lightning protection overvoltage crowbar of -5 any described one kind according to claim 1, which is characterized in that described first
First piezoresistive wafer electrode surface (11) area of piezoresistive wafer (1) is greater than the second pressure of second piezoresistive wafer (2)
Quick resistor disc electrode surface (21) area.
8. the novel lightning protection overvoltage crowbar of -5 any described one kind according to claim 1, which is characterized in that described first
One sequence number of nominal diameter of the nominal diameter of piezoresistive wafer (1) at least more than second piezoresistive wafer (2).
9. the novel lightning protection overvoltage crowbar of -5 any described one kind according to claim 1, which is characterized in that the positive temperature
Degree coefficient resistance piece (4) can replace with the resistance of linear feature.
10. a kind of novel lightning protection over-pressure safety device, which is characterized in that using one kind as described in claim 1-9 is any
Novel lightning protection overvoltage crowbar.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2018213446917 | 2018-08-20 | ||
| CN201821344691 | 2018-08-20 |
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| CN209072063U true CN209072063U (en) | 2019-07-05 |
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| CN201821459904.0U Active CN209072063U (en) | 2018-08-20 | 2018-09-06 | A kind of novel lightning protection overvoltage crowbar and protective device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109066639A (en) * | 2018-08-20 | 2018-12-21 | 成都铁达电子股份有限公司 | A kind of novel lightning protection overvoltage crowbar and protective device |
| CN110336264A (en) * | 2019-08-22 | 2019-10-15 | 成都铁达电子股份有限公司 | A kind of pressure limiting circuit |
-
2018
- 2018-09-06 CN CN201821459904.0U patent/CN209072063U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109066639A (en) * | 2018-08-20 | 2018-12-21 | 成都铁达电子股份有限公司 | A kind of novel lightning protection overvoltage crowbar and protective device |
| CN110336264A (en) * | 2019-08-22 | 2019-10-15 | 成都铁达电子股份有限公司 | A kind of pressure limiting circuit |
| CN110336264B (en) * | 2019-08-22 | 2024-01-26 | 成都铁达电子股份有限公司 | Voltage limiting circuit |
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