CN208738824U - The overvoltage crowbar of welding machine and its power input - Google Patents
The overvoltage crowbar of welding machine and its power input Download PDFInfo
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- CN208738824U CN208738824U CN201821141168.4U CN201821141168U CN208738824U CN 208738824 U CN208738824 U CN 208738824U CN 201821141168 U CN201821141168 U CN 201821141168U CN 208738824 U CN208738824 U CN 208738824U
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Abstract
The utility model provides the overvoltage crowbar of a kind of welding machine and its power input; wherein overvoltage crowbar includes over-voltage detection circuit, the first driving circuit and protective switch; over-voltage detection circuit includes voltage sample circuit, reference data circuit and first voltage comparison circuit; voltage sample circuit, reference data circuit in first voltage comparison circuit accordingly compared with input terminal be electrically connected; the output end of first voltage comparison circuit is electrically connected with the input terminal of the first driving circuit, and the output end of the first driving circuit is electrically connected with the control terminal of protective switch.The voltage value of the power supply of the utility model real-time detection welding machine whether over-voltage, and the circuit that powers to welding machine of power supply is connected in non-over-voltage, and the circuit is cut off in over-voltage, it is ensured that welding machine will not be damaged because of over-voltage.
Description
Technical field
The utility model relates to welding machine power supply protection technical field, in particular to the mistake of a kind of welding machine and its power input
Voltage protection circuit.
Background technique
In view of polyethylene pipe be in current Municipal Industry gas conveyance conduit, water supply and sewerage pipeline use it is main
Conduit types, have occupied 90% or more market in European gas industry, have also obtained significantly increasing in recent years in China
Long, welding machine is increasingly used for as polyethylene pipe pipeline connecting device, and the power supply welded is generally 220V.But
In practical building site in use, the 220V electricity network in building site is second-rate, voltage value can exceed that 220V, in particular, working as work
When ground does not have 220V alternating current, it is often used generator and powers to welding machine, since there are the factors of instability, institutes for electrical power generators itself
With the 220V power supply and unstable of generator output, output voltage values meet or exceed 380V sometimes, if this voltage is for welding
Machine power supply, welding machine will be damaged or even be scrapped because of over-voltage.
Utility model content
The technical problems to be solved in the utility model be in order to overcome in the prior art welding machine because power supply over-voltage be easy
The defect for damaging or even scrapping provides the overvoltage crowbar of a kind of welding machine and its power input.
The utility model is to solve above-mentioned technical problem by following technical proposals:
The utility model provides a kind of overvoltage crowbar for welding machine electric power input terminal, its main feature is that, the over-voltage
Protecting circuit includes over-voltage detection circuit, the first driving circuit and protective switch, and the over-voltage detection circuit includes voltage sampling
Circuit, reference data circuit and first voltage comparison circuit, the voltage sample circuit, the reference data circuit and described the
Compare input terminal electrical connection, the output end of the first voltage comparison circuit and described first in one voltage comparator circuit accordingly
The input terminal of driving circuit is electrically connected, and the output end of first driving circuit is electrically connected with the control terminal of the protective switch；
The voltage sample circuit is used to export sampling voltage after carrying out direct current sampling to the power supply；
The reference data circuit is used to export the first reference voltage after carrying out pressure stabilizing to the power supply；
The first voltage comparison circuit is used to for the sampling voltage being compared with first reference voltage, and
The first driving voltage is exported to first driving circuit when sampling voltage is greater than first reference voltage, is taken described
The second driving voltage is exported to first driving circuit when sample voltage is not more than first reference voltage；
First driving circuit is used to export first switch signal according to first driving voltage, and according to described
Second driving voltage exports second switch signal；
The protective switch be used to disconnect when receiving the first switch signal power input of the welding machine with
Connection between power supply, and power input and the institute of the welding machine is connected when receiving the second switch signal
The connection between power supply is stated, the power supply is used to provide working power to the welding machine.
Preferably, the over-voltage detection circuit further includes second voltage comparison circuit；
The reference data circuit is also used to export the second reference voltage to after the power supply pressure stabilizing；
The second voltage comparison circuit exports the after being used for the sampling voltage compared with second reference voltage
One comparison voltage, first comparison voltage are used as the second comparison voltage after being superimposed with the sampling voltage；
The first voltage comparison circuit is used for by second comparison voltage compared with first reference voltage, and
Second comparison voltage exports first driving voltage when being greater than first reference voltage, in second comparison voltage
Second driving voltage is exported when no more than first reference voltage；
When the sampling voltage is greater than second reference voltage, the second voltage comparison circuit output described first
Comparison voltage is so that second comparison voltage is greater than first reference voltage, and in the sampling voltage no more than described the
When two reference voltages, the second voltage comparison circuit exports first comparison voltage so that second comparison voltage is less than
First reference voltage.
Preferably, the first voltage comparison circuit includes first diode and first voltage comparator, second electricity
Pressing comparison circuit includes the second diode and second voltage comparator；
The anode of the first diode is for inputting the sampling voltage, the cathode of the first diode and described the
It is connect after the cathode connection of two diodes with the negative input end of the first voltage comparator, the first voltage comparator is just
Input terminal is for inputting first reference voltage, the output end of the first voltage comparator and first driving circuit
Input terminal connection；
The positive input terminal of the second voltage comparator is used to input the sampling voltage, the second voltage comparator
Negative input end is for inputting second reference voltage, the output end of the second voltage comparator and second diode
Anode connection.
Preferably, the second voltage comparison circuit further includes third diode and the 4th diode, the three or two pole
The anode of pipe is for inputting the sampling voltage, the anode of the 4th diode and the output end of the second voltage comparator
Connection, the cathode of the third diode connect with the cathode of the 4th diode after with the second voltage comparator just
Input terminal connection.
Preferably, the voltage sample circuit includes step-down transformer, rectifier bridge, first resistor and second resistance, it is described
Reference data circuit includes voltage regulator circuit, 3rd resistor, the 4th resistance, the 5th resistance and the 6th resistance；
One end of the primary coil of the step-down transformer is connect with the first bus of the power supply, and the decompression becomes
The other end of the primary coil of depressor is connect with the second bus of the power supply, the secondary coil of the step-down transformer with
The input terminal of the rectifier bridge connects, the output plus terminal of the rectifier bridge respectively with one end of the first resistor, the pressure stabilizing
The input terminal of circuit connects, and the other end of the first resistor exports the sampling electricity after connecting with one end of the second resistance
Pressure, after the output negative terminal of the rectifier bridge is connect with the reference of the other end of the second resistance, the voltage regulator circuit respectively
As power ground；
The output end of the voltage regulator circuit is connect with one end of one end of the 3rd resistor, the 5th resistance, described
The other end of 3rd resistor exports first reference voltage after connecting with one end of the 4th resistance, the 5th resistance
The other end exports second reference voltage, the other end of the 4th resistance, institute after connecting with one end of the 6th resistance
The other end for stating the 6th resistance connects the power ground.
Preferably, the reference data circuit further includes the 7th resistance, the 8th resistance, the 9th resistance and the tenth resistance；
The cathode of the first diode is also connect with one end of one end of the 7th resistance, the 8th resistance, institute
The other end for stating the 7th resistance is connect with the output end of the voltage regulator circuit, and the other end of the 8th resistance connects the power supply
Ground；
The cathode of the third diode is also connect with one end of one end of the 9th resistance, the tenth resistance, institute
The other end for stating the 9th resistance is connect with the output end of the voltage regulator circuit, and the other end of the tenth resistance connects the power supply
Ground.
Preferably, the protective switch includes relay, first driving circuit includes first switch transistor and
11 resistance, one end of the eleventh resistor are connect with the output end of the first voltage comparator, the eleventh resistor
The other end connect with the base stage of the first switch transistor, the emitter of the first switch transistor connects the power supply
The collector on ground, the first switch transistor is connect with one end of the control signal of the relay, the relay
The other end of control signal is connect with the output plus terminal of the rectifier bridge, and the power input of the welding machine passes through the relay
The normally opened contact of device is connect with the power supply.
Preferably, the overvoltage crowbar for welding machine electric power input terminal further includes the second driving circuit and alarm electricity
Road, the input terminal of second driving circuit are connect with the output end of the second voltage comparator, second driving circuit
Output end connect with the warning circuit so that the warning circuit the sampling voltage be greater than second reference voltage
When sound an alarm.
Preferably, second driving circuit includes twelfth resistor and second switch transistor, the warning circuit packet
Buzzer is included, one end of the twelfth resistor is connect with the output end of the second voltage comparator, the twelfth resistor
The other end connect with the base stage of the second switch transistor, the emitter of the second switch transistor connects the power supply
Ground, the positive input terminal of the buzzer are connect with the output end of the voltage regulator circuit, the negative input end of the buzzer with it is described
The collector pole of second switch transistor connects.
The utility model also provides a kind of welding machine, its main feature is that, including being used for welding machine electric power described in any one of aforementioned
The overvoltage crowbar of input terminal.
The positive effect of the utility model is: the utility model passes through over-voltage detection circuit real-time detection welding machine
The voltage value of power supply whether over-voltage, and to control protective switch in time in an off state for driving circuit in over-voltage, in turn
The access that cutting power supply is powered to welding machine, and control circuit control protective switch is in the conductive state in non-over-voltage, into
And the access that power supply is powered to welding machine is connected, so the utility model in time, reliably can allow power supply to mention to welding machine
For reliable working power, it is ensured that welding machine will not be damaged because of over-voltage.
Detailed description of the invention
Fig. 1 is the composition signal of the overvoltage crowbar for welding machine electric power input terminal of the embodiments of the present invention 1
Figure.
Fig. 2 is the circuit diagram of the overvoltage crowbar for welding machine electric power input terminal of the embodiments of the present invention 2.
Specific embodiment
The utility model is further illustrated below by the mode of embodiment, but is not therefore limited in the utility model
Among the embodiment described range.
Embodiment 1
As shown in Figure 1, the overvoltage crowbar for welding machine electric power input terminal that the present embodiment is related to, overvoltage crowbar
1 includes over-voltage detection circuit 11, the first driving circuit 12 and protective switch 13, and over-voltage detection circuit 11 includes voltage sample circuit
111, reference data circuit 112 and first voltage comparison circuit 113.Wherein, voltage sample circuit 111, reference data circuit 112
With in first voltage comparison circuit 113 accordingly compared with input terminal be electrically connected, the output end of first voltage comparison circuit 113 and the
The input terminal of one drive circuit 12 is electrically connected, and the output end of the first driving circuit 12 is electrically connected with the control terminal of protective switch 13；
Voltage sample circuit 111 is used to export sampling voltage Vsamp after carrying out direct current sampling to power supply 2；Reference data circuit 112
For exporting the first reference voltage Vref1 after carrying out pressure stabilizing to power supply 2；First voltage comparison circuit 113 will be for that will sample
Voltage Vsamp is compared with the first reference voltage Vref1, and when sampling voltage Vsamp is greater than the first reference voltage Vref1
The first driving voltage is exported to the first driving circuit 12, is not more than the first reference voltage Vref1 Shi Xiang in sampling voltage Vsamp
One drive circuit 12 exports the second driving voltage；First driving circuit 12 is used to be opened according to first driving voltage output first
OFF signal, and second switch signal is exported according to second driving voltage；Protective switch 13 is used to receive described the
The connection between the power input and power supply 2 of welding machine 3 is disconnected when one switching signal, and is opened receiving described second
The connection between the power input and power supply 2 of welding machine 3 is connected when OFF signal, power supply 2 is used to provide work to welding machine 3
Make power supply.It will be understood by those of skill in the art that in the present embodiment, first driving voltage and second driving voltage
Voltage form should be set according to the needs of the first driving circuit 12；Equally, the first switch signal and described second is opened
The signal form of OFF signal, should by the protective switch to control signal demand and set.
In specific implementation, single only switch such as single-pole single-throw switch (SPST) (the normally opened single-pole single-throw switch (SPST) in such as figure) can be used and make
For protective switch 13, at this moment a wherein inlet highway (Lin1 in such as figure) for the power input of welding machine 3 is opened by protection
13 are closed to connect with a bus (L1 in such as figure) for power supply 2, and another inlet highway of the power input of welding machine 3 is (such as
Lin2 in figure) it is directly connect with another bus of power supply 2 (L2 in such as figure) by the conducting wire in overvoltage crowbar 1
Forming circuit.
In this way, when in use, the power input of welding machine 3 can be connect by overvoltage crowbar 1 with power supply 2, when
When over-voltage occurs in power supply 2, protective switch 13 will be not turned on, to cut off power input of the power supply 2 to welding machine 3
The circuit of power supply is provided.
In the present embodiment, also by being further added by voltage comparator circuit all the way in over-voltage detection circuit 11, further to mention
Exceed the job stability and reliability of voltage protection circuit 1.
Specifically, over-voltage detection circuit 11 further includes second voltage comparison circuit 114, and reference data circuit 112 is also used to
To the second reference voltage Vref2 is exported after 2 pressure stabilizing of power supply, second voltage comparison circuit 114 is used for sampling voltage Vsamp
The first comparison voltage V1, such first comparison voltage V1 and sampling voltage Vsamp is exported after compared with the second reference voltage Vref2
The second comparison voltage V2 is used as after superposition, at this moment first voltage comparison circuit 113 is just used for the second comparison voltage V2 and first
Reference voltage Vref1 compares, and the first driving electricity is exported when the second comparison voltage V2 is greater than the first reference voltage Vref1
Pressure exports second driving voltage when the second comparison voltage V2 is not more than the first reference voltage Vref1；In addition, sampling
When voltage Vsamp is greater than the second reference voltage Vref2, second voltage comparison circuit 114 exports the first comparison voltage V1 so that the
Two comparison voltage V2 are greater than the first reference voltage Vref1, ensure that first voltage comparison circuit 113 can steadily, reliably
First driving voltage is exported, such first driving circuit 12 can steadily export the first switch signal, and protection is opened
The power input and power supply electricity of welding machine 3 can steadily, reliably be disconnected under the control of the first switch signal by closing 13
Connection between source 2, and when sampling voltage Vsamp is not more than the second reference voltage V2, second voltage comparison circuit 114 exports
First comparison voltage V1 is so that the second comparison voltage V2 ensure that first voltage comparison circuit less than the first reference voltage Vref1
113 can steadily, reliably export second driving voltage, and such first driving circuit 12 can steadily export described
Second switch signal, protective switch 13 can under the control of the second switch signal steadily, welding machine 3 is reliably connected
Connection between power input and power supply 2.
In this implementation, the core circuit of first voltage comparison circuit 113 and second voltage comparison circuit 114 is all made of voltage
Comparator circuit form.
Specifically, first voltage comparison circuit 113 includes first diode D1 and first voltage comparator U1, second voltage
Comparison circuit 114 includes the second diode D2 and second voltage comparator U2.At this moment, the anode of first diode D1 is for inputting
Sampling voltage Vsamp, the cathode of first diode D1 connect with the cathode of the second diode D2 after with first voltage comparator U1
Negative input end connection, the positive input terminal of first voltage comparator U1 is for inputting the first reference voltage Vref1, first voltage ratio
Output end compared with device U1 is connect with the input terminal of the first driving circuit 12；The positive input terminal of second voltage comparator U2 is for inputting
The negative input end of sampling voltage Vsamp, second voltage comparator U2 are for inputting the second reference voltage Vref2, second voltage ratio
Output end compared with device U2 is connect with the anode of the second diode D2, and the first of the output end output of such second voltage comparator U2
Comparison voltage V1 the second diode D2 isolation, sampling voltage Vsamp is isolated through first diode D1, and the is formed after then superimposed
Two comparison voltage V2, in this way, first voltage comparator U1 be just used for the first reference voltage Vref1 and the second comparison voltage V2 into
Row compares.
In the present embodiment, in order to realize more reliable overvoltage protection when over-voltage occurs in power supply 2, also by by second
The output result of voltage comparator U2 feeds back to its positive input terminal, in this way when sampling voltage Vsamp is greater than the second reference voltage
When Vref2, second voltage comparator U2 will export the first comparison voltage V1 of high potential, the first comparison voltage V1 of the high potential
After feeding back to the positive input terminal of second voltage comparator U2, i.e. the first comparison voltage V1 and sampling voltage Vsamp of the high potential
The positive input terminal for entering second voltage comparator U2 after superposition, since sampling voltage Vsamp has been greater than the second reference voltage at this time
Vref2, at this moment second voltage comparator U2 will more stably export the first comparison voltage V1 of the high potential, the in this way high potential
The first comparison voltage V1 be superimposed again with sampling voltage Vsamp after enter the negative input end of first voltage comparator U1 so that
Be superimposed obtained the second comparison voltage V2 by it is more stable, be more reliably greater than the first reference voltage Vref1, thus first voltage ratio
Compared with device U1 by it is more stable, more reliably export first driving voltage, finally realize more stable, more reliable overvoltage protection.
Specifically, second voltage comparison circuit 114 further includes third diode D3 and the 4th diode D4, the anode of third diode D3
For inputting sampling voltage Vsamp, the anode of the 4th diode D4 is connect with the output end of second voltage comparator U2, and the three or two
The cathode of pole pipe D3 is connect after connecting with the cathode of the 4th diode D4 with the positive input terminal of second voltage comparator U2.
Embodiment 2
As shown in Fig. 2, the overvoltage crowbar for welding machine electric power input terminal that the present embodiment is related to, is in embodiment 1
On the basis of, it is compared after carrying out direct current sampling and sampling for power supply 2 of the realization to alternating current, voltage sample circuit
111 are depressured and are rectified to power supply 2 first, then obtain out sampling voltage Vsamp, and reference by electric resistance partial pressure
Reference circuit 112 exports the first reference voltage Vref1 and the second benchmark electricity by reference voltage generating circuit again after pressure stabilizing
Vref2 is pressed, reference voltage generating circuit uses resistor voltage divider circuit form, the first reference voltage Vref1 not only exported here
It is able to satisfy circuit performance requirement with the second reference voltage Vref2, also simplify circuit design and reduces circuit cost, Er Qie
One reference voltage Vref1 and the second reference voltage Vref2 can carry out flexible setting by adjusting the resistance value of divider resistance.
Specifically, voltage sample circuit 111 includes step-down transformer T1, rectifier bridge BR1, first resistor R1 and second resistance
R2, reference data circuit 112 include voltage regulator circuit 1121,3rd resistor R3, the 4th resistance R4, the 5th resistance R5 and the 6th resistance
R6, one end of the primary coil of step-down transformer T1 are connect with the first bus L1 of power supply 2, the primary of step-down transformer T1
The other end of coil is connect with the second bus L2 of power supply 2, and the secondary coil of step-down transformer T1 is defeated with rectifier bridge BR1's
Entering end connection, the output plus terminal of rectifier bridge BR1 is connect with the input terminal of one end of first resistor R1, voltage regulator circuit 1121 respectively,
The other end of first resistor R1 exports sampling voltage Vsamp after connecting with one end of second resistance R2, the output of rectifier bridge BR1 is negative
End is used as power ground after connecting respectively with the reference of the other end of second resistance R2, voltage regulator circuit 1121；Voltage regulator circuit 1121
Output end connect with one end of one end of 3rd resistor R3, the 5th resistance R5, the other end of 3rd resistor R3 and the 4th resistance
The first reference voltage Vref1 is exported after one end connection of R4, the other end of the 5th resistance R5 is connect with one end of the 6th resistance R6
After export the other end of the second reference voltage Vref2, the 4th resistance R4, the other end of the 6th resistance R6 connects the power ground.
When it is implemented, the preferable linear voltage regulator U3 of voltage regulator circuit 1121, and the preferred LM7810 of linear voltage regulator U3, this
When linear voltage regulator U3 input terminal Vin be connected to the positive output end of rectifier bridge BR1, the reference end GND of linear voltage regulator U3 connects
It is connected to the power ground, the i.e. negative output terminal of rectifier bridge BR1, the output end vo of linear voltage regulator U3 exports 10V voltage, the 10V
Voltage is for the power supply of first voltage comparator U1 and second voltage comparator U2 and for 3rd resistor R3 and the 4th resistance
R4 partial pressure the first reference voltage Vref1 of output, for the 5th resistance R5 and the 6th resistance R6 partial pressure the second reference voltage of output
Vref2.In addition, the input terminal Vin of linear voltage regulator U3 is connected to, capacitor C1 carries out input filter, output end vo is connected to capacitor
C2 carries out output filtering, to improve voltage regulation performance；The both ends resistance R4 are also parallel with capacitor C3 further to the first base of output
Quasi- voltage Vref1 is filtered.
In addition, being inputted again after the general series resistor of positive input terminal (the resistance R13 in such as figure) of first voltage comparator U1
First reference voltage Vref1, also series resistor (the resistance R14 in such as figure) inputs the negative input end of first voltage comparator U1 again
Second comparison voltage V2, and resistance R13 and resistance R14 selects the identical resistance of resistance value.Equally, second voltage comparator U2
Positive input terminal series resistor (the resistance R15 in such as figure), negative input end series resistor (the resistance R16 in such as figure), and resistance R15
Resistance identical with resistance R16 selection resistance value.
And preferably dual comparator integrated circuit, such first voltage comparator U1 and second voltage comparator U2 collect
At in the dual comparator integrated circuit, so that comparator periphery circuit design is simplified, and the dual comparator integrated circuit
Power supply is provided by voltage regulator circuit 1121, i.e. power positive end (the first voltage comparator in such as figure of the dual comparator integrated circuit
The V+ of U1) it is connected to the output end of voltage regulator circuit 1121, power supply negative terminal (the first electricity in such as figure of the dual comparator integrated circuit
Press the V- of comparator U1) it is connected to the power ground.
In the present embodiment, before carrying out voltage relatively, also by reference to reference circuit 112 to being input in comparison circuit
Sampling voltage Vsamp carries out direct current biasing and also improves overvoltage protection to improve the flexibility of parameter setting in overvoltage protection
Stability and reliability.
Specifically, reference data circuit 112 further includes the 7th resistance R7, the 8th resistance R8, the electricity of the 9th resistance R9 and the tenth
Hinder R10.Wherein, the cathode of first diode D1 is also connect with one end of one end of the 7th resistance R7, the 8th resistance R8, the 7th electricity
The other end of resistance R7 is connect with the output end (i.e. the output end vo of linear voltage regulator U3) of voltage regulator circuit 1121, the 8th resistance R8's
The other end connects the power ground；The cathode of third diode also connects with one end of one end of the 9th resistance R9, the tenth resistance R10
It connecing, the other end of the 9th resistance R9 is connect with the output end (i.e. the output end vo of linear voltage regulator U3) of voltage regulator circuit 1121, the
The other end of ten resistance R10 connects the power ground.
In the present embodiment, using relay as protective switch 13, correspondingly, driven using transistor as driving circuit
Motor type relay work, not only simplifies circuit design, also reduces circuit cost.Specifically, protective switch 13 includes relay K1,
First driving circuit 12 includes first switch transistor Q1 and eleventh resistor R11, one end of eleventh resistor R11 and the first electricity
The output end connection of comparator U1 is pressed, the other end of eleventh resistor R11 is connect with the base stage of first switch transistor Q1, and first
The emitter of switching transistor Q1 connects the power ground, and the control of the collector and relay K1 of first switch transistor Q1 is defeated
Enter one end connection at end, the other end of the control signal of relay K1 is connect with the output plus terminal of rectifier bridge BR1, such welding machine
3 power input is connect by the normally opened contact of relay K1 with power supply 2.Here, the preferred solid relay of relay K1
Device, and an inlet highway (Lin1 in such as figure) for the power input of welding machine 3 passes through solid-state relay and the one of power supply 2
Bus (L1 in such as figure) connection, and another inlet highway (Lin2 in such as figure) of the power input of welding machine 3 passes through over-voltage
Protection circuit 1 directly connects and composes circuit with another bus of power supply 2 (L2 in such as figure).Certainly, the control of relay K1
The both ends parallel diode (the diode D5 in such as figure) of input terminal processed come absorb relay K1 generation spike.
In the present embodiment, also sounded an alarm in time using warning circuit when there is over-voltage, in order to which Field Force is timely
Understand overvoltage protection situation.Specifically, overvoltage crowbar 1 further includes the second driving circuit 14 and warning circuit 15, and second drives
The input terminal of dynamic circuit 14 is connect with the output end of second voltage comparator U2, the output end and alarm electricity of the second driving circuit 14
Road 15 connects so that warning circuit 15 is sounded an alarm when sampling voltage Vsamp is greater than the second reference voltage Vref2.
When it is implemented, circuit form of second driving circuit 14 using the first driving circuit 12, warning circuit 15 use
The buzzer of small size, i.e. the second driving circuit 14 include twelfth resistor R12 and second switch transistor Q2, warning circuit 15
Including buzzer BZ, one end of twelfth resistor R12 is connect with the output end of second voltage comparator U2, twelfth resistor R12
The other end connect with the base stage of second switch transistor Q2, the emitter of second switch transistor Q2 connects the power ground,
The positive input terminal of buzzer BZ is connect with the output end of voltage regulator circuit 1121, the negative input end and second switch crystal of buzzer BZ
The collector pole of pipe Q2 connects.In addition, diode D7 absorbs buzzer BZ and produces using the power supply of diode D6 isolation buzzer BZ
Raw peak voltage, specific connection repeat no more.
When it is implemented, further include fuse FU in overvoltage crowbar 1, such 2 (power supply electricity in such as figure of power supply
The one bus L1 in source 2) pass through the power input (welding machine in such as figure with voltage sample circuit 11, welding machine 3 again after fuse FU
One bus Lin1 of 3 power input) connection.
For convenient for it will be understood by those skilled in the art that and implement the utility model, provide the main of each device in circuit here
Parameter.Wherein, turn ratio (the ratio between the number of turns and the number of turns of secondary coil of primary coil) preferred 19:1 of step-down transformer T1, it is whole
Stream bridge BR1 can be selected diode bridge heap and can also be made of four rectifier diodes, the preferred 10k Ω of the resistance value of resistance R1, resistance
The preferred 5.1k Ω of the resistance value of R2；Linear voltage regulator U3 preferred LM7810, capacitor the C1 preferably polar capacitor of 1000 μ F/50V,
The capacitor C2 preferably polar capacitor of 47 μ F/50V, the capacitor C3 preferably polar capacitor of 100 μ F/50V；It is serially connected with voltage
The preferred 10k Ω of resistance value of the resistance (resistance R13~R16 in figure) of comparator input terminal；By 3rd resistor R3 and the 4th resistance
The first reference voltage Vref1 that R4 partial pressure generates and the second reference voltage generated by the 5th resistance R5 and the 6th resistance R6 partial pressure
Vref2 uses identical value, and the preferred 10k of resistance value of 3rd resistor R3, the 4th resistance R4, the 5th resistance R5 and the 6th resistance R6
Ω；The preferred 10k Ω of resistance value of 7th resistance R7, the 9th resistance R9, eleventh resistor R11, twelfth resistor R12, the 8th electricity
Resistance R8, the tenth resistance R10 resistance value preferred 6.8k Ω, first voltage comparator U1 and second voltage comparator U2 be integrated in it is double
In comparator integrated circuit；The preferred small high-power relay of relay K1, specification JQX-102F；The specified electricity of fuse FU
Stream is 15A.
In this present embodiment, selected device volume is small, integrated level is high for mirror, so overvoltage crowbar 1 is small in size, again
Amount is light, is not necessarily to nuisance operation, and very convenient site operation personnel carries and uses.
Embodiment 3
The present embodiment is related to a kind of welding machine, and the welding machine includes described in previous embodiment 1 or embodiment 2 for welding machine
The overvoltage crowbar of power input, wherein overvoltage crowbar 1 is embeddable or is integrated in the welding machine, thus described
Welding machine can directly be connect with external power supply.
Although the foregoing describe specific embodiment of the present utility model, it will be appreciated by those of skill in the art that
This is merely illustrative of, and the protection scope of the utility model is defined by the appended claims.Those skilled in the art
Under the premise of without departing substantially from the principles of the present invention and essence, many changes and modifications may be made,
But these change and modification each fall within the protection scope of the utility model.
Claims (10)
1. a kind of overvoltage crowbar of welding machine electric power input terminal, which is characterized in that the over-voltage of the welding machine electric power input terminal is protected
Protection circuit includes over-voltage detection circuit, the first driving circuit and protective switch, and the over-voltage detection circuit includes voltage sampling electricity
Road, reference data circuit and first voltage comparison circuit, the voltage sample circuit, the reference data circuit and described first
Compare input terminal electrical connection in voltage comparator circuit accordingly, the output end of the first voltage comparison circuit and described first drive
The input terminal electrical connection of dynamic circuit, the output end of first driving circuit are electrically connected with the control terminal of the protective switch；
The voltage sample circuit is used to export sampling voltage after carrying out direct current sampling to power supply；
The reference data circuit is used to export the first reference voltage after carrying out pressure stabilizing to the power supply；
The first voltage comparison circuit is used to for the sampling voltage being compared with first reference voltage, and described
The first driving voltage is exported to first driving circuit when sampling voltage is greater than first reference voltage, in the sampling electricity
The second driving voltage is exported to first driving circuit when pressure is no more than first reference voltage；
First driving circuit is used to export first switch signal according to first driving voltage, and according to described second
Driving voltage exports second switch signal；
The protective switch is used to disconnect power input and the power supply of the welding machine when receiving the first switch signal
Connection between power supply, and be connected when receiving the second switch signal welding machine power input and the confession
Connection between power supply, the power supply are used to provide working power to the welding machine.
2. the overvoltage crowbar of welding machine electric power input terminal as described in claim 1, which is characterized in that the over-voltage detection electricity
Road further includes second voltage comparison circuit；
The reference data circuit is also used to export the second reference voltage to after the power supply pressure stabilizing；
The second voltage comparison circuit is used to exporting the sampling voltage into the first ratio afterwards compared with second reference voltage
Compared with voltage, first comparison voltage is used as the second comparison voltage after being superimposed with the sampling voltage；
The first voltage comparison circuit is used for by second comparison voltage compared with first reference voltage, and described
Second comparison voltage exports first driving voltage when being greater than first reference voltage, little in second comparison voltage
Second driving voltage is exported when first reference voltage；
When the sampling voltage is greater than second reference voltage, the second voltage comparison circuit output described first is compared
Voltage is so that second comparison voltage is greater than first reference voltage, and is not more than second base in the sampling voltage
When quasi- voltage, the second voltage comparison circuit exports first comparison voltage so that second comparison voltage is less than described
First reference voltage.
3. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 2, which is characterized in that the first voltage ratio
It include first diode and first voltage comparator compared with circuit, the second voltage comparison circuit includes the second diode and second
Voltage comparator；
The anode of the first diode is for inputting the sampling voltage, the cathode of the first diode and the described 2nd 2
It is connect after the cathode connection of pole pipe with the negative input end of the first voltage comparator, the positive input of the first voltage comparator
End is for inputting first reference voltage, the input of the output end of the first voltage comparator and first driving circuit
End connection；
For the positive input terminal of the second voltage comparator for inputting the sampling voltage, bearing for the second voltage comparator is defeated
Enter end for inputting second reference voltage, the anode of the output end of the second voltage comparator and second diode
Connection.
4. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 3, which is characterized in that the second voltage ratio
It further include third diode and the 4th diode compared with circuit, the anode of the third diode is used to input the sampling voltage,
The anode of 4th diode is connect with the output end of the second voltage comparator, the cathode of the third diode and institute
It is connect after stating the cathode connection of the 4th diode with the positive input terminal of the second voltage comparator.
5. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 4, which is characterized in that the voltage sampling electricity
Road includes step-down transformer, rectifier bridge, first resistor and second resistance, and the reference data circuit includes voltage regulator circuit, third
Resistance, the 4th resistance, the 5th resistance and the 6th resistance；
One end of the primary coil of the step-down transformer is connect with the first bus of the power supply, the step-down transformer
The other end of primary coil connect with the second bus of the power supply, the secondary coil of the step-down transformer with it is described
The input terminal of rectifier bridge connects, the output plus terminal of the rectifier bridge respectively with one end of the first resistor, the voltage regulator circuit
Input terminal connection, the other end of the first resistor exports the sampling voltage after connecting with one end of the second resistance,
Conduct after the output negative terminal of the rectifier bridge is connect with the reference of the other end of the second resistance, the voltage regulator circuit respectively
Power ground；
The output end of the voltage regulator circuit is connect with one end of one end of the 3rd resistor, the 5th resistance, the third
The other end of resistance exports first reference voltage after connecting with one end of the 4th resistance, the 5th resistance it is another
End exports second reference voltage after connecting with one end of the 6th resistance, the other end of the 4th resistance, described the
The other end of six resistance connects the power ground.
6. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 5, which is characterized in that the reference data electricity
Road further includes the 7th resistance, the 8th resistance, the 9th resistance and the tenth resistance；
The cathode of the first diode is also connect with one end of one end of the 7th resistance, the 8th resistance, and described
The other end of seven resistance is connect with the output end of the voltage regulator circuit, and the other end of the 8th resistance connects the power ground；
The cathode of the third diode is also connect with one end of one end of the 9th resistance, the tenth resistance, and described
The other end of nine resistance is connect with the output end of the voltage regulator circuit, and the other end of the tenth resistance connects the power ground.
7. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 5, which is characterized in that the protective switch packet
Relay is included, first driving circuit includes first switch transistor and eleventh resistor, one end of the eleventh resistor
It is connect with the output end of the first voltage comparator, the other end of the eleventh resistor and the first switch transistor
The emitter of base stage connection, the first switch transistor connects the power ground, the collector of the first switch transistor
It is connect with one end of the control signal of the relay, the other end of the control signal of the relay and the rectifier bridge
Output plus terminal connection, the power input of the welding machine connected by the normally opened contact of the relay and the power supply
It connects.
8. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 5, which is characterized in that the welding machine electric power is defeated
The overvoltage crowbar for entering end further includes the second driving circuit and warning circuit, the input terminal of second driving circuit with it is described
The output end of second voltage comparator connects, and the output end of second driving circuit is connect so that described with the warning circuit
Warning circuit is sounded an alarm when the sampling voltage is greater than second reference voltage.
9. the overvoltage crowbar of welding machine electric power input terminal as claimed in claim 8, which is characterized in that the second driving electricity
Road includes twelfth resistor and second switch transistor, and the warning circuit includes buzzer, one end of the twelfth resistor
It is connect with the output end of the second voltage comparator, the other end of the twelfth resistor and the second switch transistor
Base stage connection, the emitter of the second switch transistor connect the power ground, the positive input terminal of the buzzer with it is described
The output end of voltage regulator circuit connects, and the negative input end of the buzzer is connect with the collector of the second switch transistor.
10. a kind of welding machine, which is characterized in that the mistake including welding machine electric power input terminal as claimed in any one of claims 1-9 wherein
Voltage protection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821141168.4U CN208738824U (en) | 2018-07-18 | 2018-07-18 | The overvoltage crowbar of welding machine and its power input |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821141168.4U CN208738824U (en) | 2018-07-18 | 2018-07-18 | The overvoltage crowbar of welding machine and its power input |
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| CN208738824U true CN208738824U (en) | 2019-04-12 |
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| Application Number | Title | Priority Date | Filing Date |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113161989A (en) * | 2021-04-27 | 2021-07-23 | 长城电源技术有限公司 | Digital power supply, fault detection circuit and method thereof, and computer readable storage medium |
| CN113225875A (en) * | 2021-04-20 | 2021-08-06 | 深圳市崧盛电子股份有限公司 | Drive power supply and output short-circuit protection circuit thereof |
| CN115207875A (en) * | 2022-08-10 | 2022-10-18 | 深圳市索源科技有限公司 | Time delay switch circuit with overvoltage protection and electronic equipment |
-
2018
- 2018-07-18 CN CN201821141168.4U patent/CN208738824U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113225875A (en) * | 2021-04-20 | 2021-08-06 | 深圳市崧盛电子股份有限公司 | Drive power supply and output short-circuit protection circuit thereof |
| CN113161989A (en) * | 2021-04-27 | 2021-07-23 | 长城电源技术有限公司 | Digital power supply, fault detection circuit and method thereof, and computer readable storage medium |
| CN115207875A (en) * | 2022-08-10 | 2022-10-18 | 深圳市索源科技有限公司 | Time delay switch circuit with overvoltage protection and electronic equipment |
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