CN107528289A - Electromagnetic heating system and its protection device - Google Patents
Electromagnetic heating system and its protection device Download PDFInfo
- Publication number
- CN107528289A CN107528289A CN201610455122.9A CN201610455122A CN107528289A CN 107528289 A CN107528289 A CN 107528289A CN 201610455122 A CN201610455122 A CN 201610455122A CN 107528289 A CN107528289 A CN 107528289A
- Authority
- CN
- China
- Prior art keywords
- resistance
- circuit
- switching tube
- signal
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/10—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current additionally responsive to some other abnormal electrical conditions
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/20—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage
- H02H3/22—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage of short duration, e.g. lightning
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/082—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit
Landscapes
- Inverter Devices (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a kind of electromagnetic heating system and its protection device, described device includes：Forward voltage surge detects circuit, and forward voltage surging signal is exported when the input voltage for detecting electromagnetic heating system is more than the first predeterminated voltage；Current surge detects circuit, the output current surging signal when the operating current for detecting switching tube is more than the first predetermined current；Switching tube over-voltage detection circuit, the output switch pipe overvoltage signal when the collector voltage for detecting switching tube is more than the second predeterminated voltage；Triggers circuit is according to forward voltage surging signal, current surge signal and switching tube overvoltage signal output trigger protection signal, to be turned off by drive circuit driving switch pipe.The device can not only avoid forward voltage surging signal and current surge signal from being influenceed to caused by system; and switching tube can be avoided to puncture because bearing too high back-pressure; also, the drive circuit of switching tube is directly acted on after protection signal triggering, so as to improve the protection speed of system.
Description
Technical field
The present invention relates to household electrical appliance technical field, more particularly to a kind of protection device of electromagnetic heating system and a kind of tool
There is its electromagnetic heating system.
Background technology
Generally, electromagnetic heating system such as electromagnetic oven at work, is highly prone to voltage surge in power network and work system and believed
Number and current surge signal interference, because the instantaneous interference signal amplitude of surge is big, destructive strong, thus easily damage system
In component, cause electromagnetic oven operational failure, there is very big potential safety hazard.
In correlation technique, electromagnetic oven is designed with surge protection mechanism, but positive unidirectional surge protection mechanism has one
The drawbacks of determining：When negative voltage surging signal comes temporarily, due to the original of capacitor charge and discharge be present prior to forward voltage surging signal
Cause so that the voltage surge signal of controller detection is pulled low, can if the time interval of two voltage surge signals is very short
It can not completely set up triggering surge to interrupt, cause Lou to protect, now energy is accumulated on switching tube completely, and switching tube has wink
Between over-voltage breakdown risk.
The content of the invention
It is contemplated that at least solves one of technical problem in correlation technique to a certain extent.Therefore, the present invention
One purpose is to propose a kind of protection device of electromagnetic heating system, can not only avoid forward voltage surging signal and electric current
Surging signal is influenceed to caused by system, and switching tube can be avoided to puncture because bearing too high back-pressure, also, protection signal
The drive circuit of switching tube is directly acted on after triggering, so as to improve the protection speed of system, and then improves the anti-of system
Interference performance and reliability.
It is another object of the present invention to propose a kind of electromagnetic heating system.
To achieve the above object, one aspect of the present invention embodiment proposes a kind of protection device of electromagnetic heating system, institute
State electromagnetic heating system include resonance circuit, to the resonance circuit provide energy current rectifying and wave filtering circuit, driving switch pipe open
Logical or shut-off drive circuit, the resonance circuit are made up of heating coil, resonant capacitance and the switching tube, the protection dress
Put including：Forward voltage surge detects circuit, and the forward voltage surge detection circuit is detecting the electromagnetic heating system
Input voltage export forward voltage surging signal when being more than the first predeterminated voltage；Current surge detects circuit, the electric current wave
Gush detection circuit output current surging signal when the operating current for detecting the switching tube is more than the first predetermined current；Switch
Pipe over-voltage detection circuit, the switching tube over-voltage detection circuit are connected with the colelctor electrode of the switching tube to detect described open
Output switch pipe overvoltage signal when the collector voltage of pass pipe is more than the second predeterminated voltage；Triggers circuit, the triggers circuit tool
There are the first signal input part, secondary signal input, the 3rd signal input part and trigger output end, first signal input part
It is connected with the output end of forward voltage surge detection circuit, the secondary signal input and current surge detection electricity
Road is connected, and the 3rd signal input part is connected with the switching tube over-voltage detection circuit, the trigger output end and the drive
Dynamic circuit is connected, and the triggers circuit is according to the forward voltage surging signal, the current surge signal and the switching tube
Over-pressed signal output trigger protection signal, to drive the switching tube to turn off by the drive circuit.
The protection device of electromagnetic heating system according to embodiments of the present invention, forward voltage surge detection circuit are detecting
The input voltage of electromagnetic heating system exports forward voltage surging signal, current surge detection circuit when being more than the first predeterminated voltage
The output current surging signal when the operating current for detecting switching tube is more than the first predetermined current, switching tube over-voltage detection circuit
The output switch pipe overvoltage signal when the collector voltage for detecting switching tube is more than the second predeterminated voltage, triggers circuit is according to just
To voltage surge signal, current surge signal and switching tube overvoltage signal output trigger protection signal, to be driven by drive circuit
Dynamic switching tube shut-off, so as to which forward voltage surging signal and current surge signal can not only be avoided to be influenceed to caused by system,
And switching tube can be avoided to puncture because bearing too high back-pressure, also, directly act on switching tube after protection signal triggering
Drive circuit, so as to improve the protection speed of system, and then improve the antijamming capability and reliability of system.
According to one embodiment of present invention, the input of the current surge detection circuit is connected to by first resistor
The emitter stage of the switching tube is to detect the operating current of the switching tube.
Further, the first resistor is constantan wire.
According to one embodiment of present invention, the current surge detection circuit includes：The second resistance of series connection and the 3rd
Resistance, one end of the second resistance are connected with one end of the first resistor, the other end of the second resistance and described the
One end of three resistance is connected, and the other end of the 3rd resistor is connected with default power supply, the other end of the second resistance and institute
Stating between one end of 3rd resistor has first node, and the first node is connected to the ground by the first electric capacity；First diode,
The anode of first diode is connected with the first node；First comparator, the negative input end of the first comparator with
The negative electrode of first diode is connected, and the positive input terminal of the first comparator is connected with the first reference voltage, and described first
The output end of comparator is connected with the secondary signal input of the triggers circuit.
According to one embodiment of present invention, the current rectifying and wave filtering circuit include rectifier bridge, Absorption Capacitance, choking-winding and
Storage capacitor, the first input end of the rectifier bridge and the second input correspondingly connect the both ends of electric main, described to absorb electricity
Appearance is connected in parallel between the first output end of the rectifier bridge and the second output end, one end of the choking-winding and the rectifier bridge
The first output end be connected, the other end of the choking-winding is connected with one end of the storage capacitor, and be connected to parallel connection
Resonant capacitance and heating coil, the other end of the storage capacitor are connected with the second output end of the rectifier bridge.
Further, the input of the forward voltage surge detection circuit is connected with the first output end of the rectifier bridge
To detect the input voltage of the electromagnetic heating system.
Further, the forward voltage surge detection circuit includes：4th to the 6th resistance of series connection, the 4th electricity
One end of resistance is connected with the first output end of the rectifier bridge, the other end of the 4th resistance and one end of the 5th resistance
It is connected, the other end of the 5th resistance is connected with one end of the 6th resistance, the other end ground connection of the 6th resistance, and
5th resistor coupled in parallel has the second electric capacity, and the 6th resistance and the 7th resistance connected and the 3rd electric capacity are in parallel, and described the
There is section point between one end of the other end of five resistance and the 6th resistance；Second diode, second diode
Anode be connected with the section point；Second comparator, the positive input terminal of second comparator and second diode
Negative electrode be connected, the negative input end of second comparator is connected with the second reference voltage, the output end of second comparator
It is connected with the first signal input part of the triggers circuit.
According to one embodiment of present invention, the switching tube over-voltage detection circuit includes：8th resistance of series connection and the
Nine resistance, one end of the 8th resistance are connected with the colelctor electrode of the switching tube, the other end of the 8th resistance with it is described
One end of 9th resistance is connected, the other end ground connection of the 9th resistance, and the other end and the described 9th of the 8th resistance
There is the 3rd node, the 9th resistor coupled in parallel has the 4th electric capacity between one end of resistance；3rd comparator, the described 3rd compares
The positive input terminal of device is connected with the 3rd node, and the negative input end of the 3rd comparator is connected with the 3rd reference voltage, institute
The output end of the 3rd comparator is stated with the 3rd signal input part of the triggers circuit to be connected.
According to one embodiment of present invention, the triggers circuit is three input nor gates.
Further, the three inputs nor gate includes：OR gate, the first input end of the OR gate and the forward voltage
Surge detection circuit is connected, and the second input of the OR gate is connected with current surge detection circuit；Nor gate, it is described or
The first input end of NOT gate is connected with the switching tube over-voltage detection circuit, the second input and the OR gate of the nor gate
Output end be connected；3rd diode, the negative electrode of the 3rd diode are connected with the output end of the nor gate, and the described 3rd
The anode of diode is connected with the drive circuit.
According to one embodiment of present invention, the drive circuit includes：First NPN triode, the poles of the first NPN tri-
The colelctor electrode of pipe is connected by the tenth resistance with default power supply, base stage and the triggers circuit of first NPN triode
Output end is connected, and the emitter stage of first NPN triode is connected with the base stage of the switching tube；First PNP triode, it is described
The emitter stage of first PNP triode is connected with the emitter stage of first NPN triode, the base stage of first PNP triode
It is connected with the base stage of first NPN triode, the colelctor electrode of first PNP triode and the emitter stage phase of the switching tube
It is grounded after even；Second NPN triode, the colelctor electrode of second NPN triode base stage with first NPN triode respectively
It is connected with one end of the 11st resistance, the 11st resistance other end is connected with the default power supply, the poles of the 2nd NPN tri-
The grounded emitter of pipe；The 12nd resistance and the 13rd resistance of series connection, one end and the 2nd NPN of the 12nd resistance
The base stage of triode is connected, and the other end of the 12nd resistance is connected with one end of the 13rd resistance, and the described 13rd
The other end of resistance is connected with the default power supply, the other end of the 12nd resistance and one end of the 13rd resistance it
Between there is fourth node, the fourth node is connected with controller.
In addition, embodiments of the invention also proposed a kind of electromagnetic heating system, it includes above-mentioned electromagnetic heating system
Protection device.
The electromagnetic heating system of the embodiment of the present invention, can not only by the protection device of above-mentioned electromagnetic heating system
Avoid forward voltage surging signal and current surge signal from being influenceed to caused by system, and switching tube can be avoided because bearing
High back-pressure and puncture, also, the drive circuit of switching tube is directly acted on after protection signal triggering, so as to improve the guarantor of system
Speed is protected, and then improves the antijamming capability and reliability of system.
Brief description of the drawings
Fig. 1 is the structural representation of the protection device of electromagnetic heating system according to an embodiment of the invention.
Fig. 2 is the circuit diagram of the protection device of electromagnetic heating system according to an embodiment of the invention.
Embodiment
Embodiments of the invention are described below in detail, the example of the embodiment is shown in the drawings, wherein from beginning to end
Same or similar label represents same or similar element or the element with same or like function.Below with reference to attached
The embodiment of figure description is exemplary, it is intended to for explaining the present invention, and is not considered as limiting the invention.
Below with reference to the accompanying drawings come the protection device of electromagnetic heating system that describes to propose according to embodiments of the present invention and have
Its electromagnetic heating system.
Fig. 1 is the structural representation of the protection device of electromagnetic heating system according to an embodiment of the invention.
In an embodiment of the present invention, as shown in figure 1, electromagnetic heating system can include resonance circuit, to resonance circuit
The drive circuit 20 that current rectifying and wave filtering circuit 10, the driving switch pipe Q of energy are switched on or off is provided, resonance circuit is by heating coil
L0, resonant capacitance C0 and switching tube Q compositions.
As shown in figure 1, the protection device of the electromagnetic heating system includes：Forward voltage surge detection circuit 30, electric current wave
Gush detection circuit 40, switching tube over-voltage detection circuit 50 and triggers circuit 60.
Wherein, forward voltage surge detection circuit 30 is more than first in the input voltage for detecting electromagnetic heating system and preset
Forward voltage surging signal is exported during voltage.Current surge detects circuit 40 and is more than the in the operating current for detecting switching tube Q
Output current surging signal during one predetermined current.Switching tube over-voltage detection circuit 50 is connected with switching tube Q colelctor electrode to examine
Measure output switch pipe overvoltage signal when switching tube Q collector voltage is more than the second predeterminated voltage.Triggers circuit 60 has the
One signal input part IN1, secondary signal input IN2, the 3rd signal input part IN3 and trigger output end OUT, the first signal are defeated
Enter to hold IN1 and the output end of forward voltage surge detection circuit 30 to be connected, secondary signal input IN2 and current surge detection electricity
Road 40 is connected, and the 3rd signal input part IN3 is connected with switching tube over-voltage detection circuit 50, trigger output end OUT and drive circuit
20 are connected, and triggers circuit 60 is triggered according to forward voltage surging signal, current surge signal and switching tube overvoltage signal output and protected
Signal is protected, to be turned off by the driving switch pipe Q of drive circuit 20.The default electricity of first predeterminated voltage, the first predetermined current and second
Pressure can be demarcated according to actual conditions.
Specifically, in the electromagnetic heating system course of work, electric main is converted to direct current by current rectifying and wave filtering circuit 10
Electric energy is provided to resonance circuit, controller output drive signal such as PPG (Programme Pulse Generator, may be programmed arteries and veins
Rushing generator) signal is to drive circuit 20, with by the driving switch pipe Q of drive circuit 20 turn-on and turn-off, by rectifying and wave-filtering
The direct current that circuit 10 exports is converted to high-frequency alternating current.Meanwhile circuit 30, current surge inspection are detected by forward voltage surge
Slowdown monitoring circuit 40 and switching tube over-voltage detection circuit 50 detect input voltage, the switching tube Q work of electromagnetic heating system in real time respectively
Make electric current (peak point current when i.e. system works) and switching tube Q collector voltage (voltage that i.e. switching tube Q is born).
If the input voltage of electromagnetic heating system is more than the first predeterminated voltage, or switching tube Q operating current is more than
First predetermined current, or switching tube Q collector voltage are more than the second predeterminated voltage, that is, input voltage surge, work are occurring
Undergone mutation as electric current or when switching tube Q severe overvoltages etc. are dangerous, the corresponding circuit that detects will export corresponding signal to touching
Power Generation Road 60, then, triggers circuit 60 export the drive circuit 20 that trigger protection signal directly acts on switching tube Q, so as to open
Pipe Q is closed to rapidly switch off, so as to which forward voltage surging signal and current surge signal can not only be avoided to be influenceed to caused by system,
And switching tube can be avoided to puncture because bearing too high back-pressure, also, directly act on switching tube after protection signal triggering
Drive circuit, so as to improve the protection speed of system, and then improve the antijamming capability and reliability of system.
According to one embodiment of present invention, as shown in Figure 1 or 2, the input of current surge detection circuit 40 passes through
First resistor R1 is connected to switching tube Q emitter stage with detection switch pipe Q operating current.Wherein, first resistor R1 can be
Constantan wire.
Specifically, as shown in Fig. 2 current surge detection circuit 40 can include：Second resistance R2,3rd resistor R3,
One diode D1 and first comparator U1, wherein, second resistance R2 and 3rd resistor R3 series connection, second resistance R2 one end and the
One resistance R1 one end is connected, and the second resistance R2 other end is connected with 3rd resistor R3 one end, and 3rd resistor R3's is another
End is connected with default power supply VCC, has first node J1 between the second resistance R2 other end and 3rd resistor R3 one end, the
One node J1 is connected by the first electric capacity C1 with ground GND.First diode D1 anode is connected with first node J1.First compares
Device U1 negative input end is connected with the first diode D1 negative electrode, first comparator U1 positive input terminal and the first reference voltage
REF1 is connected, and first comparator U1 output end is connected with the secondary signal input IN2 of triggers circuit 60.
Specifically, as shown in Fig. 2 the input of current surge detection circuit 40 is connected with the left end of constantan wire, constantan
Silk is connected with default power supply VCC, second resistance R2 and 3rd resistor R3 carries out series connection partial pressure, and voltage division signal is through the first diode D1
Input to first comparator U1 negative input end, first comparator U1 positive input terminal is adjustable first reference voltage REF1.
When electric current flows through constantan wire, the voltage of constantan wire left end is negative value, and the electric current flowed through is bigger, and negative sense amplitude is bigger, therefore the
Voltage at one node J1 is also lower, when voltage is less than the first reference voltage REF1, the U1 upsets of triggering first comparator, the
One comparator U1 output is changed into high level signal, i.e. current surge detection circuit 40 output current surge letter from low level signal
Number to triggers circuit 60, then, triggers circuit 60 exports trigger protection signal to drive circuit 20, to be driven by drive circuit 20
Dynamic switching tube Q shut-offs, so as to effectively avoid because electric current suddenly change impacts to system.
According to one embodiment of present invention, as shown in Figure 1 or 2, current rectifying and wave filtering circuit 10 includes rectifier bridge 11, absorbed
The corresponding connection exchange city of electric capacity C5, choking-winding L1 and storage capacitor C6, the first input end of rectifier bridge 11 and the second input
The both ends (L and N) of electricity, Absorption Capacitance C5 is connected in parallel between the first output end of rectifier bridge 11 and the second output end, choking-winding
L1 one end is connected with the first output end of rectifier bridge 11, and the choking-winding L1 other end is connected with storage capacitor C6 one end,
And the resonant capacitance C0 and heating coil L0 of parallel connection are connected to, the storage capacitor C6 other end and the second output end of rectifier bridge 11
It is connected.
Specifically, electric main can first pass through preposition EMC (Electro Magnetic Compatibility, electromagnetism
Compatibility) after module, then carry out rectifying and wave-filtering by current rectifying and wave filtering circuit 10 and carried with exporting galvanic current to resonance circuit
Power supply energy, wherein, choking-winding L1 and Absorption Capacitance C5 in current rectifying and wave filtering circuit 10 constitute filter circuit, to rectifier bridge 11
The direct current of the pulsation of output is filtered to export galvanic current, and storage capacitor C6 provides resonance energy for resonance circuit
Amount, its value can be 5 μ F.
Further, the input of forward voltage surge detection circuit 30 is connected with the first output end of rectifier bridge 11 to examine
Survey the input voltage of electromagnetic heating system.
Wherein, as shown in Fig. 2 forward voltage surge detection circuit 30 can include：4th resistance R4, the 5th resistance R5,
6th resistance R6, the second diode D2, the second comparator U2, wherein, the 4th resistance R4, the 5th resistance R5 and the 6th resistance R6 strings
Connection.4th resistance R4 one end is connected with the first output end of rectifier bridge 11, the 4th resistance the R4 other end and the 5th resistance R5
One end be connected, the 5th resistance R5 other end is connected with the 6th resistance R6 one end, the 6th resistance R6 other end ground connection
GND, and the 5th resistance R5 is parallel with the second electric capacity C2, the 6th resistance R6 and the 7th resistance R7 to connect and the 3rd electric capacity C3 simultaneously
Connection, has section point J2 between the 5th resistance R5 other end and the 6th resistance R6 one end.Second diode D2 anode
It is connected with section point J2.Second comparator U2 positive input terminal is connected with the second diode D2 negative electrode, the second comparator U2
Negative input end be connected with the second reference voltage REF2, the second comparator U2 output end and the first signal of triggers circuit 60 are defeated
Enter to hold IN1 to be connected.
Specifically, as shown in Fig. 2 the input signal of forward voltage surge detection circuit 30 is the rectified bridge of electric main
Half-wave voltage signal after 11 rectifications, the voltage signal carry out partial pressure through the 4th resistance R4, the 5th resistance R5 and the 6th resistance R6,
Voltage division signal is inputted to the second comparator U2 positive input terminal through the second diode D2, and the second comparator U2 negative input end is can
The the second reference voltage REF2 adjusted.Second electric capacity C2 can be high pressure ceramic disc capacitor, in parallel with the 5th resistance R5, with voltage wave
The interim rapid action of signal is gushed, so as to realize instantaneous short circuit.It is electric with the 6th again after 7th resistance R7 and the 3rd electric capacity C3 series connection
It is in parallel to hinder R6, to be filtered to voltage surge signal, improves the sensitivity of voltage surge signal.Second comparator U2 can be with
For high-speed comparator, the second comparator U2 carries out the conversion of low and high level according to the size of input voltage, such as when there is voltage
During surge, the voltage at section point J2 will be above the second reference voltage REF2, and now the second comparator U2 exports high level letter
Number, i.e., forward voltage surge detects the output voltage surging signal of circuit 30 to triggers circuit 60, and then, the output of triggers circuit 60 is touched
Protection signal is sent out to drive circuit 20, to be turned off by the driving switch pipe Q of drive circuit 20, so as to effectively avoid because of input voltage
Surge impacts to system.
According to one embodiment of present invention, as shown in Fig. 2 switching tube over-voltage detection circuit 50 can include：8th electricity
R8, the 9th resistance R9 and the 3rd comparator U3 are hindered, wherein, the 8th resistance R8 and the 9th resistance R9 series connection.The one of 8th resistance R8
End is connected with switching tube Q colelctor electrode, and the 8th resistance R8 other end is connected with the 9th resistance R9 one end, the 9th resistance R9's
The other end is grounded GND, and has the 3rd node J3 between the 8th resistance R8 other end and the 9th resistance R9 one end, the 9th electricity
Resistance R9 is parallel with the 4th electric capacity C4.3rd comparator U3 positive input terminal is connected with the 3rd node J3, and the 3rd comparator U3's is negative
Input is connected with the 3rd reference voltage REF3, the 3rd comparator U3 output end and the 3rd signal input part of triggers circuit 60
IN3 is connected.
Specifically, as shown in Fig. 2 the input signal of switching tube over-voltage detection circuit 50 is switching tube Q colelctor electrode
Voltage signal on the right side of voltage signal, and resonant capacitance C0.The voltage signal is carried out through the 8th resistance R8 and the 9th resistance R9
Partial pressure, voltage division signal are directly inputted into the 3rd comparator U3 positive input terminal, and the 3rd comparator U3 negative input end is adjustable
The 3rd reference voltage REF3.When switching tube Q overvoltages are serious, the voltage at the 3rd node J3 is by more than the 3rd reference of setting
Voltage REF3, the 3rd comparator U3 output high level signal, i.e. the output switch pipe overvoltage signal of switching tube over-voltage detection circuit 50
To triggers circuit 60, then, triggers circuit 60 exports trigger protection signal to drive circuit 20, to be driven by drive circuit 20
Switching tube Q is turned off, and so as to realize that switching tube overvoltage interruption is protected, is efficiently solved in correlation technique because of negative voltage surging signal
Earlier than forward voltage surging signal, and the too small caused leakage protection of time interval between two surging signals, switch tube are entered
Go and second protected again.
According to one embodiment of present invention, triggers circuit 60 can be three input nor gates.
Specifically, as shown in Fig. 2 three input nor gates can include：OR gate OR, nor gate NOR and the 3rd diode D3,
Wherein, OR gate OR first input end is connected with forward voltage surge detection circuit 30, OR gate OR the second input and electric current
Surge detection circuit 40 is connected, and nor gate NOR first input end is connected with switching tube over-voltage detection circuit 50, nor gate NOR
The second input be connected with OR gate OR output end, the 3rd diode D3 negative electrode AND OR NOT gate NOR output end is connected,
Three diode D3 anode is connected with drive circuit 20.
Specifically, as shown in Fig. 2 OR gate OR input detects the output end of circuit 30 with forward voltage surge respectively
It is connected with the output end of current surge detection circuit 40, when OR gate OR either input signal is high level signal, OR gate OR
High level signal will be exported.Nor gate NOR can be open-drain output nor gate, its input respectively with OR gate OR output end and
The output end of switching tube over-voltage detection circuit 50 is connected, when nor gate NOR either input signal is high level signal, or it is non-
Door NOR will export low level signal, and directly act on the drive circuit 20 of switching tube；Otherwise it is open-drain output, it exports electricity
Pressure signal is determined by external circuit.That is, three input nor gates can be divided into two-stage, the first order is OR gate OR input
Circuit 30 is detected for forward voltage surge and current surge detects circuit 40, and both enjoy same priority；The second level is first
Level output end and switching tube over-voltage detection circuit 50, make switching tube over-voltage detection circuit 50 enjoy higher priority, not only rise
The leakage protection of forward voltage surging signal, while the also second effect protected again are arrived.
Further, as shown in Fig. 2 drive circuit 20 can include：First NPN triode NPN1, the first PNP triode
PNP1, the second NPN triode NPN2, the 12nd resistance R12 and the 13rd resistance R13, wherein, the first NPN triode NPN1's
Colelctor electrode is connected by the tenth resistance R10 with default power supply VCC, the first NPN triode NPN1 base stage and triggers circuit 60
Output end is connected, and the first NPN triode NPN1 emitter stage is connected with switching tube Q base stage, the first PNP triode PNP1 hair
Emitter-base bandgap grading is connected with the first NPN triode NPN1 emitter stage, the first PNP triode PNP1 base stage and the first NPN triode
NPN1 base stage is connected, and the first PNP triode PNP1 colelctor electrode is grounded GND after being connected with switching tube Q emitter stage, and second
NPN triode NPN2 colelctor electrode is connected with the first NPN triode NPN1 base stage and the 11st resistance R11 one end respectively,
The 11st resistance R11 other ends are connected with default power supply VCC, the second NPN triode NPN2 grounded emitter GND, and the 12nd
Resistance R12 and the 13rd resistance R13 series connection, one end R12 of the 12nd resistance are connected with the second NPN triode NPN2 base stage,
The 12nd resistance R12 other end is connected with the 13rd resistance R13 one end, the 13rd resistance R13 other end and default electricity
Source VCC is connected, and has fourth node J4 between the 12nd resistance R12 other end and the 13rd resistance R13 one end, Section four
Point J4 is connected with controller.
Specifically, as shown in Fig. 2 the PPG signals of controller output are after the second NPN triode NPN2 is anti-phase, then pass through
Cross after the push-pull circuit that the first NPN triode NPN1 and the first PNP triode PNP1 are formed and act on switching tube Q ground level.
The input of push-pull circuit is also connected to the output end of three input nor gates by the 3rd diode D3.When overvoltage does not occur,
The output ends of three input nor gates be open-drain output, and the input of push-pull circuit is PPG signal functions in the second NPN triode
Signal after NPN2, the drive signal of normal work is provided for the switching tube Q in resonance circuit；When occurring over-pressed, three inputs
The output end of nor gate is low level signal, and the input of push-pull circuit is moved to low level by the 3rd diode D3 moments and believed
Number, now switching tube Q base signal is pulled low, and switching tube Q is closed, and stops power output, so as to realize the guarantor of switch tube
Shield.
That is, in an embodiment of the present invention, circuit 30 can be detected by forward voltage surge, current surge is examined
When slowdown monitoring circuit 40 and switching tube over-voltage detection circuit 50 detect the input voltage of electromagnetic heating system in real time respectively, system works
The voltage that peak point current and switching tube Q are born.There is input surge voltage, current break and switching tube when detecting wherein
When severe overvoltage etc. is potential dangerous, if reaching the triggering threshold values of respective comparator, comparator output high level signal, touch
Power Generation Road 60 exports trigger protection signal, and directly acts on switching tube Q drive circuit 20, with quick acting closing switch pipe
Q, so as to realize the protection of switch tube.
The protection device of electromagnetic heating system according to embodiments of the present invention, forward voltage surge detection circuit are detecting
The input voltage of electromagnetic heating system exports forward voltage surging signal, current surge detection circuit when being more than the first predeterminated voltage
The output current surging signal when the operating current for detecting switching tube is more than the first predetermined current, switching tube over-voltage detection circuit
The output switch pipe overvoltage signal when the collector voltage for detecting switching tube is more than the second predeterminated voltage, triggers circuit is according to just
To voltage surge signal, current surge signal and switching tube overvoltage signal output trigger protection signal, to be driven by drive circuit
Dynamic switching tube shut-off, so as to which forward voltage surging signal and current surge signal can not only be avoided to be influenceed to caused by system,
And switching tube can be avoided to puncture because bearing too high back-pressure, and the drive of switching tube is directly acted on after protection signal triggering
Dynamic circuit, so as to improve the protection speed of system, and then improves the antijamming capability and reliability of system.
In addition, embodiments of the invention also proposed a kind of electromagnetic heating system, it includes above-mentioned electromagnetic heating system
Protection device, wherein, electromagnetic heating system can be electromagnetic oven, electric cooker etc..
The electromagnetic heating system of the embodiment of the present invention, can not only by the protection device of above-mentioned electromagnetic heating system
Avoid forward voltage surging signal and current surge signal from being influenceed to caused by system, and switching tube can be avoided because bearing
High back-pressure and puncture, and the drive circuit of switching tube is directly acted on after protection signal triggering, so as to improve the guarantor of system
Speed is protected, and then improves the antijamming capability and reliability of system.
In the description of the invention, it is to be understood that term " " center ", " longitudinal direction ", " transverse direction ", " length ", " width ",
" thickness ", " on ", " under ", "front", "rear", "left", "right", " vertical ", " level ", " top ", " bottom " " interior ", " outer ", " up time
The orientation or position relationship of the instruction such as pin ", " counterclockwise ", " axial direction ", " radial direction ", " circumference " be based on orientation shown in the drawings or
Position relationship, it is for only for ease of and describes the present invention and simplify description, rather than indicates or imply that signified device or element must
There must be specific orientation, with specific azimuth configuration and operation, therefore be not considered as limiting the invention.
In addition, term " first ", " second " are only used for describing purpose, and it is not intended that instruction or hint relative importance
Or the implicit quantity for indicating indicated technical characteristic.Thus, define " first ", the feature of " second " can be expressed or
Implicitly include at least one this feature.In the description of the invention, " multiple " are meant that at least two, such as two, three
It is individual etc., unless otherwise specifically defined.
In the present invention, unless otherwise clearly defined and limited, term " installation ", " connected ", " connection ", " fixation " etc.
Term should be interpreted broadly, for example, it may be fixedly connected or be detachably connected, or integrally；Can be that machinery connects
Connect or electrically connect；Can be joined directly together, can also be indirectly connected by intermediary, can be in two elements
The connection in portion or the interaction relationship of two elements, limited unless otherwise clear and definite.For one of ordinary skill in the art
For, the concrete meaning of above-mentioned term in the present invention can be understood as the case may be.
In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", " specifically show
The description of example " or " some examples " etc. means specific features, structure, material or the spy for combining the embodiment or example description
Point is contained at least one embodiment or example of the present invention.In this manual, to the schematic representation of above-mentioned term not
Identical embodiment or example must be directed to.Moreover, specific features, structure, material or the feature of description can be with office
Combined in an appropriate manner in one or more embodiments or example.In addition, in the case of not conflicting, the skill of this area
Art personnel can be tied the different embodiments or example and the feature of different embodiments or example described in this specification
Close and combine.Although embodiments of the invention have been shown and described above, it is to be understood that above-described embodiment is example
Property, it is impossible to limitation of the present invention is interpreted as, one of ordinary skill in the art within the scope of the invention can be to above-mentioned
Embodiment is changed, changed, replacing and modification.
Claims (12)
1. a kind of protection device of electromagnetic heating system, it is characterised in that the electromagnetic heating system includes resonance circuit, to institute
State resonance circuit and the drive circuit that current rectifying and wave filtering circuit, the driving switch pipe of energy are switched on or off, the resonance circuit are provided
It is made up of heating coil, resonant capacitance and the switching tube, the protection device includes：
Forward voltage surge detects circuit, and the forward voltage surge detection circuit is detecting the defeated of the electromagnetic heating system
Enter when voltage is more than the first predeterminated voltage and export forward voltage surging signal；
Current surge detects circuit, and the current surge detection circuit is more than first in the operating current for detecting the switching tube
Output current surging signal during predetermined current；
Switching tube over-voltage detection circuit, the switching tube over-voltage detection circuit are connected with the colelctor electrode of the switching tube to detect
Output switch pipe overvoltage signal when being more than the second predeterminated voltage to the collector voltage of the switching tube；
Triggers circuit, the triggers circuit have the first signal input part, secondary signal input, the 3rd signal input part and touched
Output end is sent out, first signal input part is connected with the output end of forward voltage surge detection circuit, second letter
Number input is connected with current surge detection circuit, the 3rd signal input part and the switching tube over-voltage detection circuit
It is connected, the trigger output end is connected with the drive circuit, and the triggers circuit is according to the forward voltage surging signal, institute
Current surge signal and the switching tube overvoltage signal output trigger protection signal are stated, with by described in drive circuit driving
Switching tube turns off.
2. the protection device of electromagnetic heating system according to claim 1, it is characterised in that the current surge detection electricity
The input on road is connected to the emitter stage of the switching tube to detect the operating current of the switching tube by first resistor.
3. the protection device of electromagnetic heating system according to claim 2, it is characterised in that the first resistor is constantan
Silk.
4. the protection device of electromagnetic heating system according to claim 2, it is characterised in that the current surge detection electricity
Road includes：
The second resistance and 3rd resistor of series connection, one end of the second resistance is connected with one end of the first resistor, described
The other end of second resistance is connected with one end of the 3rd resistor, and the other end of the 3rd resistor is connected with default power supply,
There is first node, the first node passes through first between one end of the other end of the second resistance and the 3rd resistor
Electric capacity is connected to the ground；
First diode, the anode of first diode are connected with the first node；
First comparator, the negative input end of the first comparator are connected with the negative electrode of first diode, first ratio
Positive input terminal compared with device is connected with the first reference voltage, the second letter of the output end of the first comparator and the triggers circuit
Number input is connected.
5. the protection device of electromagnetic heating system according to claim 1, it is characterised in that the current rectifying and wave filtering circuit bag
Rectifier bridge, Absorption Capacitance, choking-winding and storage capacitor are included, the first input end of the rectifier bridge and the second input correspondingly connect
The both ends of electric main are connect, the Absorption Capacitance is connected in parallel between the first output end of the rectifier bridge and the second output end, institute
State one end of choking-winding with the first output end of the rectifier bridge to be connected, the other end of the choking-winding and energy storage electricity
One end of appearance is connected, and is connected to the resonant capacitance and heating coil of parallel connection, the other end of the storage capacitor and the rectification
Second output end of bridge is connected.
6. the protection device of electromagnetic heating system according to claim 5, it is characterised in that the forward voltage surge inspection
The input of slowdown monitoring circuit is connected with the first output end of the rectifier bridge to detect the input voltage of the electromagnetic heating system.
7. the protection device of electromagnetic heating system according to claim 6, it is characterised in that the forward voltage surge inspection
Slowdown monitoring circuit includes：
4th to the 6th resistance of series connection, one end of the 4th resistance is connected with the first output end of the rectifier bridge, described
The other end of 4th resistance is connected with one end of the 5th resistance, the other end and the 6th resistance of the 5th resistance
One end is connected, the other end of the 6th resistance ground connection, and the 5th resistor coupled in parallel has the second electric capacity, the 6th resistance with
The 7th resistance and the 3rd electric capacity of series connection are in parallel, have between the other end of the 5th resistance and one end of the 6th resistance
Section point；
Second diode, the anode of second diode are connected with the section point；
Second comparator, the positive input terminal of second comparator are connected with the negative electrode of second diode, second ratio
Negative input end compared with device is connected with the second reference voltage, the output end of second comparator and the first letter of the triggers circuit
Number input is connected.
8. the protection device of electromagnetic heating system according to claim 1, it is characterised in that the switching tube overvoltage detection
Circuit includes：
The 8th resistance and the 9th resistance of series connection, one end of the 8th resistance is connected with the colelctor electrode of the switching tube, described
The other end of 8th resistance is connected with one end of the 9th resistance, the other end ground connection of the 9th resistance, and the described 8th
There is the 3rd node, the 9th resistor coupled in parallel has the 4th electric capacity between one end of the other end of resistance and the 9th resistance；
3rd comparator, the positive input terminal of the 3rd comparator are connected with the 3rd node, and the 3rd comparator is born
Input is connected with the 3rd reference voltage, the output end of the 3rd comparator and the 3rd signal input part of the triggers circuit
It is connected.
9. the protection device of the electromagnetic heating system according to any one of claim 1-8, it is characterised in that the triggering
Circuit is three input nor gates.
10. the protection device of electromagnetic heating system according to claim 9, it is characterised in that the three inputs nor gate
Including：
OR gate, the first input end of the OR gate are connected with forward voltage surge detection circuit, and the second of the OR gate is defeated
Enter end with current surge detection circuit to be connected；
Nor gate, the first input end of the nor gate are connected with the switching tube over-voltage detection circuit, and the of the nor gate
Two inputs are connected with the output end of the OR gate；
3rd diode, the negative electrode of the 3rd diode are connected with the output end of the nor gate, the 3rd diode
Anode is connected with the drive circuit.
11. the protection device of electromagnetic heating system according to claim 10, it is characterised in that the drive circuit bag
Include：
First NPN triode, the colelctor electrode of first NPN triode are connected by the tenth resistance with default power supply, and described
The base stage of one NPN triode is connected with the output end of the triggers circuit, and the emitter stage of first NPN triode is opened with described
The base stage for closing pipe is connected；
First PNP triode, the emitter stage of first PNP triode are connected with the emitter stage of first NPN triode, institute
The base stage for stating the first PNP triode is connected with the base stage of first NPN triode, the colelctor electrode of first PNP triode
It is grounded after being connected with the emitter stage of the switching tube；
Second NPN triode, the colelctor electrode of second NPN triode respectively with the base stage of first NPN triode and
One end of 11 resistance is connected, and the 11st resistance other end is connected with the default power supply, second NPN triode
Grounded emitter；
The 12nd resistance and the 13rd resistance of series connection, one end of the 12nd resistance and the base of second NPN triode
Extremely be connected, the other end of the 12nd resistance is connected with one end of the 13rd resistance, the 13rd resistance it is another
End is connected with the default power supply, has the 4th between the other end of the 12nd resistance and one end of the 13rd resistance
Node, the fourth node are connected with controller.
12. a kind of electromagnetic heating system, it is characterised in that including the Electromagnetic Heating according to any one of claim 1-11
The protection device of system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610455122.9A CN107528289B (en) | 2016-06-20 | 2016-06-20 | Electromagnetic heating system and protection device thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610455122.9A CN107528289B (en) | 2016-06-20 | 2016-06-20 | Electromagnetic heating system and protection device thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107528289A true CN107528289A (en) | 2017-12-29 |
| CN107528289B CN107528289B (en) | 2020-04-03 |
Family
ID=60734084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610455122.9A Active CN107528289B (en) | 2016-06-20 | 2016-06-20 | Electromagnetic heating system and protection device thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107528289B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110492432A (en) * | 2019-08-19 | 2019-11-22 | 深圳市独尊科技开发有限公司 | A kind of high pressure excitation apparatus |
| CN110611500A (en) * | 2019-08-30 | 2019-12-24 | 深圳市鑫汇科股份有限公司 | Semiconductor switching device control circuit, method and device and electromagnetic heating device |
| CN111244887A (en) * | 2020-03-05 | 2020-06-05 | 深圳市鑫汇科股份有限公司 | Protection circuit and surge detection method |
| CN111509664A (en) * | 2020-05-09 | 2020-08-07 | 华瑞昇电子（深圳）有限公司 | Three-stage back-voltage protection circuit of chip special for electromagnetic oven |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201323447Y (en) * | 2008-12-12 | 2009-10-07 | 深圳市鑫汇科科技有限公司 | Voltage and current surge protection circuit for electromagnetic oven |
| CN101977045A (en) * | 2010-11-05 | 2011-02-16 | 美的集团有限公司 | Intelligent IGBT |
| CN205179404U (en) * | 2015-11-26 | 2016-04-20 | 佛山市顺德区美的电热电器制造有限公司 | IGBT's overvoltage crowbar among electromagnetic heating device and electromagnetic heating device |
| CN205846689U (en) * | 2016-06-20 | 2016-12-28 | 佛山市顺德区美的电热电器制造有限公司 | Electromagnetic heating system and protection device thereof |
-
2016
- 2016-06-20 CN CN201610455122.9A patent/CN107528289B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201323447Y (en) * | 2008-12-12 | 2009-10-07 | 深圳市鑫汇科科技有限公司 | Voltage and current surge protection circuit for electromagnetic oven |
| CN101977045A (en) * | 2010-11-05 | 2011-02-16 | 美的集团有限公司 | Intelligent IGBT |
| CN205179404U (en) * | 2015-11-26 | 2016-04-20 | 佛山市顺德区美的电热电器制造有限公司 | IGBT's overvoltage crowbar among electromagnetic heating device and electromagnetic heating device |
| CN205846689U (en) * | 2016-06-20 | 2016-12-28 | 佛山市顺德区美的电热电器制造有限公司 | Electromagnetic heating system and protection device thereof |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110492432A (en) * | 2019-08-19 | 2019-11-22 | 深圳市独尊科技开发有限公司 | A kind of high pressure excitation apparatus |
| CN110492432B (en) * | 2019-08-19 | 2024-03-26 | 深圳市独尊科技开发有限公司 | High-voltage excitation device |
| CN110611500A (en) * | 2019-08-30 | 2019-12-24 | 深圳市鑫汇科股份有限公司 | Semiconductor switching device control circuit, method and device and electromagnetic heating device |
| CN110611500B (en) * | 2019-08-30 | 2023-09-01 | 鑫汇科研究院(佛山)有限公司 | Semiconductor switching device control circuit, method and device and electromagnetic heating device |
| CN111244887A (en) * | 2020-03-05 | 2020-06-05 | 深圳市鑫汇科股份有限公司 | Protection circuit and surge detection method |
| CN111509664A (en) * | 2020-05-09 | 2020-08-07 | 华瑞昇电子（深圳）有限公司 | Three-stage back-voltage protection circuit of chip special for electromagnetic oven |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107528289B (en) | 2020-04-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107528289A (en) | Electromagnetic heating system and its protection device | |
| CN106026621B (en) | A kind of band avoids the IGBT drive circuit and detection method of short-circuit protection blind area | |
| CN103944355B (en) | A kind of constant-current switch power source based on CS short-circuit protection circuit | |
| CN109375087A (en) | A kind of protection circuit and method with high speed detection IGBT short trouble | |
| CN104868443B (en) | Automatic electric intelligent leakage protector | |
| CN104767173B (en) | Ground wire voltage exception earth leakage protective device is detected without IC optocouplers | |
| CN103857083B (en) | A kind of IGBT drive unit for electromagnetic heating system | |
| CN107394753B (en) | Soft turn-off protection circuit and method for power device | |
| CN1960102B (en) | Arc, earth leakage protection, and protection method | |
| CN205657421U (en) | Electromagnetic heating system and voltage surge protection device thereof | |
| CN205846689U (en) | Electromagnetic heating system and protection device thereof | |
| CN206250758U (en) | A kind of power tube multiple protective circuit of quick response | |
| CN205986093U (en) | Short -circuit protection circuit and have this short -circuit protection circuit's switching power supply | |
| CN208077039U (en) | A kind of ultrasonic atomizatio piece working control circuit | |
| CN108076546A (en) | Electromagnetic heating system and its protective device and guard method | |
| CN103825260B (en) | Power source surge protector | |
| CN103326323B (en) | Switching power supply protective circuit and method | |
| CN206004293U (en) | IGBT (insulated Gate Bipolar transistor) under-voltage protection circuit and induction cooker | |
| CN206993078U (en) | A kind of on-off circuit and the cooking apparatus with the on-off circuit | |
| CN205791448U (en) | A kind of rotation becomes excitation hiccup protections circuit and rotation becomes exciting circuit | |
| CN208207031U (en) | A kind of multimeter current foldback circuit based on IGBT | |
| CN207304968U (en) | Electromagnetic heater and the control circuit for reducing its stand-by power consumption | |
| CN206212319U (en) | Electromagnetic heating system and its protection device | |
| CN205657666U (en) | Protection circuit of switch tube and have its electromagnetic heating cooking equipment | |
| CN102931631B (en) | Output earth leakage protection device for high-voltage and direct-current power supply system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |