CN204012642U - For the protective circuit of electric heat mat - Google Patents
For the protective circuit of electric heat mat Download PDFInfo
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- CN204012642U CN204012642U CN201420505910.0U CN201420505910U CN204012642U CN 204012642 U CN204012642 U CN 204012642U CN 201420505910 U CN201420505910 U CN 201420505910U CN 204012642 U CN204012642 U CN 204012642U
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- 230000001681 protective effect Effects 0.000 title claims abstract description 36
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 66
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 66
- 239000010703 silicon Substances 0.000 claims abstract description 66
- 238000012360 testing method Methods 0.000 claims abstract description 43
- 238000010438 heat treatment Methods 0.000 claims description 31
- 238000004861 thermometry Methods 0.000 claims description 24
- 239000003990 capacitor Substances 0.000 claims description 22
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 12
- 101100156776 Oryza sativa subsp. japonica WOX1 gene Proteins 0.000 claims description 12
- 101150075910 SRT1 gene Proteins 0.000 claims description 12
- 239000011889 copper foil Substances 0.000 claims description 12
- 102100031786 Adiponectin Human genes 0.000 claims description 7
- 101000775469 Homo sapiens Adiponectin Proteins 0.000 claims description 7
- 230000001960 triggered effect Effects 0.000 claims description 7
- 101100503482 Arabidopsis thaliana FTSH5 gene Proteins 0.000 claims description 6
- 101150082136 VAR1 gene Proteins 0.000 claims description 6
- 230000008878 coupling Effects 0.000 claims description 6
- 238000010168 coupling process Methods 0.000 claims description 6
- 238000005859 coupling reaction Methods 0.000 claims description 6
- HEZMWWAKWCSUCB-PHDIDXHHSA-N (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carboxylic acid Chemical compound O[C@@H]1C=CC(C(O)=O)=C[C@H]1O HEZMWWAKWCSUCB-PHDIDXHHSA-N 0.000 claims description 4
- 238000001514 detection method Methods 0.000 claims description 4
- 230000000694 effects Effects 0.000 description 3
- 101100477605 Arabidopsis thaliana SRT2 gene Proteins 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 101000668165 Homo sapiens RNA-binding motif, single-stranded-interacting protein 1 Proteins 0.000 description 1
- 101000914514 Homo sapiens T-cell-specific surface glycoprotein CD28 Proteins 0.000 description 1
- 102100039692 RNA-binding motif, single-stranded-interacting protein 1 Human genes 0.000 description 1
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- 238000010586 diagram Methods 0.000 description 1
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- 230000000977 initiatory effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 108010039475 transforming growth factor alpha-Pseudomonas exotoxin A (40) Proteins 0.000 description 1
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Abstract
The utility model discloses a kind of protective circuit for electric heat mat, comprising: be serially connected in the fuse FUSIA on live wire; Fuse FUSIB; Controllable silicon SCR 1; Described controllable silicon SCR 1 anode connects live wire via fuse FUSIB; Described controllable silicon SCR 1 minus earth; Pwm signal testing circuit; Power supply VCC; And connect the coil of described relay R LY1, described pwm signal testing circuit and described power supply VCC, for in the time that described pwm signal testing circuit has detected pwm signal, control the coil that power supply VCC is connected to described relay R LY1, in the time that described pwm signal testing circuit detects without pwm signal, control power supply VCC and disconnect and the relay working state controlling circuit being connected of the coil of described relay R LY1; The utility model defencive function comprehensive and abundant, has improved security reliability when electric heat mat uses.
Description
Technical field
The utility model relates to a kind of fault secure circuit, is specially a kind of protective circuit for electric heat mat.
Background technology
Electric heat mat is the conventional heating installations of people, it is people's heating that suitable temperature can be provided in the situation that temperature is lower, it generally comprises blanket body, heater, power line and thermostat, realize the function of heating by the temperature of thermostat control heater, because electric heat mat is generally individual commodity, and directly contact with the person while use, therefore security reliability when electric heat mat uses is most important, Fig. 1 shows the structural representation of heater in prior art, shown in figure 1, heater comprises volume core 1, be wrapped in the line with heating function 2 on volume core 1, thermometry line 4, be placed in the insulating barrier 3 between line with heating function 2 and thermometry line 4, wherein thermometry line 4 can be regarded the thermistor of a positive temperature coefficient as, its resistance increases with temperature.The temperature control of electric heat mat of the prior art realizes generally 2 kinds of modes, wherein a kind of mode is: thermostat directly adopts temperature detect switch (TDS), when being greater than a certain temperature thermostat, temperature disconnects being connected between line with heating function and power line, in the time that temperature is less than a certain temperature, thermostat is connected being connected between line with heating function and power line, realize simple, but in the time that temperature detect switch (TDS) lost efficacy, temperature is not controlled, easily there is the phenomenon of the initiation fire due to excess Temperature, another mode is: thermostat is realized by single-chip microcomputer and relay, by adding single-chip microcomputer to make the function of product abundanter, but because complexity in circuits increases, be equivalent to increase fault point, improve the probability going wrong, simultaneously, if losing efficacy, single-chip microcomputer also can cause serious consequence, in addition, along with the development of built-in field, many microcontroller chips all have the function of output pwm signal as single-chip microcomputer, a kind of conventional PWM output signal mode is to control frequency and the duty ratio of pwm signal by timer, and flag bit is set, timer is exported PWM in the time that this flag bit is effective, remove immediately this flag bit, in the time that this flag bit is invalid, stop pwm signal output, this pwm signal way of output, microcontroller chip is run when flying or damaging, and it all can stop pwm signal output.
Summary of the invention
The utility model is for the proposition of above problem, and develops a kind of protective circuit for electric heat mat.
The technical solution of the utility model is:
A kind of protective circuit for electric heat mat, described electric heat mat comprises the single-chip microcomputer U2 of AC power cord, line with heating function HOTR1, thermometry line SRT1, mains switch PWR1, relay R LY1 and output pwm signal, and the contact of described relay R LY1, described line with heating function HOTR1 and the mutual series connection of described mains switch PWR1 are in AC-powered loop;
Described protective circuit comprises:
Be serially connected in the fuse FUSIA on live wire;
Fuse FUSIB;
Controllable silicon SCR 1; Described controllable silicon SCR 1 anode connects live wire via fuse FUSIB; Described controllable silicon SCR 1 minus earth;
Connect described single-chip microcomputer U2, the pwm signal testing circuit having or not for detection of pwm signal;
Power supply VCC;
And connect the coil of described relay R LY1, described pwm signal testing circuit and described power supply VCC, for in the time that described pwm signal testing circuit has detected pwm signal, control the coil that power supply VCC is connected to described relay R LY1, in the time that described pwm signal testing circuit detects without pwm signal, control power supply VCC and disconnect and the relay working state controlling circuit being connected of the coil of described relay R LY1;
In addition, described protective circuit also comprises:
Connect the relay Working state checking circuit of the contact of described relay R LY1;
And connection pwm signal testing circuit, relay Working state checking circuit and controllable silicon SCR 1, for detecting without pwm signal when pwm signal testing circuit, the first thyristor gating circuit of controllable silicon SCR 1, in closure state, is triggered in the contact that relay Working state checking circuit detects relay R LY1 simultaneously;
Further, described the first thyristor gating circuit also connects thermometry line SRT1, for triggering controllable silicon SCR 1 when above voltage is higher than certain value as thermometry line SRT1;
In addition, described protective circuit also comprises:
Fuse FUSIC;
Controllable silicon SCR 2; Described controllable silicon SCR 2 anodes connect live wire via fuse FUSIC; Described controllable silicon SCR 2 minus earths;
And connect controllable silicon SCR 2, for the second thyristor gating circuit that controllable silicon SCR 2 is triggered;
Further, pwm signal testing circuit comprises: resistance R 3, resistance R 6, resistance R 42, capacitor C 2, capacitor C 3, double diode D1 and switching tube Q2; The mutual coupling circuit in series of described resistance R 6 and capacitor C 3, this coupling circuit one end receives pwm signal, and the other end connects the serial connection point of double diode D1; The plus earth of described double diode D1; The negative electrode of described double diode D1 passes through capacitor C 2 ground connection, and by resistance R 3 connecting valve pipe Q2 base stages; Described switching tube Q2 base stage is by resistance R 42 ground connection; Described switching tube Q2 grounded emitter; Described switching tube Q2 collector electrode is connected with described relay working state controlling circuit;
Further, relay working state controlling circuit comprises: resistance R 1, resistance R 2, capacitor C 1 and switching tube Q1; Described switching tube Q1 base stage is connected described switching tube Q2 collector electrode with resistance R 1 by resistance R 2; Described switching tube Q1 emitter connects power supply VCC; The phase contact of described resistance R 2 and resistance R 1 is connected power supply VCC by capacitor C 1; Described switching tube Q1 collector electrode is connected with the coil of described relay R LY1;
In addition, described protective circuit also comprises power vd D; Described relay Working state checking circuit comprises: rectifier diode D13, resistance R 29, resistance R 35, resistance R 38, switching tube Q8 and resistance R 32; The contact of described rectifier diode D13 anodic bonding relay R LY1; Described rectifier diode D13 negative electrode is by resistance R 29, resistance R 35 and resistance R 38 ground connection of series connection mutually; The phase contact of described resistance R 35 and resistance R 38 is connected described switching tube Q8 base stage; Described switching tube Q8 grounded emitter; Described switching tube Q8 collector electrode connects power vd D by resistance R 32;
Further, described the first thyristor gating circuit comprises: diode D5, resistance R 30, resistance R 31, resistance R 39, switching tube Q9, resistance R 33, switching tube Q7, resistance R 5, diode D6, resistance R 9, diode D7, resistance R 7; Described diode D5 negative electrode connects described switching tube Q2 collector electrode; Described diode D5 anode is connected with the serial connection point of resistance R 29 and resistance R 35 by resistance R 30; Described diode D5 anode is also by resistance R 31 and resistance R 39 ground connection of series connection mutually; The serial connection point of described resistance R 31 and resistance R 39 is connected with the base stage of switching tube Q9; The grounded emitter of described switching tube Q9; Described switching tube Q9 collector electrode connects described switching tube Q7 base stage by resistance R 33; Described switching tube Q7 emitter is connected with the serial connection point of resistance R 29 and resistance R 35; Described switching tube Q7 collector electrode is connected the control utmost point of controllable silicon SCR 1 with diode D6 by the resistance R 5 of series connection mutually; Described diode D7 anodic bonding thermometry line SRT1, negative electrode connects the control utmost point of controllable silicon SCR 1 by resistance R 7; Described resistance R 9 is also connected between the control utmost point and negative electrode of controllable silicon SCR 1;
Further, described the second thyristor gating circuit comprises diode D9, resistance R 11 and resistance R 10; Described diode D9 anode receives controllable silicon SCR 2 triggering signals, and negative electrode connects the control utmost point of controllable silicon SCR 2 by resistance R 11; Described resistance R 10 is also connected between the control utmost point and negative electrode of controllable silicon SCR 2;
Further, described power supply VCC comprises: the Copper Foil fuse PF1 with the mutual series connection of fuse FUSIA in AC-powered loop and piezo-resistance VAR1, diode D2 and ac input end are by the ACDC power module IC1 a little that is connected in series of diode D2 connection copper foil fuse PF1 and piezo-resistance VAR1; Described power vd D comprises: resistance R 4 and input anode connect the DCDC power module U1 of the output plus terminal of ACDC power module IC1 by resistance R 4.
Owing to having adopted technique scheme, the protective circuit for electric heat mat that the utility model provides, can realize the protection of electric heat mat under multiple abnormal conditions, and defencive function comprehensive and abundant has improved security reliability when electric heat mat uses; Adopt analog hardware circuit, simple in structure, with low cost.
Brief description of the drawings
Fig. 1 is the structural representation of heater in prior art;
Fig. 2 is the structured flowchart of protective circuit described in the utility model;
Fig. 3 is the circuit theory diagrams of protective circuit described in the utility model.
Embodiment
A kind of protective circuit for electric heat mat as shown in Figures 2 and 3, described electric heat mat comprises the single-chip microcomputer U2 of AC power cord, line with heating function HOTR1, thermometry line SRT1, mains switch PWR1, relay R LY1 and output pwm signal, and the contact of described relay R LY1, described line with heating function HOTR1 and the mutual series connection of described mains switch PWR1 are in AC-powered loop; Described protective circuit comprises: be serially connected in the fuse FUSIA on live wire; Fuse FUSIB; Controllable silicon SCR 1; Described controllable silicon SCR 1 anode connects live wire via fuse FUSIB; Described controllable silicon SCR 1 minus earth; Connect described single-chip microcomputer U2, the pwm signal testing circuit having or not for detection of pwm signal; Power supply VCC; And connect the coil of described relay R LY1, described pwm signal testing circuit and described power supply VCC, for in the time that described pwm signal testing circuit has detected pwm signal, control the coil that power supply VCC is connected to described relay R LY1, in the time that described pwm signal testing circuit detects without pwm signal, control power supply VCC and disconnect and the relay working state controlling circuit being connected of the coil of described relay R LY1; In addition, described protective circuit also comprises: the relay Working state checking circuit that connects the contact of described relay R LY1; And connection pwm signal testing circuit, relay Working state checking circuit and controllable silicon SCR 1, for detecting without pwm signal when pwm signal testing circuit, the first thyristor gating circuit of controllable silicon SCR 1, in closure state, is triggered in the contact that relay Working state checking circuit detects relay R LY1 simultaneously; Further, described the first thyristor gating circuit also connects thermometry line SRT1, for triggering controllable silicon SCR 1 when above voltage is higher than certain value as thermometry line SRT1; In addition, described protective circuit also comprises: fuse FUSIC; Controllable silicon SCR 2; Described controllable silicon SCR 2 anodes connect live wire via fuse FUSIC; Described controllable silicon SCR 2 minus earths; And connect controllable silicon SCR 2, for the second thyristor gating circuit that controllable silicon SCR 2 is triggered; Further, pwm signal testing circuit comprises: resistance R 3, resistance R 6, resistance R 42, capacitor C 2, capacitor C 3, double diode D1 and switching tube Q2; The mutual coupling circuit in series of described resistance R 6 and capacitor C 3, this coupling circuit one end receives pwm signal, and the other end connects the serial connection point of double diode D1; The plus earth of described double diode D1; The negative electrode of described double diode D1 passes through capacitor C 2 ground connection, and by resistance R 3 connecting valve pipe Q2 base stages; Described switching tube Q2 base stage is by resistance R 42 ground connection; Described switching tube Q2 grounded emitter; Described switching tube Q2 collector electrode is connected with described relay working state controlling circuit; Further, relay working state controlling circuit comprises: resistance R 1, resistance R 2, capacitor C 1 and switching tube Q1; Described switching tube Q1 base stage is connected described switching tube Q2 collector electrode with resistance R 1 by resistance R 2; Described switching tube Q1 emitter connects power supply VCC; The phase contact of described resistance R 2 and resistance R 1 is connected power supply VCC by capacitor C 1; Described switching tube Q1 collector electrode is connected with the coil of described relay R LY1; In addition, described protective circuit also comprises power vd D; Described relay Working state checking circuit comprises: rectifier diode D13, resistance R 29, resistance R 35, resistance R 38, switching tube Q8 and resistance R 32; The contact of described rectifier diode D13 anodic bonding relay R LY1; Described rectifier diode D13 negative electrode is by resistance R 29, resistance R 35 and resistance R 38 ground connection of series connection mutually; The phase contact of described resistance R 35 and resistance R 38 is connected described switching tube Q8 base stage; Described switching tube Q8 grounded emitter; Described switching tube Q8 collector electrode connects power vd D by resistance R 32; Further, described the first thyristor gating circuit comprises: diode D5, resistance R 30, resistance R 31, resistance R 39, switching tube Q9, resistance R 33, switching tube Q7, resistance R 5, diode D6, resistance R 9, diode D7, resistance R 7; Described diode D5 negative electrode connects described switching tube Q2 collector electrode; Described diode D5 anode is connected with the serial connection point of resistance R 29 and resistance R 35 by resistance R 30; Described diode D5 anode is also by resistance R 31 and resistance R 39 ground connection of series connection mutually; The serial connection point of described resistance R 31 and resistance R 39 is connected with the base stage of switching tube Q9; The grounded emitter of described switching tube Q9; Described switching tube Q9 collector electrode connects described switching tube Q7 base stage by resistance R 33; Described switching tube Q7 emitter is connected with the serial connection point of resistance R 29 and resistance R 35; Described switching tube Q7 collector electrode is connected the control utmost point of controllable silicon SCR 1 with diode D6 by the resistance R 5 of series connection mutually; Described diode D7 anodic bonding thermometry line SRT1, negative electrode connects the control utmost point of controllable silicon SCR 1 by resistance R 7; Described resistance R 9 is also connected between the control utmost point and negative electrode of controllable silicon SCR 1; Further, described the second thyristor gating circuit comprises diode D9, resistance R 11 and resistance R 10; Described diode D9 anode receives controllable silicon SCR 2 triggering signals, and negative electrode connects the control utmost point of controllable silicon SCR 2 by resistance R 11; Described resistance R 10 is also connected between the control utmost point and negative electrode of controllable silicon SCR 2; Further, described power supply VCC comprises: the Copper Foil fuse PF1 with the mutual series connection of fuse FUSIA in AC-powered loop and piezo-resistance VAR1, diode D2 and ac input end are by the ACDC power module IC1 a little that is connected in series of diode D2 connection copper foil fuse PF1 and piezo-resistance VAR1; Described power vd D comprises: resistance R 4 and input anode connect the DCDC power module U1 of the output plus terminal of ACDC power module IC1 by resistance R 4.
Protective circuit described in the utility model also comprises relay R LY2; Described line with heating function and thermometry line have respectively two; Another line with heating function and thermometry line are respectively HOTL1 and SRT2; Contact each serial connection one line with heating function of described relay R LY1 and described relay R LY2; The contact of described relay R LY2 is by diode D14 contact resistance R29; The coil connecting valve pipe Q1 collector electrode of described relay R LY2; Same first thyristor gating circuit that connects of another thermometry line SRT2, the course of work of described relay R LY2 is identical with described relay R LY1.The contact of described relay R LY1, RLY2 is normally opened contact; Described switching tube Q1 adopts PNP transistor; Described switching tube Q2 adopts NPN transistor; Described switching tube Q2 adopts NPN transistor; Described switching tube Q7 adopts NPN transistor; Described switching tube Q8 adopts NPN transistor; Described switching tube Q9 adopts PNP transistor; Power supply VCC output voltage is 12V, and power vd D output voltage is 5V; Described fuse adopts two resistance temperature fuse P2R181J91; Ground connection is also distinguished at described thermometry line two ends, and connects power vd D by resistance.Described controllable silicon SCR 1 and SCR2 adopt BT168GW; Described single-chip microcomputer U2 adopts STM8S005 chip, and microcomputer development plate of the prior art all can be realized pwm signal output; The utility model can also comprise switching tube Q3, and described switching tube Q3 collector electrode connects the coil other end of described relay R LY1; Described switching tube Q3 grounded emitter; Described switching tube Q3 base stage receives the relay control signal of single-chip microcomputer U2 output.
Below in conjunction with accompanying drawing, the course of work of protective circuit described in the utility model is described: for pwm signal testing circuit and relay working state controlling circuit, pwm signal transfers to the serial connection point of double diode D1 through resistance R 6 and capacitor C 3 (capacitor C 3 plays every straight effect), described double diode D1 adopts BAV99W (two diode serial connections, there are 3 pins, be respectively serial connection point, the wherein anode of a diode, the negative electrode of another diode), double diode D1 and capacitor C 2 are carried out rectification to pwm signal and are obtained direct voltage, this direct voltage is applied on switching tube Q2 by resistance R 3, make switching tube Q2 conducting, test point TP45 in Fig. 3 is very low level of switching tube Q2 current collection, and then switching tube Q1 conducting, power supply VCC output voltage imposes on the coil of relay R LY1, before this, switching tube Q3 closure, the coil other end ground connection of relay R LY1, the closure of switching tube Q3 can realize by the high level signal of the IO mouth output of single-chip microcomputer U2, and then the coil electricity of relay R LY1, the closing of contact of relay R LY1, due to the contact of described relay R LY1, described line with heating function HOTR1 and the mutual series connection of described mains switch PWR1 be (closed electrical source switch PWR1 in the time that people use electric heat mat) in AC-powered loop, and then electric heat mat starts heating work, when without pwm signal, due to the existence of capacitor C 3, test point TP44 in Fig. 3 is low level, be that switching tube Q2 base stage is low level, switching tube Q2 cut-off, test point TP45 is high level, be that switching tube Q1 base stage is high level, switching tube Q2 cut-off, power supply VCC output voltage cannot impose on the coil of relay R LY1, correspondingly contact disconnects, the heating circuit of force disconnect electric heat mat, and then realize in the time that described pwm signal testing circuit has detected pwm signal, control the coil that power supply VCC is connected to described relay R LY1, in the time that described pwm signal testing circuit detects without pwm signal, controlling power supply VCC disconnects and being connected of the coil of described relay R LY1, as mentioning in the utility model background technology, in prior art, a kind of temperature control implementation of electric heat mat is: thermostat is realized by single-chip microcomputer and relay, it is the break-make of the direct control relay coil power of single-chip microcomputer, in the time that single-chip microcomputer lost efficacy, heating part is out of control, and the utility model is by pwm signal testing circuit and relay working state controlling circuit, can ensure in the time that single-chip microcomputer lost efficacy when output pwm signal (not) block system relay power supply, thereby disconnect the heating circuit of electric heat mat, realize the fail safe of single-chip microcomputer.For relay Working state checking circuit and the first thyristor gating circuit, in the time that electric heat mat is normally worked, the closing of contact of relay R LY1, the test point TP39 in Fig. 3, the common cathode limit that is diode D13 and D14 has the signal obtaining after alternating current halfwave rectifier, this signal resistance R29, the series connection bleeder circuit that resistance R 35 and resistance R 38 form is applied to switching tube Q8 base stage, collector electrode place that is switching tube Q8 at test point TP18 exists with AC power with signal frequently, in the time that this place exists with AC power with signal frequently, the contact that relay R LY1 is described is closed, in the time that this place does not exist with AC power with signal frequently, the contact that relay R LY1 is described disconnects, thereby can detect the current operating state of relay, and in the time that the detection of pwm signal testing circuit has pwm signal, test point TP45 is low level, and then test point TP54 is that diode D5 anode is low level, switching tube Q9, Q7 cut-off, controllable silicon SCR 1 is not worked, when coil one end of relay R LY1 disconnects and being connected of ground, pwm signal testing circuit does not detect pwm signal (being that single-chip microcomputer lost efficacy) simultaneously, and test point TP18 is that collector electrode place of switching tube Q8 exists with AC power with signal frequently, illustrate that the phenomenon of contact adhesion appears in relay R LY1 now, now test point TP45 place is high level, due to relay contact adhesion, test point TP54 place is also high level, switching tube Q9, Q7 conducting, and then the voltage at test point TP40 place (being the phase contact place of resistance R 29 and resistance R 35) is applied to the control utmost point of controllable silicon SCR 1 by switching tube Q7 and diode D6, trigger controllable silicon SCR 1 conducting, thereby fuse FUSIA and fuse FUSIB fusing, disconnect electric heat mat heating circuit, realize when single-chip microcomputer inefficacy, protection in the situation of relay contact adhesion simultaneously, and said process is all realized by analog circuit, it doesn't matter with single-chip microcomputer, greatly increase fail safe, in addition, electric heat mat in use, if line with heating function is overheated, the insulating barrier that can fuse between line with heating function and thermometry line, easily there is the situation of line with heating function and the short circuit of thermometry line, alternating current is added on line with heating function under normal circumstances, thermometry line is connected to the control utmost point of controllable silicon SCR 1 by diode, due to the dividing potential drop design of resistance R 7 and resistance R 9, the voltage that the control utmost point of controllable silicon SCR 1 applies is very little, be not enough to trigger controlled silicon conducting, if thermometry line and line with heating function short circuit, the voltage that the control utmost point of controllable silicon SCR 1 applies is very high, and then triggering controllable silicon SCR 1 conducting, thereby fuse FUSIA and fuse FUSIB fusing, disconnect electric heat mat heating circuit, realize the short-circuit protection of line with heating function and thermometry line.In addition, if the normal work of single-chip microcomputer was not lost efficacy, simultaneously the relay R LY1 coil other end has disconnected and being connected of ground, if now test point TP18 is the existence of collector electrode place and the signal of AC power with frequency of switching tube Q8, illustrate equally that the phenomenon of contact adhesion appears in relay R LY1 now, can trigger controllable silicon SCR 2 conductings by the second thyristor gating circuit so, and then fuse FUSIA and fuse FUSIC fusing, disconnect electric heat mat heating circuit, the second thyristor gating circuit can receive the silicon controlled trigger signal of single-chip I/O mouth output.
Power supply VCC described in the utility model comprises Copper Foil fuse PF1, Copper Foil width, thickness and the ampacity of described Copper Foil fuse PF1 designs by default blowout current, in the time that ACDC power module IC1 output end current is excessive, the electric current of Copper Foil fuse PF1 of flowing through can exceed default blowout current, and then Copper Foil fuse PF1 fusing, there is the effect of saving cost and space, protection rear class device; Described resistance R 4 can adopt current-limiting resistance in addition, and, in the time that DCDC power module U1 output end current is excessive, the electric current of the resistance R of flowing through 4 increases; make the increase of output power of current-limiting resistance R4; in the time exceeding resistance R 4 rated power, this resistance can burn, thereby plays the effect of protection rear class device.In addition; when Copper Foil fuse PF1 blows and relay contact occurs in the situation of adhesion; now power supply VCC and power vd D all do not export; if connection AC power cord, owing to can applying the voltage that alternating current dividing potential drop obtains on switching tube Q7 and Q9, therefore the first thyristor gating circuit can normally be worked; and then controllable silicon SCR 1 conducting that is triggered; fuse FUSIA and fuse FUSIB fusing, disconnect electric heat mat heating circuit, plays a protective role.
The protective circuit for electric heat mat that the utility model provides, can realize the protection of electric heat mat under multiple abnormal conditions, and defencive function comprehensive and abundant has improved security reliability when electric heat mat uses; Adopt analog hardware circuit, simple in structure, with low cost.
The above; it is only preferably embodiment of the utility model; but protection range of the present utility model is not limited to this; any be familiar with those skilled in the art the utility model disclose technical scope in; be equal to replacement or changed according to the technical solution of the utility model and inventive concept thereof, within all should being encompassed in protection range of the present utility model.
Claims (10)
1. the protective circuit for electric heat mat, described electric heat mat comprises the single-chip microcomputer U2 of AC power cord, line with heating function HOTR1, thermometry line SRT1, mains switch PWR1, relay R LY1 and output pwm signal, it is characterized in that, the contact of described relay R LY1, described line with heating function HOTR1 and the mutual series connection of described mains switch PWR1 are in AC-powered loop;
Described protective circuit comprises:
Be serially connected in the fuse FUSIA on live wire;
Fuse FUSIB;
Controllable silicon SCR 1; Described controllable silicon SCR 1 anode connects live wire via fuse FUSIB; Described controllable silicon SCR 1 minus earth;
Connect described single-chip microcomputer U2, the pwm signal testing circuit having or not for detection of pwm signal;
Power supply VCC;
And connect the coil of described relay R LY1, described pwm signal testing circuit and described power supply VCC, for in the time that described pwm signal testing circuit has detected pwm signal, control the coil that power supply VCC is connected to described relay R LY1, in the time that described pwm signal testing circuit detects without pwm signal, control power supply VCC and disconnect and the relay working state controlling circuit being connected of the coil of described relay R LY1.
2. the protective circuit for electric heat mat according to claim 1, is characterized in that described protective circuit also comprises:
Connect the relay Working state checking circuit of the contact of described relay R LY1;
And connection pwm signal testing circuit, relay Working state checking circuit and controllable silicon SCR 1, for detecting without pwm signal when pwm signal testing circuit, the first thyristor gating circuit of controllable silicon SCR 1, in closure state, is triggered in the contact that relay Working state checking circuit detects relay R LY1 simultaneously.
3. the protective circuit for electric heat mat according to claim 2, is characterized in that described the first thyristor gating circuit also connects thermometry line SRT1, for triggering controllable silicon SCR 1 when above voltage is higher than certain value as thermometry line SRT1.
4. the protective circuit for electric heat mat according to claim 1, is characterized in that described protective circuit also comprises:
Fuse FUSIC;
Controllable silicon SCR 2; Described controllable silicon SCR 2 anodes connect live wire via fuse FUSIC; Described controllable silicon SCR 2 minus earths;
And connect controllable silicon SCR 2, for the second thyristor gating circuit that controllable silicon SCR 2 is triggered.
5. the protective circuit for electric heat mat according to claim 3, is characterized in that pwm signal testing circuit comprises: resistance R 3, resistance R 6, resistance R 42, capacitor C 2, capacitor C 3, double diode D1 and switching tube Q2; The mutual coupling circuit in series of described resistance R 6 and capacitor C 3, this coupling circuit one end receives pwm signal, and the other end connects the serial connection point of double diode D1; The plus earth of described double diode D1; The negative electrode of described double diode D1 passes through capacitor C 2 ground connection, and by resistance R 3 connecting valve pipe Q2 base stages; Described switching tube Q2 base stage is by resistance R 42 ground connection; Described switching tube Q2 grounded emitter; Described switching tube Q2 collector electrode is connected with described relay working state controlling circuit.
6. the protective circuit for electric heat mat according to claim 5, is characterized in that relay working state controlling circuit comprises: resistance R 1, resistance R 2, capacitor C 1 and switching tube Q1; Described switching tube Q1 base stage is connected described switching tube Q2 collector electrode with resistance R 1 by resistance R 2; Described switching tube Q1 emitter connects power supply VCC; The phase contact of described resistance R 2 and resistance R 1 is connected power supply VCC by capacitor C 1; Described switching tube Q1 collector electrode is connected with the coil of described relay R LY1.
7. the protective circuit for electric heat mat according to claim 6, is characterized in that described protective circuit also comprises power vd D; Described relay Working state checking circuit comprises: rectifier diode D13, resistance R 29, resistance R 35, resistance R 38, switching tube Q8 and resistance R 32; The contact of described rectifier diode D13 anodic bonding relay R LY1; Described rectifier diode D13 negative electrode is by resistance R 29, resistance R 35 and resistance R 38 ground connection of series connection mutually; The phase contact of described resistance R 35 and resistance R 38 is connected described switching tube Q8 base stage; Described switching tube Q8 grounded emitter; Described switching tube Q8 collector electrode connects power vd D by resistance R 32.
8. the protective circuit for electric heat mat according to claim 7, is characterized in that described the first thyristor gating circuit comprises: diode D5, resistance R 30, resistance R 31, resistance R 39, switching tube Q9, resistance R 33, switching tube Q7, resistance R 5, diode D6, resistance R 9, diode D7, resistance R 7; Described diode D5 negative electrode connects described switching tube Q2 collector electrode; Described diode D5 anode is connected with the serial connection point of resistance R 29 and resistance R 35 by resistance R 30; Described diode D5 anode is also by resistance R 31 and resistance R 39 ground connection of series connection mutually; The serial connection point of described resistance R 31 and resistance R 39 is connected with the base stage of switching tube Q9; The grounded emitter of described switching tube Q9; Described switching tube Q9 collector electrode connects described switching tube Q7 base stage by resistance R 33; Described switching tube Q7 emitter is connected with the serial connection point of resistance R 29 and resistance R 35; Described switching tube Q7 collector electrode is connected the control utmost point of controllable silicon SCR 1 with diode D6 by the resistance R 5 of series connection mutually; Described diode D7 anodic bonding thermometry line SRT1, negative electrode connects the control utmost point of controllable silicon SCR 1 by resistance R 7; Described resistance R 9 is also connected between the control utmost point and negative electrode of controllable silicon SCR 1.
9. the protective circuit for electric heat mat according to claim 4, is characterized in that described the second thyristor gating circuit comprises diode D9, resistance R 11 and resistance R 10; Described diode D9 anode receives controllable silicon SCR 2 triggering signals, and negative electrode connects the control utmost point of controllable silicon SCR 2 by resistance R 11; Described resistance R 10 is also connected between the control utmost point and negative electrode of controllable silicon SCR 2.
10. the protective circuit for electric heat mat according to claim 7, it is characterized in that, described power supply VCC comprises: the Copper Foil fuse PF1 with the mutual series connection of fuse FUSIA in AC-powered loop and piezo-resistance VAR1, diode D2 and ac input end are by the ACDC power module IC1 a little that is connected in series of diode D2 connection copper foil fuse PF1 and piezo-resistance VAR1; Described power vd D comprises: resistance R 4 and input anode connect the DCDC power module U1 of the output plus terminal of ACDC power module IC1 by resistance R 4.
Priority Applications (1)
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CN201420505910.0U CN204012642U (en) | 2014-09-03 | 2014-09-03 | For the protective circuit of electric heat mat |
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CN201420505910.0U CN204012642U (en) | 2014-09-03 | 2014-09-03 | For the protective circuit of electric heat mat |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108762338A (en) * | 2018-08-14 | 2018-11-06 | 滁州国康医疗仪器有限公司 | Electric pad temperature control equipment |
CN108981181A (en) * | 2017-05-31 | 2018-12-11 | 芜湖美的厨卫电器制造有限公司 | Electric heater and its heating control apparatus and method |
-
2014
- 2014-09-03 CN CN201420505910.0U patent/CN204012642U/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108981181A (en) * | 2017-05-31 | 2018-12-11 | 芜湖美的厨卫电器制造有限公司 | Electric heater and its heating control apparatus and method |
CN108981181B (en) * | 2017-05-31 | 2023-10-31 | 芜湖美的厨卫电器制造有限公司 | Electric water heater and heating control device and method thereof |
CN108762338A (en) * | 2018-08-14 | 2018-11-06 | 滁州国康医疗仪器有限公司 | Electric pad temperature control equipment |
CN108762338B (en) * | 2018-08-14 | 2024-07-02 | 滁州国康医疗仪器有限公司 | Electric heating pad temperature control device |
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