CN104834334A - Double temperature control circuit - Google Patents
Double temperature control circuit Download PDFInfo
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- CN104834334A CN104834334A CN201510188674.3A CN201510188674A CN104834334A CN 104834334 A CN104834334 A CN 104834334A CN 201510188674 A CN201510188674 A CN 201510188674A CN 104834334 A CN104834334 A CN 104834334A
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Abstract
The invention discloses a double temperature control circuit, comprising a heating control unit, a lower limit temperature control unit and an upper limit temperature control unit. A heater of the heating control unit is controlled by a bidirectional thyristor and an optical coupler. An amplification circuit provides driving current to the optical coupler and is connected in parallel with a third relay. The amplification circuit and the third relay are jointly grounded via a normally open contact J1-1 and a normally closed contact J2-1. A normally open contact J3-1 of the third relay and the normally open contact J1-1 are connected in parallel. The lower limit temperature control unit comprises a first temperature sensor LM35D, a voltage comparator IC1, a potentiometer RP1 and a first relay. The voltage comparator IC1 controls the working state of the first relay J1 by comparing received voltages. The upper limit temperature control unit comprises a second temperature sensor LM35D, a voltage comparator IC2, a potentiometer RP2 and a second relay. The voltage comparator IC2 controls the working state of the second relay by comparing received voltages. According to the double temperature control circuit, the switching frequency of the heater is lowered, the operation stability of a system is improved, the service life of the system is prolonged, and impacts on a power grid are reduced to optimize the electromagnetic environment. The double temperature control circuit is significant in the temperature control field.
Description
Technical field
The present invention relates to a kind of control circuit, particularly relate to a kind of two temperature control circuit that temperature can be maintained in a pre-set interval.
Background technology
Temperature controls to be that the one often used in scientific experiment and production practices controls.Common one controls thinking, utilize voltage comparator, select the temperature sensor be suitable for, a road input using its voltage signal exported as comparer, the input of another road is obtained an applicable set potential, when the temperature varies, the output voltage of sensor changes thereupon, voltage comparator is by comparing the size of two groups of input voltages and the output determined is noble potential or electronegative potential, carry out the on off state of control heater according to this, reach the object of control temperature.Although this temperature control mode can realize the heating requirements being tending towards constant temperature, its shortcoming is the frequent opening and closing of well heater, does not singly reduce system lifetim and reliability, also pollutes electromagnetic environment.
And in most scientific experiment and production practices, the target temperature realized is needed to there is no strict constant temperature requirement, only need temperature to control in an appropriate scope, aforesaid temperature-control circuit controls temperature numerically a certain, and temperature cannot be realized to control the technical requirement in pre-set interval.Temperature-control circuit as a kind of in development and Design, after presetting, temperature can control in the interval of a requirement by it, thus the switching frequency of well heater can be reduced, improve stability and the life-span of system cloud gray model, and can reduce electromagnetic environment is optimized to the impact of electrical network, significant in domain of control temperature.
Embodiment
The object of the present invention is to provide a kind of reasonable in design, with low cost, stable, as required temperature can be controlled within the scope of a pre-set interval, thus the two temperature control circuit of the switching frequency of well heater can be reduced.
For realizing above-mentioned technical purpose, the present invention adopts following technical scheme:
A kind of two temperature control circuit, it comprises:
Heat control unit, it is provided with the bidirectional thyristor of well heater and control heater on off state, and a photo-coupler is connected with bidirectional thyristor, for providing trigger current for bidirectional thyristor; Photo-coupler and triode T1 and biasing resistor form an amplifying circuit, amplifying circuit provides drive current by launching very photo-coupler, this amplifying circuit is another in parallel with the 3rd relay, both the normally opened contact J1-1 of the first relay jointly through being arranged in series and normally closed contact J2-1 ground connection of the second relay, the normally opened contact J3-1 of the 3rd relay is in parallel with normally opened contact J1-1;
Lower limit temperature control module, it comprises the first temperature sensor LM35D, the voltage signal output end of the first temperature sensor LM35D is connected with the inverting input of a voltage comparator ic 1, and the in-phase input end of voltage comparator ic 1 provides a reference voltage by a potentiometer RP1, the output terminal of voltage comparator ic 1 is connected with a triode T2 base stage, both form on-off circuits, triode ON when voltage comparator ic 1 exports noble potential, and the load of this on-off circuit is the first relay J 1;
Ceiling temperature control module, it comprises the second temperature sensor LM35D, the voltage signal output end of the second temperature sensor LM35D is connected with the in-phase input end of a voltage comparator ic 2, and the inverting input of voltage comparator ic 2 provides a reference voltage by a potentiometer RP2, the output terminal of voltage comparator ic 2 is connected with a triode T3 base stage, both form on-off circuits, and triode ON when voltage comparator ic 2 exports noble potential, the load of this on-off circuit is the second relay J 2.
In the present invention, due to the temperature of the first temperature sensor LM35D and the second temperature sensor LM35D present position and output voltage signal all linearly, therefore RP1 can be utilized to set lower limit temperature t1 at lower limit temperature control module, and RP2 capping temperature t2 can be utilized at ceiling temperature control module, during practical application, the first temperature sensor LM35D and the second temperature sensor LM35D is placed in same position.
When in this environment during temperature < t1, voltage comparator ic 1 exports noble potential, make the first relay J 1 conducting, and voltage comparator ic 2 exports electronegative potential, makes the second relay J 2 still be in power failure state; Therefore in the circuit of heat control unit, normally opened contact J1-1 closes, normally closed contact J2-1 closes, and whole circuit forms path, and well heater is in running order; Meanwhile, because the 3rd relay J 3 place circuit forms path, its conducting and normally opened contact J3-1 is closed.
When temperature rise to > t1 but < t2 time, voltage comparator ic 1 exports electronegative potential, make the first relay J 1 become power failure state, voltage comparator ic 2 exports electronegative potential, makes the second relay J 2 still be in power failure state; Therefore in the circuit of heat control unit, normally opened contact J1-1 disconnects, normally closed contact J2-1 closes, but the 3rd relay J 3 is in conducting state, normally opened contact J3-1 is closed, and the whole circuit of heat control unit is still in channel status, and well heater works on.
When temperature rises to > t2, voltage comparator ic 2 exports noble potential, makes the second relay J 2 be in conducting state; Therefore in the circuit of heat control unit, normally closed contact J2-1 disconnects, and the circuit of heat control unit is in off state, well heater quits work, and temperature tops out, and meanwhile, because the 3rd relay J 3 becomes power failure state, normally opened contact J3-1 is disconnected.
When temperature drop to < t2 but > t1 time, voltage comparator ic 1 exports electronegative potential, make the first relay J 1 power failure state not yet, and the 3rd relay J 3 still maintains power failure state; Therefore in the circuit of heat control unit, normally opened contact J1-1 disconnects, normally opened contact J3-1 disconnects, and well heater still quits work, and temperature continues to reduce.
When temperature drops to < t1, voltage comparator ic 1 exports noble potential, make the first relay J 1 conducting, and voltage comparator ic 2 exports electronegative potential, makes the second relay J 2 still be in power failure state; In the circuit of heat control unit, normally opened contact J1-1 closes, and normally closed contact J2-1 closes, whole circuit forms path, and well heater enters duty again, and temperature raises, because the 3rd relay J 3 place circuit forms path, its conducting and normally opened contact J3-1 is closed.
As can be seen here, after the temperature of this control circui being preset in the interval of t1-t2, by the control to well heater, make actual temperature reciprocal be increased to t2 by t1, be then reduced to t1 by t2, temperature maintained in pre-set interval all the time.
The present invention has following beneficial effect: temperature can control in an interval according to presetting by it, the requirement to temperature conditions in many scientific experiments and production practices can be met, reduce again the switching frequency of well heater, improve stability and the life-span of system cloud gray model, and minimizing optimizes electromagnetic environment to the impact of electrical network, significant in domain of control temperature.In addition, its circuit is simple, with low cost, easily realizes.
Embodiment
A kind of two temperature control circuit disclosed by the invention, it is made up of heat control unit, lower limit temperature control module and ceiling temperature control module three part.
As shown in Figure 1, described heat control unit is provided with a well heater, the operating circuit of well heater is connected with bidirectional thyristor JZ, and bidirectional thyristor JZ is used for the switch working state of control heater; One photo-coupler Rcds is connected with bidirectional thyristor JZ, and photo-coupler Rcds is used for providing trigger current for bidirectional thyristor JZ; Described photo-coupler Rcds and triode T1 and biasing resistor R3, biasing resistor R4 form an amplifying circuit, this amplifying circuit provides drive current by the luminotron launching very photo-coupler Rcds, this amplifying circuit is another in parallel with the 3rd relay J 3, both the normally opened contact J1-1 of the first relay J 1 jointly through being arranged in series and normally closed contact J2-1 ground connection of the second relay J 2, the normally opened contact J3-1 of the 3rd relay J 3 is in parallel with normally opened contact J1-1.In foregoing circuit, when normally closed contact J2-1 closes, normally opened contact J3-1 and normally opened contact J1-1 at least one closed time, heat control unit can enter duty, i.e. the operating circuit formation loop and enter heated condition of well heater.
As shown in Figure 2, described lower limit temperature control module comprises the first temperature sensor LM35D in cut-in operation circuit, the voltage signal output end of the first temperature sensor LM35D is connected with the inverting input of a voltage comparator ic 1, and the in-phase input end of voltage comparator ic 1 is connected with the armature contact A1 of a potentiometer RP1, after potentiometer RP1 connects power supply, it can be voltage comparator ic 1 and provides a reference voltage, and this reference voltage is adjustable; The output terminal of voltage comparator ic 1 is connected with a triode T2 base stage, both form an on-off circuit, and between the first relay J 1 collector of being connected to triode T2 as the load of this on-off circuit and power supply, when voltage comparator ic 1 exports noble potential, triode T2 conducting, the first relay J 1 conducting.
As shown in Figure 3, described ceiling temperature control module comprises the second temperature sensor LM35D in cut-in operation circuit, the voltage signal output end of the second temperature sensor LM35D is connected with the in-phase input end of a voltage comparator ic 2, and the inverting input of voltage comparator ic 2 is connected with the armature contact A2 of a potentiometer RP2, after potentiometer RP2 connects power supply, it can be voltage comparator ic 2 and provides a reference voltage, and this reference voltage is adjustable; The output terminal of voltage comparator ic 2 is connected with a triode T3 base stage, both form an on-off circuit, and between the second relay J 2 collector of being connected to triode T3 as the load of this on-off circuit and power supply, when voltage comparator ic 2 exports noble potential, triode T3 conducting, the second relay J 2 conducting.
Embodiment: be described in 50 DEG C of-60 DEG C of intervals to utilize this control circui temperature.
Due to the first temperature sensor LM35D and the second temperature sensor LM35D, for existing temperature sensor product, the temperature of its present position and the voltage signal of output are all linearly, temperature often raises 1 DEG C, its output voltage raises 10 millivolts, potentiometer RP1 is adjusted in lower limit temperature control module, the voltage-to-ground of armature contact A1 is made to equal 500 millivolts, potentiometer RP2 is adjusted in ceiling temperature control module, the voltage-to-ground of armature contact A2 is made to equal 600 millivolts, first temperature sensor LM35D and the second temperature sensor LM35D is placed in by the same position of heating part, the workflow of this circuit is:
1, temperature-rise period.
1.1 when temperature is less than 50 DEG C.
The voltage signal that first temperature sensor LM35D exports is less than the in-phase input end voltage of voltage comparator ic 1, and the output terminal B1 of voltage comparator ic 1 is in noble potential, the first relay J 1 conducting; The voltage signal that second temperature sensor LM35D exports is less than the anti-phase input terminal voltage of voltage comparator ic 2, and the output terminal B2 of voltage comparator ic 2 is in electronegative potential, and the second relay J 2 is in power failure state; The state of the first relay J 1, second relay J 2 makes that the normally opened contact J1-1 in heat control unit is closed, normally closed contact J2-1 still closes, then the 3rd relay J 3 conducting is made, normally opened contact J3-1 closes, triode T1 conducting, light the luminotron of photoelectrical coupler Rcds, trigger bidirectional thyristor JZ, make well heater work, and keep this state until temperature is less than 60 DEG C.
1.2 work as temperature is greater than 50 DEG C, when being less than 60 DEG C.
When temperature equals 50 DEG C, the voltage signal that first temperature sensor LM35D exports is equal with the in-phase input end voltage of voltage comparator ic 1, voltage comparator ic 1 is in critical conditions, as long as temperature is a bit larger tham 50 DEG C, its anti-phase input terminal potential is higher than in-phase input end current potential, the output terminal B1 place of voltage comparator ic 1 presents electronegative potential, first relay J 1 becomes power failure state, although the normally opened contact J1-1 in heat control unit can be made to become off-state, but because of constant with the normally opened contact J3-1 state of its parallel connection, 3rd relay J 3 still conducting, well heater still works, continue up to temperature and be less than 60 DEG C.
1.3 when temperature is greater than 60 DEG C.
When temperature equals 60 DEG C, the voltage signal that second temperature sensor LM35D exports is equal with the anti-phase input terminal voltage of voltage comparator ic 2, voltage comparator ic 2 is in critical conditions, as long as temperature is a bit larger tham 60 DEG C, its in-phase input end current potential is higher than anti-phase input terminal potential, voltage comparator ic 2 output terminal B2 place presents noble potential, second relay J 2 conducting, the normally closed contact J2-1 in heat control unit is made to be in off-state, then the 3rd relay J 3 dead electricity, normally opened contact J3-1 is off-state, the luminotron of photoelectrical coupler Rcds extinguishes, bidirectional thyristor JZ is closed, well heater quits work.
2, temperature-fall period.
When 2.1 temperature are greater than 60 DEG C.
When temperature is greater than 60 DEG C, the voltage signal that first temperature sensor LM35D exports is greater than the in-phase input end voltage of voltage comparator ic 1, the output terminal B1 of voltage comparator ic 1 is in electronegative potential, first relay J 1 is in power failure state, the voltage signal that second temperature sensor LM35D exports is greater than the anti-phase input terminal voltage of voltage comparator ic 2, the output terminal B2 of voltage comparator ic 2 is in noble potential, and the second relay J 2 is in conducting state; Thus making the normally opened contact J1-1 in heat control unit, normally closed contact J2-1 and normal not contact J3-1 all be in off-state, triode T1 ends, and well heater does not work, and cooling continues.
2.2 temperature are less than 60 DEG C, when being greater than 50 DEG C.
The voltage signal that first temperature sensor LM35D exports is greater than the in-phase input end voltage of voltage comparator ic 1, the output terminal B1 of voltage comparator ic 1 is in electronegative potential, first relay J 1 is in power failure state, the voltage signal that second temperature sensor LM35D exports is less than the anti-phase input terminal voltage of voltage comparator ic 2, the output terminal B2 of voltage comparator ic 2 is in electronegative potential, and the second relay J 2 is in power failure state; Thus making the normally opened contact J1-1 in heat control unit and normally opened contact J3-1 be in off-state, normally closed contact J2-1 closes, and triode T1 ends, and well heater does not work, and cooling continues.
When 2.3 temperature are less than 50 DEG C.
The voltage signal that first temperature sensor LM35D exports is less than the in-phase input end voltage of voltage comparator ic 1, and the output terminal B1 of voltage comparator ic 1 is in noble potential, the first relay J 1 conducting; The voltage signal that second temperature sensor LM35D exports is less than the anti-phase input terminal voltage of voltage comparator ic 2, and the output terminal B2 of voltage comparator ic 2 is in electronegative potential, and the second relay J 2 is in power failure state; The state of the first relay J 1, second relay J 2 makes that the normally opened contact J1-1 in heat control unit is closed, normally closed contact J2-1 still closes, then the 3rd relay J 3 conducting is made, normally opened contact J3-1 closes, triode T1 conducting, light the luminotron of photoelectrical coupler Rcds, trigger bidirectional thyristor JZ, make well heater again enter duty.
As implied above, this circuit by control to well heater, make actual temperature reciprocal be increased to 60 DEG C by 50 DEG C, be then reduced to 50 DEG C by 60 DEG C, temperature maintained in 50 DEG C of default-60 DEG C of intervals all the time.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of heat control unit.
Fig. 2 is the circuit diagram of lower limit temperature control module.
Fig. 3 is the circuit diagram of ceiling temperature control module.
Claims (1)
1. a two temperature control circuit, is characterized in that, it comprises:
Heat control unit, it is provided with the bidirectional thyristor of well heater and control heater on off state, and a photo-coupler is connected with bidirectional thyristor, for providing trigger current for bidirectional thyristor; Photo-coupler and triode T1 and biasing resistor form an amplifying circuit, amplifying circuit provides drive current by launching very photo-coupler, this amplifying circuit is another in parallel with the 3rd relay, both the normally opened contact J1-1 of the first relay jointly through being arranged in series and normally closed contact J2-1 ground connection of the second relay, the normally opened contact J3-1 of the 3rd relay is in parallel with normally opened contact J1-1;
Lower limit temperature control module, it comprises the first temperature sensor LM35D, the voltage signal output end of the first temperature sensor LM35D is connected with the inverting input of a voltage comparator ic 1, and the in-phase input end of voltage comparator ic 1 provides a reference voltage by a potentiometer RP1, the output terminal of voltage comparator ic 1 is connected with a triode T2 base stage, both form on-off circuits, triode ON when voltage comparator ic 1 exports noble potential, and the load of this on-off circuit is the first relay J 1;
Ceiling temperature control module, it comprises the second temperature sensor LM35D, the voltage signal output end of the second temperature sensor LM35D is connected with the in-phase input end of a voltage comparator ic 2, and the inverting input of voltage comparator ic 2 provides a reference voltage by a potentiometer RP2, the output terminal of voltage comparator ic 2 is connected with a triode T3 base stage, both form on-off circuits, and triode ON when voltage comparator ic 2 exports noble potential, the load of this on-off circuit is the second relay J 2.
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| CN201510188674.3A CN104834334A (en) | 2015-04-13 | 2015-04-13 | Double temperature control circuit |
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| CN201510188674.3A CN104834334A (en) | 2015-04-13 | 2015-04-13 | Double temperature control circuit |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105759871A (en) * | 2016-02-23 | 2016-07-13 | 中国烟草总公司广东省公司 | Solar tobacco curing room temperature control circuit |
| CN105807816A (en) * | 2016-02-23 | 2016-07-27 | 中国烟草总公司广东省公司 | Baking apparatus temperature control circuit |
| CN109683643A (en) * | 2019-01-25 | 2019-04-26 | 创泽智能机器人股份有限公司 | A kind of temperature-control circuit |
| CN113916403A (en) * | 2021-10-15 | 2022-01-11 | 北京卫星环境工程研究所 | Dual-channel temperature detection device for thermal vacuum test |
| CN114791751A (en) * | 2022-05-10 | 2022-07-26 | 京东方科技集团股份有限公司 | Temperature signal acquisition circuit, light-emitting substrate and display device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105759871A (en) * | 2016-02-23 | 2016-07-13 | 中国烟草总公司广东省公司 | Solar tobacco curing room temperature control circuit |
| CN105807816A (en) * | 2016-02-23 | 2016-07-27 | 中国烟草总公司广东省公司 | Baking apparatus temperature control circuit |
| CN109683643A (en) * | 2019-01-25 | 2019-04-26 | 创泽智能机器人股份有限公司 | A kind of temperature-control circuit |
| CN113916403A (en) * | 2021-10-15 | 2022-01-11 | 北京卫星环境工程研究所 | Dual-channel temperature detection device for thermal vacuum test |
| CN114791751A (en) * | 2022-05-10 | 2022-07-26 | 京东方科技集团股份有限公司 | Temperature signal acquisition circuit, light-emitting substrate and display device |
| CN114791751B (en) * | 2022-05-10 | 2024-02-23 | 京东方科技集团股份有限公司 | Temperature signal acquisition circuit, light-emitting substrate and display device |
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