Based Intelligent Control type DC low-voltage electroheating quilt/blanket and intelligence control circuit thereof
Technical field
The present invention relates to DC low-voltage electroheating quilt or electric blanket field, relate in particular to thermostatically controlled DC low-voltage electroheating quilt or electric blanket, specifically a kind of Based Intelligent Control type DC low-voltage electroheating quilt/blanket and intelligence control circuit thereof.
Background technology
At present traditional DC low pressure is temperature adjustable electrically heated to be reached blanket; When the bad or line fault of performance appears in the temperature sensing material of output, participate in thermoregulator main power section, then can make mistakes because of detection signal is in the misoperation state; This moment, output voltage raise; Cause back level load, out-of-control phenomenons such as rising occurred, bring bigger potential safety hazard to the user by body, blanket temperature.
Shown in Figure 1ly decide duty for Traditional use and recently regulate by the thermoregulation circuit of body, blanket temperature.The temperature that surpasses its setting when ambient temperature; Also or by body, blanket body take place when folding; The temperature value that each that sets section dutycycle voltage is corresponding will produce bigger variation, causes security incident easily, and the environment that this uses over blanket and blanket and the method for use all have higher requirement.So this circuit is not suitable for producing in batches and promoting the use of.
Shown in Figure 2ly be traditional thermoregulation circuit that attaches temperature sensing device on by the heating conductor of body, blanket body.When being risen by body, blanket temperature, temperature sensing device resistance attached to it (Positive and Negative Coefficient Temperature all can) also changes thereupon.This voltage variety is the level feedback circuit after R2 is sent to, and through comparing with reference voltage, the error voltage that output is corresponding with it also changes the dutycycle of the driving signal of MCU or drive IC output thereupon, thereby plays the effect of temperature adjustment.But this temperature sensing device receives the influence of present position and degree of adhesion; Can not respond in real time by the actual temperature variation of body, blanket body, and receive the influence of environment temperature very big, particularly when by body, when the blanket body takes place to fold; The temperature of induction point with differed very big by body, blanket body temperature inside value; The two differs greatly the dutycycle that the driving signal dutyfactor that causes the output of MCU or drive IC is corresponding with actual temperature value, and this will make that What is more by the temperature value of the non-induction point temperature value of body, blanket body above induction point; Also can make by the temperature value of body, blanket body to surpass its highest safety value that bears, cause serious security incident.So this scheme also is not suitable for producing in batches and promoting the use of owing to the restriction that influenced by method for using and service condition.
Address the above problem at present and mainly contain following two kinds of conventional methods:
1) method one
By body, a plurality of temperature detecting point of the inner increase of blanket body, the temperature sensing device that detects usefulness is serially connected, to reduce the radical of lead-in wire.Owing to increased a plurality of temperature detecting point, can cover heating part on a large scale, make the temperature value deviation of each point reduce.But this scheme is just because of having increased a plurality of fixing points; Corresponding also having increased by the technology difficulty of body, blanket body; And the fixing of temperature sensing device itself also is a more scabrous problem, and its uniformity and stability are difficult to be protected, so scheme is unfavorable for the real solution of problem.
2) method two
In by the control circuit of body, blanket body, the quantity that maximum temperature restriction can reduce temperature control point is set, playing the protective effect of control temperature upper limit, thereby can guarantee that by body, blanket body its temperature also can be limited in the safety value when the improper use.But this scheme still can not solve above-described non-uniform temperature and receive factor affecting such as position, method for using and the temperature imbalance problem that occurs; In addition; Also increased the possibility of over blanket and blanket appearance temperature control misoperation greatly; Influence is normal to be used, so also be not suitable for producing in batches and promoting the use of.
Summary of the invention
What the present invention will solve is the temperature-control circuit of existing over blanket and blanket and technical problems such as the temperature sampling device technology is complicated, cost is higher, poor reliability, aims to provide a kind of new intelligent DC low-voltage electroheating quilt and the control system of blanket.
Solving the problems of the technologies described above the technical scheme that is adopted is: the intelligence control circuit of DC low-voltage electroheating quilt/blanket comprises that resistance with the heater element of variable temperatures, automatic testing circuit, amplification and rectification circuit and MCU or drive IC, is characterized in that:
Described automatic testing circuit comprises master power switch pipe and the sampling resistor that is connected on the heater element major loop, and described sampling resistor is exported after the electric current of major loop is converted into the sampled voltage signal;
Described amplification and rectification circuit is exported with described sampled voltage signal amplification with after being shaped as the test voltage value;
Described MCU or drive IC compare through the test voltage value and the gear limit value of comparison circuit with amplification and rectification circuit output; Handle the control utmost point of the output duty cycle signals corresponding in back through logic circuit, PID and computing circuit again, form closed-loop control to the master power switch pipe with this gear.
Intelligence control circuit of the present invention; Can preestablish a dutycycle at the beginning of the start, generally speaking, the control utmost point driving signal that can set the master power switch pipe this moment is the maximum duty cycle state; Power supply power also reaches maximum, makes over blanket or electric blanket Fast Heating.After the heater element heating, its resistance changes with variation of temperature, makes the electric current of major loop that corresponding change also take place.Sampling resistor is gathered the current signal of major loop in real time, is transported to MCU or drive IC through amplification and rectification circuit.MCU or drive IC compare the gear limit value of this testing current value and initial adjustment, when this testing current value reaches this initial gear limit value, export the control utmost point of the duty cycle signals corresponding with this initial gear to the master power switch pipe.In heating process subsequently; When if the testing current value moves to the limit value of adjacent gear; MCU or drive IC are exported the control utmost point of the corresponding duty cycle signals of adjacent gear with this to the master power switch pipe; Thereby guarantee temperature by automatic constant between gear that sets and adjacent gear, play the automatic constant-temperature effect.
The intelligence control circuit of DC low-voltage electroheating quilt/blanket of the present invention adopts automated closed-loop intelligent constant-temperature system, under not influencing by the prerequisite of body, blanket bulk properties, has simplified by the process of body, blanket body, has reduced temperature sensing device production, processing cost.Ensured preferably by the temperature homogeneity of body, blanket body simultaneously, it has been controlled in the scope of a stability and safety.And, directly detecting the conductor resistance of heater element, its detected value can not receive the product method for using and fully by the influence of body, blanket folded body, this intelligent design, operability is higher, and cost is lower.
As further improvement of the present invention; Described heater element, master power switch pipe and sampling resistor are connected between the anode and ground of dc source successively; A control of series connection electrode resistance between the control utmost point of described master power switch pipe and the ground, the also external RC integrating circuit in described sampling resistor two ends can play the effect of buffering in the moment of starting shooting; Misoperation can be avoided, and the precision of current sampling signal can be improved.
According to the present invention, described amplification and rectification circuit comprises an amplifier circuit or a transistor circuit.
Further improve as of the present invention, described amplification and rectification circuit also comprises a preceding pole tension follower circuit again.Described voltage follower plays jamproof effect in order to isolate sampled signal.When heater element adopts the heater element of positive temperature coefficient, PTC element for example, described amplification and rectification circuit and sampled signal homophase; When heater element adopts the heater element of negative temperature coefficient, NTC element for example, described amplification and rectification circuit will carry out the output of covert back to sampled signal.
According to the present invention, described error comparison circuit is integrated in the inside of MCU or drive IC, perhaps is placed on MCU or drive IC.The external advantage of error comparison circuit is convenient the adjusting, and improves control accuracy.
Further improve as of the present invention, described heater element two ends also one of parallel connection absorb circuit again.This absorption circuit is used to improve the master power switch pipe and is turning on and off the voltage that is constantly born, and protection master power switch pipe is not breakdown.
According to the present invention, described absorption circuit comprises a pair of absorption diode and an absorption electric capacity, and described a pair of absorption diode negative electrode links to each other, and the anode cross-over connection is in the two ends of described absorption electric capacity and heater element.
According to the present invention; Described absorption circuit comprises an absorption resistance, an absorption diode and an absorption electric capacity; One end of one termination heater element of described absorption resistance and an end that absorbs electric capacity; Another termination of absorption resistance absorbs the other end of electric capacity and the negative electrode of absorption diode, the other end of the anode sending and receiving thermal element of absorption diode and the other end that absorbs electric capacity.
According to the present invention, described absorption circuit comprises an absorption resistance and a series circuit that absorbs the electric capacity formation.
According to the present invention, described master power switch pipe is wherein any of triode, MOSFET or IGBT.
The present invention also will provide a kind of Based Intelligent Control type DC low-voltage electroheating quilt/blanket; Comprise attaching plug, AC/DC power supply adaptor, many adjustable gears temperature controller, quilt/blanket body and intelligence control circuit; Described attaching plug is connected through the AC line with the AC/DC power supply adaptor; Described power supply adaptor is connected through the DC line with many adjustable gears temperature controller, and described many adjustable gears temperature controller is connected to by the bottom of/blanket body through the temperature controller load line, it is characterized in that described intelligence control circuit is arranged in the temperature controller; Comprise that resistance is with the heater element of variable temperatures, automatic testing circuit, amplification and rectification circuit and MCU or drive IC, wherein:
Described heater element is arranged in described quilt/blanket body;
Described automatic testing circuit comprises master power switch pipe and the sampling resistor that is connected on the heater element major loop, and described sampling resistor is exported after the electric current of major loop is converted into the sampled voltage signal;
Described amplification and rectification circuit is exported with described sampled voltage signal amplification with after being shaped as the test voltage value;
Described MCU or drive IC compare through the test voltage value and the gear limit value of comparison circuit with amplification and rectification circuit output; Handle the control utmost point of the output duty cycle signals corresponding in back through logic circuit, PID and computing circuit again, form closed-loop control to the master power switch pipe with this gear.
Description of drawings
Below in conjunction with accompanying drawing and embodiment the present invention is described further.
Fig. 1 is traditional temperature regulation circuit.
Fig. 2 is the constant-temperature circuit of traditional band temperature detection.
Fig. 3, Fig. 4, Fig. 5, be that the present invention adopts the intelligence control circuit of MOSFET as main switch.
Fig. 6, Fig. 7, Fig. 8, be that the present invention adopts the intelligence control circuit of transistor as main switch.
Fig. 9, Figure 10, Figure 11, be that the present invention adopts the intelligence control circuit of IGBT as main switch.
Figure 12 is the dutycycle control principle sketch map that the present invention adopts MCU or drive IC.
Figure 13 is the overall structure sketch map of Based Intelligent Control type DC low-voltage electroheating quilt/blanket of the present invention, comprises external wiring diagram and by body, blanket body internal wiring sketch map.
The specific embodiment
Embodiment one
Intelligence control circuit implementation of the present invention is just like Fig. 3, Fig. 4, shown in Figure 5, and its difference is that mainly the master power switch pipe is different with the absorption circuit between the power positive end DC+, and this body structure of intelligence control circuit is identical.
With reference to Fig. 4, described absorption circuit comprises a pair of absorption diode D1, D2 and an absorption capacitor C 1, and described a pair of absorption diode D1, D2 negative electrode link to each other, and the anode cross-over connection is in the two ends of described absorption capacitor C 1 and heater element.
Intelligence control circuit of the present invention comprises resistance with the heater element of variable temperatures, automatic testing circuit, amplification and rectification circuit and MCU or drive IC, among the figure, and R
CU1Equivalent resistance for heater element.Heater element can be various metal wires, heating line or heating sheet.
Described automatic testing circuit comprises master power switch pipe Q1 and sampling resistor R3; Described heater element, master power switch pipe Q1 and sampling resistor R3 are connected between the anode DC+ and ground of dc source successively; Described master power switch pipe Q1 adopts the MOSFET pipe, resistance R1 of series connection between its grid and the ground.The also external RC integrating circuit of connecting and constituting in described sampling resistor R3 two ends by resistance R 2 and capacitor C 2; The wherein source electrode of a termination MOSFET of resistance R 2 pipe and an end of resistance R 3; One end of another termination capacitor C 2 of resistance R 2, the other end of the other end connecting resistance R3 of capacitor C 2 and ground.
Described amplification and rectification circuit comprises follower U1-1, amplifier U1-2, peripheral resistance R 5-R8 and capacitor C 3.The common port of positive terminating resistor R2 of the input of follower U1-1 and capacitor C 2; The input negative terminal of follower U1-1 connects an end of its output and resistance R 5; One end of another termination capacitor C 3 of resistance R 5 and the input anode of amplifier U1-2; The other end ground connection of capacitor C 3, the input negative terminal connecting resistance R6 of amplifier U1-2 and an end of resistance R 7, the output of another termination amplifier U1-2 of resistance R 7 and an end of resistance R 8; The other end ground connection of resistance R 6 and MCU or drive IC, another termination MCU or the drive IC of resistance R 8.
In the present embodiment; Heater element adopts the material of ptc characteristics, and after DC low-voltage electroheating quilt and blanket energized, master power switch pipe Q1 is in the maximum duty cycle duty of setting; The Rcu resistance will increase with the rising of temperature thereupon, make the electric current of process sampling resistor R3 diminish thereupon.After resistance R 2, capacitor C 2, deliver to the back level at the sampled voltage signal that produces on the sampling resistor R3.Amplifier U1-2 imports MCU or drive IC after this sampled voltage signal is amplified shaping.When this detected value reaches the value that MCU or drive IC set; To export a gear control signal; Make the driving signal dutyfactor of the main power MOSFET tube G utmost point adjust to width shown in figure 12; Get into temperature constant state, the closed-loop adjustment of formation temperature variable realizes the function of automatic constant-temperature control with this.
When heater element adopts the heater element of negative temperature coefficient, NTC element for example, described amplification and rectification circuit will carry out the output of covert back to sampled signal, specifically can be through the input anode of amplifier U1-2 can be realized adjustment with the input negative terminal.
Circuits System of the present invention is simple, and volume is little, and cost is low, and technological feasibility is good, and does not receive the restriction of environment for use and method for using, so this scheme is fit to produce in batches and promote the use of.
With reference to Fig. 4; Described absorption circuit comprises an absorption resistance R9, an absorption diode D3 and an absorption capacitor C 4; One end of the termination heater element of described absorption resistance R9 and an end that absorbs capacitor C 4; Another termination of absorption resistance R9 absorbs the other end of capacitor C 4 and the negative electrode of absorption diode D3, the other end of the anode sending and receiving thermal element of absorption diode D3 and the other end that absorbs capacitor C 4.
With reference to Fig. 5, described absorption circuit comprises an absorption resistance R17 and a series circuit that absorbs capacitor C 7 formations, and wherein, the R17 of absorption circuit also can be 0.
Embodiment two
The embodiment two of intelligence control circuit of the present invention is like Fig. 6, Fig. 7 and shown in Figure 8, and three's difference only is that the master power switch pipe is different with the absorption circuit between the power positive end DC+, and this body structure of intelligence control circuit is identical.In the present embodiment, adopt the bipolarity transistor as the master power switch pipe.
With reference to Fig. 6, the structure of absorption circuit is identical with Fig. 4 embodiment, and the structure of testing circuit is also identical with Fig. 4 embodiment automatically, just substitutes MOSFET pipe Q2 with bipolarity transistor Q4.
Amplification and rectification circuit comprises triode Q4, resistance R 29, R30, R31 and R32; The resistance R 28 of the automatic testing circuit of one termination of resistance R 29 and the common port of capacitor C 11; The end of the other end connecting resistance R30 of resistance R 29 and the base stage of triode Q4; The other end of the emitter stage connecting resistance R30 of triode Q4 and ground, the colelctor electrode connecting resistance R31 of triode Q4 and an end of resistance R 32, another termination power V of resistance 31
CC, another termination MCU or the drive IC of resistance R 32.
After DC low-voltage electroheating quilt and blanket energized; Triode Q4 is in the maximum duty cycle duty of setting; The Rcu resistance will be with the rising of temperature change thereupon (heating conductors such as the heating line of ptc characteristics, heat-generating pipe, heating sheet, resistance will rise and increase with temperature; Heating conductors such as the heating line of NTC characteristic, heat-generating pipe, heating sheet, resistance will rise and reduce with temperature), make that the electric current through sampling resistor R27 changes thereupon.After resistance R 28 and capacitor C 11, deliver to the back level at the voltage signal that produces on the sampling resistor R27, carry out phse conversion and amplitude amplification,, and deliver to MCU or driver IC circuits with phase place and the amplitude requirement that satisfies closed loop circuit through amplification and rectification circuit.Reach value that MCU or drive IC set when the detected value of this signal this moment; With control signal of output with adjustable gears; Make the base drive signal dutycycle of triode Q4 adjust to width shown in figure 12; Get into temperature constant state, the closed-loop adjustment of formation temperature variable realizes the function of automatic constant-temperature control with this.
Circuits System of the present invention is simple, and volume is little, and cost is low, and technological feasibility is good, and does not receive the restriction of environment for use and method for using, so this scheme is fit to produce in batches and promote the use of.
With reference to Fig. 7, the structure of its absorption circuit is identical with Fig. 3 embodiment.
With reference to Fig. 8, the structure of its absorption circuit is identical with Fig. 5 embodiment.
Embodiment three
With reference to Fig. 9, Figure 10, Figure 11, for adopting the intelligent constant-temperature control circuit of IGBT as master power switch.。This embodiment operation principle can reference implementation example two said, difference is that this programme has increased an error comparison circuit in addition, described error comparison circuit is made up of comparator U4/U5/U6 and peripheral resistive element.The error comparison circuit.The advantage that the error comparison circuit independently is arranged on the outside of MCU or drive IC is convenient the adjusting, and improves control accuracy.
With reference to Figure 13; Based Intelligent Control type DC low-voltage electroheating quilt/blanket of the present invention; Comprise attaching plug 1, AC/DC power supply adaptor 3, many adjustable gears temperature controller 5, quilt/blanket body 7 and intelligence control circuit, be provided with the heater element 8 of resistance in described quilt/blanket body 7 with variable temperatures.Attaching plug 1 is connected through AC line 2 with AC/DC power supply adaptor 3, and power supply adaptor 3 is connected through DC line 4 with many adjustable gears temperature controller 5, and many adjustable gears temperature controller 5 is connected to by the bottom of/blanket body 7 through temperature controller load line 6.Described intelligence control circuit is arranged in the temperature controller 5, and its structure front was described, at this Ao Shu no longer.In temperature controller 5, also be provided with liquid crystal or charactron display circuit.The heater element of over blanket/blanket body interior is heat generating components, or detector unit.
The present invention adopts hexadecimal number word arithmetic and control mode to carry out over-temperature protection, and when over blanket and blanket were in hot environment or folding the use, MCU or control IC output protection level were closed the master power switch pipe, play the effect of protection; Simultaneously, liquid crystal or charactron display circuit output fault-signal, screen display fault character.
What should be understood that is: the foregoing description is just to explanation of the present invention; Rather than limitation of the present invention; Any innovation and creation that do not exceed in the connotation scope of the present invention all fall within protection scope of the present invention, like Figure 13; Contain connection, control and the display mode of over blanket/blanket, also all should fall into protection scope of the present invention.