CN103294083B - PTC and NTC double-temperature-control circuit - Google Patents

Abstract

The invention discloses a PTC and NTC double-temperature-control circuit and temperature control method of the PTC and NTC double-temperature-control circuit. The PTC and NTC double-temperature-control circuit comprises a heating element and a controller, wherein the heating element comprises an induction wire, an NTC layer and a PTC heating wire, and the controller comprises a fuse, a capacitance resisting and voltage relief circuit, an indicating lamp circuit, a power source voltage detecting circuit, a synchronous signal circuit, a high-frequency square wave emitting circuit, a high-frequency square wave receiving circuit, an NTC voltage detecting circuit, an NTC load detecting circuit, a PTC load detecting circuit, a protection thyristor, an operation thyristor, an operation thyristor short circuit detecting circuit and a central processing unit. According to the PTC and NTC double-temperature-control circuit and temperature control method of the PTC and NTC double-temperature-control circuit, the operation thyristor and the protection thyristor are matched with each other, when the operation thyristor is out of control, the protection thyristor can cut off a power source in time and synchronously checks the operating states of the PTC heating wire and the induction wire, and failure detecting ability is stronger.

Description

PTC and NTC dual control circuit temperature

Technical field

The present invention relates to technical field of temperature control, particularly a kind of PTC and NTC dual control circuit temperature and temperature control method thereof.

Background technology

At present, traditional heating pad of home market, the temperature-control circuit cardinal principle of the electric heating products such as electric blanket is the break-make of the switch of control temperature, this temperature-control circuit principle is simple, but in fault detect, there is obvious deficiency, and the switch of control temperature is often on off operating mode, therefore unavoidably can be out of control, and the temperature-control circuit of prior art does not focus on switch detection out of control, cause product to be heated always, until line with heating function burns out, cause unnecessary casualties and property loss.

Summary of the invention

(1) technical matters that will solve

Object of the present invention is exactly the shortcoming that the temperature-control circuit that will overcome prior art does not focus on switch detection out of control, aims to provide a kind of PTC(positive temperature coefficient (PTC) strengthening fault-detecting ability) with NTC(negative temperature coefficient) dual control circuit temperature and temperature control method thereof.

(2) technical scheme

For achieving the above object, PTC and NTC dual control circuit temperature of the present invention, comprise heater and controller, described heater comprises the line of induction, NTC layer and PTC line with heating function, described controller comprises fuse, capacitance-resistance voltage reduction circuit, indicator light circuit, voltage detection circuit, synchronous signal circuit, high frequency square wave sends circuit, high frequency square wave receiving circuit, NTC voltage detecting circuit, NTC load detecting circuit, PTC load detecting circuit, protection controllable silicon, work controllable silicon, work controllable silicon short-circuit detecting circuit and central processing unit, described fuse connects described capacitance-resistance voltage reduction circuit simultaneously, described voltage detection circuit, described synchronous signal circuit and described protection controllable silicon, described capacitance-resistance voltage reduction circuit, described indicator light circuit, described voltage detection circuit is connected central processing unit with described synchronous signal circuit, and described central processing unit is used for Control protection controllable silicon, high frequency square wave sends circuit, NTC voltage detecting circuit, NTC load detecting circuit, PTC load detecting circuit and work controllable silicon, described work controllable silicon is for control PTC line with heating function, described high frequency square wave sends circuit for receiving NTC layer temperature variation, detect the whether short circuit of the described line of induction simultaneously, described central processing unit sends circuit by high frequency square wave and exports high-frequency signal, gets back to high frequency square wave receiving circuit by the described line of induction.

Further, described central processing unit and the reference resistance being provided with voltage sample circuit between zero line and connect with voltage sample circuit.

Further, described NTC voltage detecting circuit is converted into digital signal for the change of the voltage detecting NTC layer and cause, and compares with described central processing unit internal reference.

The present invention also provides a kind of PTC and NTC dual control circuit temperature temperature control method, comprises the following steps:

Carry out program initialization;

Carry out fault detect, the whether short circuit of testing controllable silicon, in this way, then closes output, as no, then protects controllable silicon work, fuse wire;

Judge whether timing arrives, and if so, then closes output;

Judge whether preheating, if so, then NTC preheat temperature value compares in preheating operation parameter and central processing unit, and if not, then in normal operational parameters and central processing unit, NTC temperature value contrasts;

Above-mentioned pre-thermal result is used for judging whether to reach the corresponding gear temperature of NTC, if so, then closes output, if not, then opens output.

(3) beneficial effect

Compared with prior art; technical scheme of the present invention has the following advantages: work controllable silicon and protection controllable silicon cooperatively interact, and after work controllable silicon is out of control, protection controllable silicon can be cut off the electricity supply in time; synchronous detection line with heating function and line of induction working condition, fault-detecting ability is stronger.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of PTC and NTC dual control circuit temperature temperature control method of the present invention;

Fig. 2 is the schematic block circuit diagram of PTC and NTC dual control circuit temperature of the present invention;

Fig. 3 is the circuit theory diagrams of PTC and NTC dual control circuit temperature of the present invention;

Fig. 4 is the schematic block circuit diagram of the embodiment two of PTC and NTC dual control circuit temperature of the present invention.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples for illustration of the present invention, but are not used for limiting the scope of the invention.

Embodiment one

As depicted in figs. 1 and 2, PTC and NTC dual control circuit temperature of the present invention, comprise heater and controller, described heater comprises the line of induction, NTC layer and PTC line with heating function, described controller comprises fuse, capacitance-resistance voltage reduction circuit, indicator light circuit, voltage detection circuit, synchronous signal circuit, high frequency square wave sends circuit, high frequency square wave receiving circuit, NTC voltage detecting circuit, NTC load detecting circuit, PTC load detecting circuit, protection controllable silicon, work controllable silicon, work controllable silicon short-circuit detecting circuit and central processing unit, described fuse connects described capacitance-resistance voltage reduction circuit simultaneously, described voltage detection circuit, described synchronous signal circuit and described protection controllable silicon, described capacitance-resistance voltage reduction circuit, described indicator light circuit, described voltage detection circuit is connected central processing unit with described synchronous signal circuit, and described central processing unit is used for Control protection controllable silicon, high frequency square wave sends circuit, NTC voltage detecting circuit, NTC load detecting circuit, PTC load detecting circuit and work controllable silicon, described work controllable silicon is for control PTC line with heating function, described high frequency square wave sends circuit for receiving NTC layer temperature variation, detect the whether short circuit of the described line of induction simultaneously, described central processing unit sends circuit by high frequency square wave and exports high-frequency signal, high frequency square wave receiving circuit is got back to by the described line of induction, if damaging appears in the line of induction, then high-frequency signal cannot feed back to central processing unit, closedown exports by central processing unit, and circuit theory diagrams as shown in Figure 3.

Described central processing unit and the reference resistance being provided with voltage sample circuit between zero line and connect with voltage sample circuit.

Described NTC voltage detecting circuit is converted into digital signal for the change of the voltage detecting NTC layer and cause, and compares with described central processing unit internal reference.

The present invention also provides a kind of PTC and NTC dual control circuit temperature temperature control method, comprises the following steps:

Carry out program initialization;

Carry out fault detect, the whether short circuit of testing controllable silicon, in this way, then closes output, as no, then protects controllable silicon work, fuse wire;

Judge whether timing arrives, and if so, then closes output;

Judge whether preheating, if so, then NTC preheat temperature value compares in preheating operation parameter and central processing unit, and if not, then in normal operational parameters and central processing unit, NTC temperature value contrasts;

Above-mentioned pre-thermal result is used for judging whether to reach the corresponding gear temperature of NTC, if so, then closes output, if not, then opens output.

Resistance and capacitances in series step-down adopt voltage stabilizing diode voltage stabilizing composition capacitance-resistance voltage reduction circuit to provide stable voltage to central processing unit.

Supply voltage monitoring is synchronous for the change and voltage sampling detecting supply voltage at any time, accurate to reach temperature control.

It is as synchronous in the modules such as timing, work controlled silicon conducting and power source change that synchronous signal circuit makes central processing unit inner.

NTC layer is by the change change in resistance of temperature, by the line of induction, central processing unit detects that the change of NTC resistance relevant voltage changes into digital signal and internal reference compares (compare and complete in central processing unit inside).Simultaneously NTC load detecting is for detecting PTC line with heating function and the NTC line of induction is inner or terminals whether short circuit, and the voltage difference that central processing unit detects judges load whether problem.

Embodiment two

As shown in Figure 3 and Figure 4, the present embodiment is substantially identical with embodiment one, difference is, high frequency square wave in embodiment one sends circuit and high frequency square wave receiving circuit replaces with the first voltage detecting circuit and the second voltage detecting circuit respectively, in the mode of the voltage ratio examining line of induction two ends, first voltage detecting circuit and the second voltage detecting circuit judge whether the line of induction disconnects, thus also reach the object detecting line of induction duty.

In sum, above-mentioned embodiment is not restricted embodiment of the present invention, and the modification that all those skilled in the art carry out on the basis of flesh and blood of the present invention or equivalent deformation, all at technology category of the present invention.

Claims (3)

1. a PTC and NTC dual control circuit temperature, is characterized in that: comprise heater and controller, and described heater comprises the line of induction, NTC layer and PTC line with heating function, described controller comprises fuse, capacitance-resistance voltage reduction circuit, indicator light circuit, voltage detection circuit, synchronous signal circuit, high frequency square wave sends circuit, high frequency square wave receiving circuit, NTC voltage detecting circuit, NTC load detecting circuit, PTC load detecting circuit, protection controllable silicon, work controllable silicon, work controllable silicon short-circuit detecting circuit and central processing unit, described fuse connects described capacitance-resistance voltage reduction circuit simultaneously, described voltage detection circuit, described synchronous signal circuit and described protection controllable silicon, described capacitance-resistance voltage reduction circuit, described indicator light circuit, described voltage detection circuit is connected central processing unit with described synchronous signal circuit, and described central processing unit is used for Control protection controllable silicon, high frequency square wave sends circuit, NTC voltage detecting circuit, NTC load detecting circuit, PTC load detecting circuit and work controllable silicon, described work controllable silicon is for control PTC line with heating function, described high frequency square wave sends circuit for receiving NTC layer temperature variation, detect the whether short circuit of the described line of induction simultaneously, described central processing unit sends circuit by high frequency square wave and exports high-frequency signal, gets back to high frequency square wave receiving circuit by the described line of induction.

2. PTC and NTC dual control circuit temperature as claimed in claim 1, is characterized in that: described central processing unit and the reference resistance being provided with voltage sample circuit between zero line and connect with voltage sample circuit.

3. PTC and NTC dual control circuit temperature as claimed in claim 1, is characterized in that: described NTC voltage detecting circuit is converted into digital signal for the change of the voltage detecting NTC layer and cause, and compares with described central processing unit internal reference.