JPH0367933A - temperature control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a temperature control device for electric carpets, floor heating, etc. used in general households.

2. Description of the Related Art The structure of a conventional temperature control device, for example, a temperature control device for an electric carpet, will be explained with reference to FIGS. 3 and 4. FIG. 3 is a diagram showing the constituent countries of the device, and FIG. 4 is a diagram showing changes over time in temperature control of the device. First, the circuit configuration will be explained with reference to FIG.

An AC power source 1, a relay 2 serving as a switching means, and a heater 3 are connected in series. 4 is a relay driving transistor.

The carpet surface temperature signal is converted into a detected temperature voltage VT by a temperature detection circuit 5, and compared with a set temperature voltage VR by a comparator 6 serving as comparison means. The higher the detected temperature, the higher the detected temperature voltage VT. In recent years, various efforts have been made to improve the rise characteristics of the control temperature when the power is turned on.

In this example, instead of a conventional 700W heater, a 900W heater is used.
A W heater is used. FIG. 4 shows the temperature control at this time. When the power is turned on, full power of 900W is applied for a certain period of time. Maximum ON time and OFF of heater 3 when temperature is stable
The minimum time is counted by an ON time timer 7 and an OFF time timer 8, respectively. In the control unit 9, even if the detected temperature voltage VT<the set temperature voltage VR, if the ON time quimuff counts up (maximum ON time), at least until the next OFF time timer 8 counts up ( (minimum OFF time), duty control is performed so that the heater 3 is turned off. If the maximum ON time is 3 minutes and 7 seconds and the minimum OFF time is 53 seconds, the instantaneous maximum power is 900W when the temperature is stable, but the average power is approximately 70W at the maximum.
It becomes 0Wh. This duty is set to the normal "strong" temperature, and is designed not to exceed the "strong" temperature when the temperature is stable.

As shown in Figure 4 (a), during normal stable conditions, the maximum ON time.

Although the control is performed regardless of the minimum OFF time, Fig. 4(b)
When the heat dissipation is large as in
Duty control is performed using the F minimum time.

Problem to be Solved by the Invention However, as shown in FIG. 4(b), the energization is controlled by the ON time timer 7 and the OFF time timer 8, and when the heat is kept locally, the ON time timer 7 ,
When the OFF time timer 8 malfunctions due to noise or the like, the comparator 6 does not control it, and the local heat insulating section is abnormally heated, causing discoloration and burning on the carpet body and the heat insulating material, posing a safety issue.

The present invention solves the above problems and improves the maximum heater ON time and O
The present invention provides a temperature control device that does not cause abnormal heating even during local heat retention in a system that performs duty control by setting the FF minimum time.

Means for Solving the Problems To solve the above problems, the temperature control device of the present invention includes a heater, an opening/closing means for controlling opening/closing of energization to the heater,
a temperature detection means for detecting the temperature of the heater; a temperature setting means for setting a control temperature of the heater; a comparison section for comparing a set voltage of the temperature setting means with a detected voltage of the temperature detection means; An ON time timer that sets the maximum ON time and an O timer that sets the minimum OFF time of the heater.
The FF time timer, the comparison section, the ON time timer, and the OF
A control unit that drives the opening/closing means based on the output of the F-time timer, and a control unit that operates the heater continuously in addition to the ON-time timer.
It consists of an ON time monitoring timer that monitors the N time.

Effect With the above configuration, when the heater 3 is turned on from the control section, the ON time timer 7 and the ON time monitoring timer 10 count. When the ON time timer 7 and the QFF time timer 8 are normal, once the ON time timer 7 counts up, the output to the heater 3 continues at FFL until at least the OFF time timer 8 counts up. However, if ON time timer 7 and OFF time timer 8 malfunction due to noise, etc., and the ON time timer 7
If it continues for NL, the ON monitoring timer 1o operates and performs abnormality processing.

Embodiment Below, a temperature control device according to an embodiment of the present invention is shown in FIGS. 1 and 2.
This will be explained using figures. FIG. 1 is a configuration diagram of the device, and FIG. 2 is a flowchart showing temperature control of the device. A comparator 6 compares the detected temperature voltage VT detected by the temperature detection circuit 6 and the set temperature voltage VR. Based on the output signal, the control unit 4 drives the relay 2 and controls the energization of the heater 3.

At this time, duty control is performed using an ON time timer 7 and an OFF time timer 8. Since these are the same as the conventional ones described above, detailed explanation thereof will be omitted.

The characteristic configuration of this embodiment is that the ON time timer 7° is OFF.
The reason is that an ON time monitoring timer 10 for monitoring the continuous ON time of the heater 3 is provided separately from the time timer 8.

The temperature control at this time will be explained using the flowchart shown in FIG. When the power switch is turned ON in step 1,
In step 2, the detected temperature voltage VT and the set temperature voltage VR are compared. If VR>VT (low temperature), the process branches to step 3, and if high temperature, the process branches to step 1o.

Now, relay 2 changes from OFF state to ON state, so
Clear each timer in step 3. In step 5, a relay ON output is performed, and in step 67, the ON time monitoring timer 10 is counted to check whether the count has increased. The count-up time of this ON-time monitoring timer 10 is larger than the timer value of the ON-time imuff, and normally does not count up. In step 89, the ON time timer 7 is counted. When the ON time timer 7 counts up or the detected temperature becomes high, steps 10 to 14 are performed when the relay is turned off. If ON time timer 7 malfunctions and the relay continues ONL, turn ON in step 6.7.
The time monitoring timer 10 counts up in the counting process, and the process moves to the relay OFF process in step 10.

Effects of the Invention As is clear from the description of the embodiments above, the temperature control device of the present invention has a simple configuration in which a timer for monitoring ON time is provided in addition to the timer for control, and the temperature control device according to the present invention has a simple structure in which a timer for monitoring ON time is provided in addition to a timer for control. - In the case of control, only the average power equivalent to the strong temperature is applied even when local heat is being kept, so there is no discoloration or burning, making it extremely safe.

In this embodiment, ON time timer 7, OFF time timer 8. Control unit 9. ON time monitoring timer IO is realized using a microcomputer, and ON time timer 7 and O
The FF time timer 8 is an independent timer, but these two timers do not need to count at the same time.
May be shared by two timers. It is clear that the temperature control is not limited to the flowchart shown in FIG. 2, and the processing when the ON time monitoring timer counts up is also not limited to the present embodiment.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a temperature control device showing an embodiment of the present invention, Fig. 2 is a flowchart showing temperature control of the same device, Fig. 3 is a block diagram of a conventional temperature control device, and Fig. 4 is the same. FIG. 6 is a diagram showing temperature control and energization states of the temperature control device in normal times and when heat dissipation is large. 2...Relay, 7...ON time timer, 8...OFF time timer, 9...Control unit, 10...ON time Monitoring timer.

Claims (1)

[Claims] a heater, an opening/closing means for controlling opening and closing of energization to the heater, a temperature detecting means for detecting the temperature of the heater, a temperature setting means for setting a control temperature of the heater, and a set voltage and temperature of the temperature setting means. a comparison section that compares the voltage detected by the detection means; and an O that sets the maximum ON time of the heater.
N time timer, an OFF time timer that sets the minimum OFF time of the heater, a control unit that drives the opening/closing means based on the outputs of the comparison unit, the ON time timer, and the OFF time timer, and separately from the ON time timer. A temperature control device comprising an ON time monitoring timer that monitors continuous ON time of the heater.