TWM588934U - Ceramic heating device - Google Patents

Abstract

A ceramic heating device includes a ceramic heating unit, a current sensing unit, a switch unit, and a control unit. The ceramic heating device controls the switch unit to be turned on by the control unit, so that the ceramic heating unit receives an operating current to generate heat; the current sensing unit detects the size of the operating current to generate an output signal; The control unit obtains the magnitude of the operating current according to the output signal, and when the control unit determines that a slope value of the operating current changes with time is less than or equal to zero, and determines that the operating current is less than a set threshold, controls the switching unit The non-conduction makes the ceramic heating unit unable to receive the operating current; and a real-time detection and protection mechanism can be realized.

Description

Ceramic heating device

The present invention relates to a heating device, especially a ceramic heating device with an overheat protection mechanism.

The ceramic heating device is a device that uses a positive temperature coefficient (Positive Temperature Coefficient, PTC) ceramic heating sheet to realize heat generation, and is widely used in equipment such as bathroom heaters and indoor electric heaters. Existing ceramic heating devices use a temperature sensor to detect the temperature of the ceramic heating sheet, for example, the temperature of its casing, so as to break the power when the device fails to ensure the safety of the user. For example, when the air duct of the bathroom heater is blocked or the motor fails, the heated heater cannot be blown out smoothly, which will cause the temperature of the ceramic heater of the heater to become higher and higher. When the temperature detected by the temperature sensor is determined by a control unit (such as a microcontroller) to exceed a critical value, the control unit sends a control signal to disconnect the ceramic heating plate and continue to receive current. Stop heating. Similarly, when the indoor electric heater is covered by clothing or cotton and the temperature rises abnormally, the same monitoring and protection mechanism is adopted. However, it is known that this method of monitoring with a temperature sensor not only indirectly detects the temperature of the housing of the ceramic heating plate, but is also often easily damaged due to frequent switching operations. Therefore, there is room for improvement in the conventional monitoring and protection mechanism of ceramic heating devices.

Therefore, the purpose of the present invention is to provide a ceramic heating device with an overheat protection mechanism.

Therefore, the present invention provides a ceramic heating device suitable for a voltage source, and includes a ceramic heating unit, a current sensing unit, a switching unit, and a control unit.

The ceramic heating unit is electrically connected to the voltage source to receive an operating current, thereby generating heat. The current sensing unit is electrically connected between the voltage source and the ceramic heating unit to detect the magnitude of the operating current received by the ceramic heating unit, thereby generating a corresponding output signal.

The switch unit is electrically connected between the voltage source and the ceramic heating unit, and includes a first end electrically connected to the voltage source, a second end electrically connected to the ceramic heating unit, and a control receiving a control signal And control whether to conduct or not conduct between the first end and the second end according to the control signal.

The control unit is electrically connected to the current sensing unit and the switching unit, and generates the control signal so that the switching unit controls the conduction between the first end and the second end, and receives the output from the current sensing unit Signal to obtain the magnitude of the operating current. When the control unit determines that a slope value of the operating current changes with time is less than or equal to zero, and determines that the operating current is less than a set threshold, the control signal is generated so that the switching unit controls the first terminal and the second terminal No conduction between.

In some embodiments, the control unit calculates the change of the operating current in the predetermined time period according to the output signal every predetermined time period to obtain the slope value.

In other embodiments, the set threshold is equal to a maximum value of the operating current multiplied by a predetermined coefficient, and the predetermined coefficient is between 0 and 1.

In some embodiments, the control unit stores the maximum value of the operating current corresponding to the ceramic heating unit in advance, or the control unit obtains the operating current according to the received output signal. The maximum value.

In other embodiments, when the control unit determines that the operating current is less than a post-opening threshold at a predetermined time after turning on, the control signal is generated so that the switching unit controls the first terminal There is no conduction between the second terminal and the threshold after the start is related to a maximum value of the operating current.

In other embodiments, the ceramic heating device further includes an alarm unit electrically connected to the control unit, and when the control unit generates the control signal so that the switch unit controls the first terminal and the second terminal When turned on, the alarm unit is controlled to issue an alarm notification, the alarm notification including at least one of a warning sound and a warning light.

The effect of the present invention lies in that the control unit controls the switch unit not to conduct when it is judged that the slope value is negative and the operation current is less than the set threshold value according to the operating current measured by the current sensing unit Stopping supplying the operating current to the ceramic heating unit can avoid permanent damage to the ceramic heating device.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same number.

Referring to FIG. 1, an embodiment of the novel ceramic heating device is suitable for a voltage source VIN, and includes a ceramic heating unit 2, a current sensing unit 3, a switching unit 4, a control unit 1, and an alarm unit 5.

The switch unit 4 includes a first terminal 41, a second terminal 42 electrically connected to the switch unit 4, and a control terminal 43 electrically connected to the control unit 1 to receive a control signal, and according to the control signal, for example according to The voltage value or logic value of the control signal controls whether the first terminal 41 and the second terminal 42 are conductive or non-conductive. The switch unit 4 is, for example, a relay, but it is not limited to this.

The ceramic heating unit 2 is electrically connected to the voltage source VIN and the switch unit 4, and when the first terminal 41 and the second terminal 42 of the switch unit 4 are conducted, receiving an operating current from the voltage source VIN, Then get fever. The ceramic heating unit 2 includes at least one ceramic heating plate. When the operating current flows through the at least one ceramic heating plate, the at least one ceramic heating plate generates heat and causes a temperature rise. Referring again to FIG. 2, FIG. 2 exemplarily depicts the correspondence between the operating current and the temperature of the ceramic heating unit 2.

The current sensing unit 3 is electrically connected between the voltage source VIN and the first end 41 of the switching unit 4 to detect the magnitude of the operating current received by the ceramic heating unit 2 to generate a corresponding output signal. For example, the current sensing unit 3 converts the detected operating current into a voltage value of the output signal, but not limited to this.

The alarm unit 5 is electrically connected to the control unit 1 and is controlled to issue an alarm notification. The alarm notification includes a warning sound or a warning light, or the warning sound or the warning light. The alarm unit 5 is, for example, a buzzer and a light-emitting element.

The control unit 1 is electrically connected to the current sensing unit 3 and the control terminal 43 of the switch unit 4 and generates the control signal so that the switch unit 4 controls the conduction between the first terminal 41 and the second terminal 42, And receive the output signal from the current sensing unit 3 to obtain the magnitude of the operating current. More specifically, the control unit 1 records or stores the magnitude of the operating current according to the output signal every predetermined period of time. The predetermined period of time is, for example, 1 second, or other lengths of time, such as less than 10 seconds Within, but not limited to.

When the control unit 1 determines that the magnitude of the operating current is less than a threshold after opening a predetermined time after opening, the control signal is generated to enable the switching unit 4 to control between the first terminal 41 and the second terminal 42 Not conductive. The predetermined time after the start is 10 seconds, for example. The threshold value after starting is related to a maximum value of the magnitude of the operating current. The threshold value after starting is, for example, 25% of the maximum value. In other words, the control unit 1 determines whether the ceramic heating device has abnormality by judging the magnitude of the operating current at the 10th second after the ceramic heating device is turned on, and controls the The switch unit 4 is not turned on, so that the ceramic heating unit 2 no longer receives the operating current and stops heating, and the alarm unit 5 is controlled to issue the alarm notification to warn the surrounding users that the ceramic heating device has abnormality.

When the control unit 1 determines that a slope value of the operating current changes with time is less than or equal to zero, and determines that the operating current is less than a set threshold, the control signal is generated so that the switching unit 4 controls the first terminal 41 and the There is no conduction between the second ends 42. According to the previous example, the control unit 1 calculates the slope value every 1 second. For example, if the operating current in the first, second, and third seconds is 1450mA, 1500mA, and 1300mA, then the slope value The calculation results at the second and third seconds are 50 mA/sec and -200 mA/sec, and the slope value at the third second is less than or equal to zero. The set threshold is equal to a maximum value of the magnitude of the operating current multiplied by a predetermined coefficient. The predetermined coefficient is between 0~1, preferably, it can be selected between 0.6~0.7.

In this embodiment, the control unit 1 pre-stores the maximum value of the magnitude of the operating current. Referring again to FIG. 2, the maximum value is 1500 mA, the predetermined coefficient is 0.7, for example, and the set threshold is 1050 mA. In the process of heating up after the ceramic heating unit 2 is turned on, the temperature rises from room temperature to a set temperature (the set temperature is less than or equal to 200 degrees). At this time, the corresponding operating current is less than the maximum value (that is, 1500 mA). When the ceramic heating device is abnormal, the temperature of the ceramic heating unit 2 continues to rise from 200 degrees to 225 degrees, for example, the slope value is negative and the operating current (ie 850mA) is less than the set threshold (ie 1050mA ), the control unit 1 controls the switch unit 4 to be non-conducting, so that the ceramic heating unit 2 no longer receives the operating current and stops heating, and controls the alarm unit 5 to issue the alarm notification to warn the surrounding users, the An abnormality has occurred in the ceramic heating device.

In other embodiments, the control unit 1 may also obtain the maximum value of the operating current according to the received output signal. For example, according to the output signal, the control unit 1 updates the maximum value of the operating current at any time, and then refer to FIG. 2, during the heating process of the ceramic heating unit 2 after turning on, for example, from room temperature to Between 200 degrees, at this time, the control unit 1 can update the maximum value as the obtained operating current gradually becomes larger. On the other hand, when the ceramic heating device is abnormal, the temperature of the ceramic heating unit 2 continues to rise from 200 degrees to 225 degrees. At this time, the corresponding operating current also decreases from 1500mA to 850mA. However, the maximum The value is still maintained at the maximum value (ie) 1500mA, and the set threshold is maintained at 1050mA.

In addition, it should be particularly added that in this embodiment, the operating current is not limited to DC current or AC current, and can be implemented accordingly. Furthermore, in other embodiments, the current sensing unit 3 and the switching unit 4 may also be electrically connected at different positions, as long as the current sensing unit 3 is electrically connected to the voltage source VIN and the ceramic heating unit 2 The size of the operating current can be detected occasionally, and the switch unit 4 is electrically connected between the voltage source VIN and the ceramic heating unit 2 to control whether the ceramic heating unit 2 receives or does not receive the operating current.

Referring to FIGS. 1 and 2, FIG. 2 exemplarily illustrates a flowchart of a control method implemented by the novel ceramic heating device. The control method includes steps S1 to S3.

In step S1, the control unit 1 determines whether the ceramic heating device is turned on, such as when the user turns on or off, that is, when the control unit 1 judges that it is turned on, the control unit 1 controls the switch unit 4 to turn on, so that the The ceramic heating unit 2 receives the operating current and generates heat. Next, step S2 is executed. Conversely, when the control unit 1 determines that it is not turned on, it returns to the starting position.

In step S2, the current sensing unit 3 detects the magnitude of the operating current to generate the corresponding output signal.

In step S3, the control unit 1 obtains the magnitude of the operating current according to the output signal. When the control unit 1 determines that the slope value of the operating current changes with time is less than or equal to zero, and determines that the operating current is less than the setting At the threshold, the switching unit 4 is controlled not to conduct, so that the ceramic heating unit 2 cannot receive the operating current. In more detail, step S3 includes sub-steps S30 to S34.

In sub-step S30, when the control unit 1 determines that the operating current is smaller than the post-opening threshold within a predetermined time after the start, step S34 is executed.

In step S31, the control unit 1 calculates the change of the operating current in the predetermined time period according to the output signal every predetermined time period to obtain the slope value.

In step S32, the control unit 1 determines whether the slope value of the operating current changes with time is less than or equal to zero. When it is judged to be less than or equal to zero, sub-step S33 is performed, and when it is judged to be greater than zero, it returns to sub-step S2.

In step S33, the control unit 1 determines whether the operating current is less than the set threshold. When it is judged to be less than the set threshold, sub-step S34 is executed, and when it is judged to be greater than or equal to the set threshold, return to sub-step S2.

In step S34, the control of the switch unit 4 is not conducted, so that the ceramic heating unit 2 cannot receive the operating current, and the alarm unit 5 is controlled to issue the alarm notification.

In summary, the present invention does not require a conventional temperature sensor to detect the temperature of the ceramic heating unit, but uses the physical characteristics of the ceramic heating sheet itself, for example, the bathroom heater is blocked by the air duct or the motor malfunctions, or Indoor heaters are covered by clothing or cotton quilts, so that after the temperature of the ceramic heating sheet exceeds its physical temperature, the current consumed will drop sharply. Therefore, the control unit judges that the slope value is negative and the operating current is less than the set threshold by the operating current measured by the current sensing unit, and controls the switching unit to stop providing the operating current to the ceramic The heating unit avoids permanent damage to the ceramic heating device, and also controls the alarm unit to issue a warning, so it can indeed achieve the purpose of a new type of cost.

However, the above are only examples of the new model. When the scope of the new model cannot be limited by this, all simple equivalent changes and modifications made according to the patent application scope and patent specification content of the new model are still classified as Within the scope of this new patent.

1‧‧‧Control unit 2‧‧‧Ceramic heating unit 3‧‧‧Current sensing unit 4‧‧‧Switch unit 5‧‧‧Alarm unit 41‧‧‧First 42‧‧‧The second end 43‧‧‧Control VIN‧‧‧Voltage source S1~S3‧‧‧Step S30~S34‧‧‧Substep

Other features and functions of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: FIG. 1 is a block diagram illustrating an embodiment of the novel ceramic heating device; 2 is a graph illustrating the correspondence between the operating current and temperature of a ceramic heating unit of this embodiment; and FIG. 3 is a flowchart illustrating the control method implemented by this embodiment.

1‧‧‧Control unit

2‧‧‧Ceramic heating unit

3‧‧‧Current sensing unit

4‧‧‧Switch unit

41‧‧‧First

42‧‧‧The second end

43‧‧‧Control

5‧‧‧Alarm unit

VIN‧‧‧Voltage source

Claims (6)

A ceramic heating device, suitable for a voltage source, and contains: A ceramic heating unit, electrically connected to the voltage source, to receive an operating current, and then generate heat; A current sensing unit is electrically connected between the voltage source and the ceramic heating unit to detect the magnitude of the operating current received by the ceramic heating unit, thereby generating a corresponding output signal; A switch unit is electrically connected between the voltage source and the ceramic heating unit, and includes a first end electrically connected to the voltage source, a second end electrically connected to the ceramic heating unit, and a receiver receiving a control signal A control terminal, and controlling the conduction or non-conduction between the first terminal and the second terminal according to the control signal; and A control unit electrically connecting the current sensing unit and the switching unit, and generating the control signal so that the switching unit controls the conduction between the first end and the second end, and receives the current from the current sensing unit Output a signal to obtain the magnitude of the operating current, when the control unit determines that a slope value of the operating current changes with time is less than or equal to zero, and determines that the operating current is less than a set threshold, the control signal is generated to cause the switch The unit controls the non-conduction between the first end and the second end. The ceramic heating device according to claim 1, wherein the control unit calculates the change of the operating current in the predetermined time period according to the output signal every predetermined time period to obtain the slope value. The ceramic heating device according to claim 1, wherein the set threshold is equal to a maximum value of the magnitude of the operating current multiplied by a predetermined coefficient, and the predetermined coefficient is between 0~1. The ceramic heating device of claim 3, wherein the control unit stores the maximum value of the operating current corresponding to the ceramic heating unit in advance, or the control unit obtains the operation according to the received output signal This maximum value of the magnitude of the current. The ceramic heating device according to claim 1, wherein when the control unit determines that the operating current is smaller than a post-opening threshold at a predetermined time after turning on, the control signal is generated so that the switching unit controls the There is no conduction between the first end and the second end, and the threshold after the activation is related to a maximum value of the operating current. The ceramic heating device according to claim 1, further comprising an alarm unit electrically connected to the control unit, when the control unit generates the control signal so that the switch unit controls the non-conduction between the first end and the second end At this time, the alarm unit is controlled to issue an alarm notification, the alarm notification including at least one of a warning sound and a warning light.

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