An electric heating appliance with conveniently adjustable temperature

Abstract

The application discloses an electric heating appliance with adjustable temperature, which comprises a heating carrier, a heating element, an interface fixed box, a connecting flexible wire, a controller and a plug wire. The heating element is installed on the heating carrier. An interface fixed box at one end of the heating carrier is connected with the controller through the connecting flexible wire, and is connected with a power supply through a power supply plug. The controller comprises a shell and a control circuit installed in the shell. The application has the advantages of adjustable temperature, less interface joints, less components, high safety, low failure rate, no electromagnetic pollution, high cost performance, easy scale production and the like. The application can be used for adjusting other physical quantities of electric appliances, such as the speed of an electric fan, the light of various lamps and the like.

Description

Technical Field

[0001] This invention relates to the field of household electric heating appliances, and in particular to an electric heating appliance with easily adjustable temperature. Background Technology

[0002] Currently, there are three types of temperature-regulating electric blankets: 1. Using the unidirectional conductivity of diodes to reduce the power of the appliance from full power to half power, thereby regulating the temperature of the electric blanket; 2. Regulating the temperature of the electric blanket by changing the conduction angle of a 220V~50Hz sine wave voltage; 3. Adjusting the frequency of the 220V~50Hz sine wave voltage, that is, adjusting the number of 50Hz sine wave voltages per second (or the duty cycle) to reduce the power and regulate the temperature of the electric blanket.

[0003] None of the three temperature regulation methods described above have a temperature limiting function. To prevent fires, the heating element must have a double-layer spiral structure and cannot be folded; otherwise, the product will be unusable. Except for the third method, which has an automatic control function, the other two lack automatic switching capabilities. A common drawback of these three methods is:

[0004] 1. The load (heating wire) is always powered on and heating. If there is poor contact at the interface or a broken wire in the heating wire, arcing (commonly known as sparking) can easily occur, causing the electric blanket to be scrapped or causing a fire.

[0005] 2. The above three products can only use AC power, not DC power;

[0006] 3. The first type only has two temperature selection levels (high and low), which is difficult to meet the usage requirements; the second type uses phase shifting, which changes the waveform of the 220V~50Hz sine wave voltage, thus generating harmonic interference; the third type has a different starting heating power than the set heating power, which means that the heating power must change when automatically switching levels, making it difficult to determine the rated power of the appliance. The first two types can only be designed for products with relatively small heating power and slow heating, otherwise it is easy to cause fire accidents.

[0007] In addition, the above three methods of temperature adjustment are difficult to use on electric heating pads, let alone on small electric heating appliances, and especially not on DC electric heating appliances.

[0008] To address this issue, we propose an electric heating appliance with easily adjustable temperature. Summary of the Invention

[0009] The purpose of this invention is to provide an electric heating appliance with easily adjustable temperature. The temperature is adjustable and limitable, and the product has the characteristics of fewer interface contacts, fewer components, high safety, low failure rate, no electromagnetic pollution, high cost performance, and easy mass production. In addition to electric heating appliances, this invention can also be used to adjust the physical quantities of other electrical appliances, such as speed control of electric fans and dimming of various lamps.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] An electrically heated appliance with easily adjustable temperature comprises a heating carrier, a heating element, an interface fixing box, a connecting cord, a controller, and a power plug. The heating element is mounted on the heating carrier. The interface fixing box, located at one end of the heating carrier, is connected to the controller via the connecting cord and the power plug. The controller includes a housing and a control circuit installed within it. The control circuit includes a power supply that provides operating voltage to a microcontroller and its associated operating, display, and auxiliary circuits. The microcontroller outputs a periodic high- and low-level signal to control the conduction or cutoff of the actuator, forming a temperature regulation circuit and a temperature limiting circuit.

[0012] The temperature regulation circuit is composed of the microcontroller's operation circuit port c, the display circuit port d, the output port a, and the output circuit resistor R0 to the actuator.

[0013] The temperature limiting circuit consists of a microcontroller port b receiving high and low voltage levels from the temperature limiting resistor R, which is then processed to control the output state of the microcontroller's output port.

[0014] In a further embodiment, in the temperature regulation circuit, the microcontroller output port a outputs one or more cycle levels.

[0015] In a further embodiment, in the temperature limiting circuit, the microcontroller's high and low level receiving port processes the received limiting level and the high-low conversion level within the microcontroller to change the output state of the output port, and controls the conduction and cutoff of the actuator through resistor R0.

[0016] In a further embodiment, the port through which the microcontroller accepts high and low levels is one or more output ports.

[0017] In a further embodiment, the output port a of the microcontroller is one output port or one of two or more output ports.

[0018] In a further embodiment, the actuator mainly consists of a silicon controlled rectifier (SCR), a field-effect transistor (FET), a switching transistor, and a relay.

[0019] In a further embodiment, the microcontroller's operating voltage is equipped with a fine-tuning voltage circuit to adjust the level of the operating voltage. In conjunction with the pulse voltage change on the temperature-limiting resistor R, the pulse voltage change is received by any port of the microcontroller and processed internally before being output to the output port as a low-level signal or a high-level signal to control the cutoff or conduction of the actuator.

[0020] In a further embodiment, the power source can be one of AC, DC, or a mobile power source.

[0021] In a further embodiment, the heating element is composed of a single heating wire or heating plate, and its structure is one of a single spiral, straight wire, carbon fiber wire, carbon film, or graphene film.

[0022] In a further embodiment, the interface fixing box has two single-control interface contacts and three dual-control interface contacts.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention features adjustable and limitable temperature, and the product boasts advantages such as fewer interface contacts, fewer components, high safety, low failure rate, no electromagnetic pollution, high cost-effectiveness, and ease of mass production. Besides electric heating appliances, this invention can also be used to regulate other electrical physical quantities, such as speed control of electric fans and dimming of various lamps.

[0025] 1. Since the temperature range of each gear adopts the ratio of electrical energy consumed per unit time, that is, only the period (tax+tbx) (hereinafter referred to as output period) and cycle time ti of the microcontroller output port are changed to control the conduction and cutoff of the actuator, and the voltage, frequency and heating power of the power supply used by this appliance do not change, it is very convenient to design and manufacture appliances with adjustable temperature using various power supplies (including low voltage power supply and mobile power supply, etc.).

[0026] 2. Since the temperature range of each gear uses the ratio of electrical energy consumed per unit time, that is, only changing the output cycle and cycle time ti of the microcontroller output port to control the on and off working mode of the actuator, it is very convenient to manufacture temperature-adjustable single-control, dual-control and multi-channel control electric blankets, mats and similar heating appliances.

[0027] 3. Since the temperature range of each gear adopts the ratio of electrical energy consumed per unit time, that is: only the output cycle and cycle time ti of the microcontroller output port are changed to control the on and off working mode of the actuator. It can also be used to adjust other electrical physical quantities, such as the speed control of electric fans, the dimming of various lamps, etc.

[0028] 4. Since the temperature range of each gear adopts the ratio of electrical energy consumed per unit time, that is, only the output cycle and cycle time ti of the microcontroller output port are changed to control the conduction and cutoff of the actuator, it has the characteristics of fewer interface contacts (two contacts), fewer components, small size and high reliability.

[0029] 5. Because any port (or n ports) of a single-chip microcomputer (MCU) can accept the voltage level (low level or pulse level, determined by the temperature coefficient of the load heating material) on a temperature-limiting resistor R (or multiple resistors) connected in series with the load, the voltage level on the temperature-limiting resistor is processed to control the periodic change of the high and low voltage levels of the corresponding output port (or n ports), and the temperature control method of controlling the conduction or cutoff of the actuator (or multiple actuators) through the output circuit makes the temperature of the appliance controllable and adjustable;

[0030] 6. Because the microcontroller uses any port (or n ports) to accept the temperature limiting level (high level, low level, or pulse level, determined by the positive temperature coefficient of the load's heating material) on the temperature limiting resistor R (which can be multiple) connected in series with the load, and processes it to control the periodic change of the high and low level output of the corresponding output port (which can also be n ports), and controls the conduction or cutoff of the actuator (which can correspond to multiple actuators) through the output circuit, it is very convenient to manufacture various appliances with controllable and adjustable temperature.

[0031] 7. Due to the adoption of an adjustable power supply circuit for the control circuit, various appliances can easily implement temperature limiting functions. Attached Figure Description

[0032] Figure 1 This is a diagram showing the composition of an electric heating appliance for which the temperature can be easily adjusted in this device.

[0033] Figure 2 This is a block diagram of the controller components of this device;

[0034] Figure 3 A schematic diagram of the device for single-control half-wave three-level temperature regulation of LED displays;

[0035] Figure 4 A schematic diagram of the device for single-control full-wave three-level temperature regulation of LED displays;

[0036] Figure 5 A schematic diagram of the structure of this device for dual-control half-wave four-level temperature regulation of LED displays;

[0037] Figure 6 This is a schematic diagram of the structure of the device for dual-control full-wave temperature regulation with digital tube display of gear position.

[0038] In the diagram: 1. Heating carrier; 2. Heating element; 3. Interface fixing box; 4. Connecting cord; 5. Controller; 6. Plug wire. Detailed Implementation

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Please see Figure 1-6 An electric heating appliance with easily adjustable temperature is composed of a heating carrier 1, a heating element 2, an interface fixing box 3, a connecting cord 4, a controller 5, and a power plug 6. The heating element 2 is installed on the heating carrier 1. The interface fixing box 3, which is the power input at one end of the heating carrier 1, is connected to the controller 5 via the connecting cord 4 and connected to the power supply via the power plug (or connector) 6.

[0043] See Figure 2The block diagram of controller 5 of this device (excluding the plug wire connecting the power supply and the load connection cord, the rest of the blocks are hereinafter referred to as controller 5), includes the housing and the control circuit installed therein. The control circuit includes a power supply, which is applied to the microcontroller. The temperature regulation circuit of the appliance is composed of the microcontroller's operation circuit port c, display circuit port d, output port a, and output circuit resistor R0 to the actuator. In the temperature regulation circuit, the microcontroller output port a (which can be one output port, or two or more output ports) outputs one or more cycle levels (see the temperature regulation description below). In the block diagram of the temperature regulation circuit, if the microcontroller is added... The port b, which receives high and low voltage levels, receives pulse levels on the temperature-limiting resistor R (due to the change in the resistance value of the heating wire with a positive temperature coefficient in the load RL). After technical processing, this pulse level is used to control the output state of the microcontroller's output port, thus forming a temperature-limiting circuit. In this circuit, the microcontroller's high and low voltage receiving ports (one or more ports) process the received limiting voltage level with the high-low conversion level within the microcontroller (see the explanation of "Temperature Limiting Principle" below) to change the output state of the output port. Through resistor R0, the actuator (thyristor, MOSFET, switching transistor, relay, etc.) is controlled to turn on and off (not turn on), thereby allowing the load to be heated or not heated to achieve the function of regulating and limiting the temperature.

[0044] In the temperature regulation circuit, the controller uses a microcontroller to adjust the temperature based on the ratio (magnitude) of electrical energy consumed per unit time at each temperature setting.

[0045] In the temperature limiting circuit, the controller uses a method where the changing pulse level on the temperature-limiting resistor R is received by the microcontroller and the output cycle level of the control output port a achieves the temperature limiting function. Its temperature limiting function works best when used in conjunction with the temperature regulation circuit.

[0046] Temperature regulation principle: see Figure 2 The circuit consisting of the temperature limiting resistor R with a value of zero (the temperature limiting resistor R is short-circuited and the microcontroller receiving port b is not used) is a temperature regulation circuit. The temperature regulation of this device adopts a stepped multi-level, and each level corresponds to a temperature range.

[0047] In electric blanket products (hereinafter referred to as appliances), for appliances with constant power P and operating voltage U, under the same ambient temperature and insulation conditions, a longer working time results in a higher surface temperature, and a shorter working time results in a lower surface temperature. Based on this working state, the temperature regulation of this device is achieved by changing the ratio of electrical energy consumed by the appliance per unit working time (heating time and non-heating time for each corresponding setting), thus achieving the function of temperature regulation. The principle analysis is as follows:

[0048] If the power supply used by this device is U, the heating power is P, and the controller has x operating levels (temperature ranges) (x can be 1 to 10, or more levels can be used), the heating time for each of the x levels is denoted as tax, and the non-heating time is denoted as tbx. Let (tax + tbx) be the working cycle of level x, and the cycle time of (tax + tbx) be denoted as ti. Then the average power of each cycle is: P × tax / (tax + tbx). According to the energy formula: W = P × t, the electrical energy consumed by this appliance at level x during the cycle time ti is:

[0049] Wx=P×tax / (tax+tbx)×ti……(1)

[0050] Equation (1) above shows that, under the condition that the power P remains unchanged, by changing the working cycle (txa+txb) and cycle time ti of the x-level of the controller, the electrical energy consumed by the x-level of this device can be easily changed, thereby conveniently adjusting the temperature of the x-level of the controller. The temperature adjustment of other levels is the same.

[0051] According to Ohm's law, P = U² / R, where R is the load resistance of the device and U is the operating voltage of the appliance. Substituting P = U² / R into equation (1), we get:

[0052] Wx=U² / R×tax / (tax+tbx) ×ti……(2)

[0053] Equation (2) above shows that, under the condition that the working voltage U remains unchanged, by changing the working cycle (tax+tbx) and cycle time ti of the controller x-level, the electrical energy consumed by the x-level of this appliance can be easily changed, thereby conveniently adjusting the temperature of the x-level of this appliance.

[0054] Explanation of letters and symbols in equations (1) and (2) above:

[0055] Wx: The electrical energy consumed by this device at the "x" setting (which can be one or more combined sets), and the same applies to other settings. If "x" is 1, it means that this device has only one setting (one temperature range); if "x" is 3, it means that this device has three settings (three temperature ranges), namely setting one, setting two, setting three, and so on.

[0056] P: Power of this appliance (In the temperature regulation circuit, P is not related to the temperature coefficient of the heating element; in the temperature control circuit, P is related to the temperature coefficient of the heating element).

[0057] U: The voltage of the power supply used by this device (U is a constant during operation);

[0058] R: Load resistance of this appliance (heating material with a temperature coefficient must be used in the temperature control circuit).

[0059] (tax+tbx): The working cycle of the controller in the "x" position of this device can be a combination of one or more cycles, where: tax corresponds to the heating time of this appliance in the x position (unit: seconds), and can be any number where tax > 0 as needed; tbx corresponds to the non-heating time of the controller in the x position (unit: seconds), and can be any number where tbx ≥ 0 as needed (when tbx is zero, it means that this appliance heats at power P). For example, there are two cycles of (ta1x+tb1x) and (ta2x+tb2x), which are expressed as {(ta1x+tb1x)+(ta2x+tb2x)}, and so on;

[0060] tax / (tax+tbx): The average power factor of this device (can be one or more), with a maximum value of 1 for each; it can also be referred to as the duty cycle of this appliance. For example: the above expression for a two-cycle operation is {(ta1x+tb1x)+(ta2x+tb2x)}, then the average power factor is {(ta1x+ta2x) / (ta1x+tb1x+ta2x+tb2x)}, and so on;

[0061] Ti: The time (in minutes or hours) for the device to cycle through (tax + tbx) at the x-gear setting. The unit should be consistent when calculating energy consumption. The same logic applies to other gears. The cycle time ti can be the sum of the cycle times for multiple cycles. For example, if the cycle time for the first cycle (ta1x + tb1x) is ti1, and the cycle time for the second cycle (ta2x + tb2x) is ti2, then the total energy consumed at the x-gear setting is: P × {ta1x / (ta1x + tb1x) × ti1 + ta2x / (ta2x + tb2x) × ti2}. The same logic applies to other cycles.

[0062] In equations (1) and (2) above, the heating time tax, non-heating time tbx, and cycle time ti of the device in the x-level working cycle (tax+tbx) can be designed for n cycles and multiple corresponding cycle times. Figure 1 The output port of the microcontroller in the program is completed by the program. Equations (1) and (2) above are a group description of the output port of the microcontroller to the actuator. Similarly, there can be two or more groups of temperature regulation. Since the output port outputs a periodic level or a high or low level, this control method can be used for the physical quantity regulation and control of other electrical appliances.

[0063] To prevent the appliance temperature from rising during use, simply run the highest temperature setting until the temperature does not become dangerous, at which point the microcontroller will cut off the appliance's power supply or switch it to a low-power setting. It can also be used in conjunction with the temperature limiting function described below. The specific implementation method will not be explained here.

[0064] Temperature limiting principle: (Note: Temperature limiting refers to preventing the device from generating temperatures that pose a danger to the environment and user when it is not operating normally (such as folding), or limiting the device to a certain set temperature below the set temperature), see [link to relevant documentation]. Figure 2 The microcontroller (MCU) in the block diagram has ports that output or receive high and low levels. The operation and display circuits are composed of n output ports of the MCU, which select and display temperature ranges. Output port a (which can be one or n) of the MCU in the block diagram outputs a periodic high and low level (programmed). Port b (which can be one or more, three in Examples 1 and 2) receives the pulse level from the temperature-limiting resistor R and controls the periodicity of the corresponding output port's high and low level output or maintains the original output state (programmed). The temperature limiting principle is as follows: Port b (which can be multiple) of the MCU in the block diagram receives the pulse level or low level (generated by the resistance change of the heating material with a positive temperature coefficient) from the temperature-limiting resistor R (which can be several resistors connected in series). This pulse level or low level is processed to control the output periodicity of output port a (which can be multiple), which in turn controls the conduction or cutoff of the actuator via output resistor R0, thus heating or de-heating the load, thereby achieving the temperature limiting function. Note: The temperature limiting function works best when used in conjunction with the temperature regulation function described above.

[0065] The temperature regulation and temperature limitation of this device are based on the fact that the output ports of the microcontroller are all periodic levels consisting of high and low levels. The output circuit drives the actuator to turn on or off, that is, the two operating states of full power heating and heating stop. Therefore, this switch-type control method of the device can also be called analog temperature control.

[0066] In summary, the temperature regulation and temperature limiting functions of this device can be used independently or in combination. Since the power supply voltage and heating power remain unchanged during use, and the temperature limiting circuit for obtaining temperature changes is simple and reliable, mass production of this device is possible.

[0067] Example 1

[0068] See Figure 3 For electric blankets with temperature settings of three or lower, or higher, you only need to reduce or add indicator lights and modify the program accordingly.

[0069] Circuit connection instructions: Connect the AC power to terminals ax and bx. Terminal ax is divided into two paths. One path connects to the step-down resistor R1, diode D1, Zener diodes DW and D2, filter capacitor C1, anti-interference capacitor C2, and terminal bx. The common connection point of the negative terminals of D1 and DW, and C1 and C2, is connected to pin 4 (positive power supply) of the MCU. Pin 11 (ground) of the MCU is connected to terminal bx. The other path connects to one end of the load RL, and the other end of RL connects to the positive terminal of the SCR V. The negative terminal of the SCR V connects to the temperature-limiting resistor R5, one end of resistor R4, and pin 2 (BH1) of the MCU. The other end of R5 connects to one end of the series temperature-limiting resistor R6 and pin 14 (BH2) of the MCU. The other end of R6 connects to the series temperature-limiting resistor R7. One end of R7 is connected to pin 13 (BH3) of the MCU, and the other end of R7 is connected to the power supply bx terminal; the other end of R4 is connected to the trigger terminal of the thyristor V and one end of the output resistor R3, and the other end of R3 is connected to pin 1 (OUT1) of the MCU; pins 8, 9, and 10 of the MCU are connected to the negative terminals of indicator lights LED1, LED2, and LED3 respectively, and the positive terminals of the three indicator lights are connected to one end of resistor R8, and the other end of R8 is connected to the bx terminal; one end of AN1 and AN2 is connected to pins 6 (KEY1) and 7 (KEY2) of the MCU respectively, and the other end of AN1 and AN2 is connected to the bx terminal; pin 3 (OUT2) of the MCU is connected to one end of resistor R2, and the other end of R2 is connected to the positive terminals of DW and D2.

[0070] The following is combined Figure 2 The explanation is as follows: Figure 3The connections of R1, diode D1, Zener diodes DW and D2, filter capacitor C1, and anti-interference capacitor C2 form the power supply for the control circuit (a resistor-based step-down circuit for easy surface mount manufacturing) and provide power to the microcontroller (MCU). Pins 8, 9, and 10 of the MCU are connected to the negative terminals of indicator lights LED1, LED2, and LED3, respectively. The positive terminals of LED1, LED2, and LED3 are connected to the positive terminal of the control power supply through resistor R8, forming three gear display circuits corresponding to gear "1", "2", and "3". The connections of pins 6 (KEY1) and 7 (KEY2) of the MCU with AN1 and AN2 form the operation circuit. Button AN1 is the power switch (this circuit uses pin 6 of the MCU to receive pulse signals to control the output port to output a low or high level, or the corresponding periodic level for each gear, which in turn causes the unidirectional thyristor to be cut off or turned on through the output circuit). Button AN2 is the gear selection button. Pin 7 (KEY2) receives a pulse signal to cyclically select "1", "2", and "3" gear levels, with corresponding indicator lights LED1, LED2, and LED3 lighting up; otherwise, they remain off. Pins 2 (BH1), 14 (BH2), and 13 (BH3) of the MCU are high and low level receiving ports, respectively receiving the temperature-limiting resistors (R5+R6+R7), (R6+R7), and R7. The change in operating current caused by the temperature change of the load RL controls the level change of the corresponding temperature-limiting resistor. This changes are processed to control the output state of pin 1 (OUT1) of the MCU, and through resistor R3, control the conduction and cutoff of the actuator, thus heating or de-heating the load RL to achieve temperature regulation and temperature limiting functions. The connection between pin 3 (OUT2) of the MCU, resistor R2, Zener diode DW, and diode D2 forms the voltage fine-tuning circuit of the MCU's operating power supply, improving the reliable operation of the temperature limiting circuit. Figure 3 The connection relationship between the temperature limiting resistor and the receiving port in the "1", "2", and "3" ranges is determined by the temperature coefficient of the heating material of the load RL. The temperature of "1" is the lowest, the temperature of "3" is the highest, and the temperature of "2" is in between.

[0071] The instructions for using temperature control at level "3" are as follows: Figure 3The heating time for setting "3" is ta33 (ta33 represents ta - heating time, 33 - a total of 3 settings, corresponding to setting 3), and the non-heating time is tb33 (tb33 represents tb - non-heating time, 33 - a total of 3 settings, corresponding to setting 3). Powering on the MCU by pressing the power button AN1 puts all ports into normal operation. Pressing the operation button AN2 to select setting "3" illuminates the corresponding indicator LED3. The temperature control sampling circuit consists of pin 13 (BH3) of the MCU and the temperature-limiting resistor R5. Pin 1 (OUT1) of the MCU outputs a high / low level with a cycle of (ta33 + tb33), which, through resistor R3, controls the conduction and cutoff of the thyristor V, causing the load RL to cycle through a period of heating for ta33 seconds and not heating for tb33 seconds. In this cycle, if pin 13 (BH3) of the MCU receives a level from the temperature limiting resistor R5, then pin 1 (OUT1) maintains the output cycle (ta33+tb33). In this cycle, if pin 13 (BH3) receives a low level from R5, then pin 1 (OUT1) changes from the output cycle (ta33+tb33) to output a low level or a certain cycle. While pin 1 (OUT1) is outputting a low level or running a certain cycle, if pin 13 receives a temperature limiting level from R5, then pin 1 (OUT1) returns to the original cycle (ta33+tb33), and so on. In this way, the "3" setting achieves the limitation of the set temperature.

[0072] The temperature limits for "2" and "1" are only different in terms of operating cycle, receiving level port, and temperature limiting resistor. The heating time relationship for the three levels is: ta33 > ta23 > ta13, and the non-heating time relationship is: tb33 ≤ tb23 ≤ tb13. The operating principle is the same as above and will not be described again.

[0073] Figure 3 If the high and low level receiving ports of pins 2 (BH1), 14 (BH2), and 13 (BH3) of the MCU and the corresponding temperature limiting resistors are short-circuited (not used), and pin 3 (OUT2) of the MCU and resistor R2 are not used, then a temperature regulation circuit is formed. The operation of each level is controlled by the corresponding cycle output of pin 1 (OUT1) of the MCU to control the conduction and cutoff of the thyristor, so that the load RL is heated or not heated to achieve the function of temperature regulation.

[0074] superior Figure 3 This takes into account the requirement that the main control circuit board of this device is manufactured using surface mount technology.

[0075] Down Figure 5 This is Embodiment 3 of the device, which is composed of two sets of single-controllers combined, each set being connected to the above... Figure 3The principle is the same, except that it adds a four-speed setting and a timer selection button, and the timer has three additional time options. Its operating principle is the same as above. Figure 3 The circuit will not be described here. The heating time relationship for temperature control settings "4", "3", "2", and "1" is: ta44 > ta34 > ta24 > ta14, and the non-heating time relationship is: tb44 ≤ tb34 ≤ tb24 ≤ tb14.

[0076] The circuit also takes into account the requirement that the main control circuit board for the control switch be manufactured using surface mount technology.

[0077] Example 2

[0078] See Figure 4 , combined Figure 1 Circuit diagram connection instructions: Figure 4 The trigger component ε works with V1 to provide the trigger voltage for V2 and forms a full-wave operating circuit with V1. Other parts are connected to... Figure 3 —LED display, single-control, half-wave, three-level temperature control. The temperature control circuit of this appliance has the same function, so it will not be described again here.

[0079] Figure 4 Except for the mains power supply being connected to pin 2 of component ε, pin 1 of trigger component ε being connected to the positive terminal of V1; the negative terminal of V2 being connected to the positive terminal of V1, the trigger terminal of V2 being connected to pin 3 of trigger component ε, and the positive terminal of V2 being connected to the bx terminal, component ε P, in conjunction with V1, provides the trigger voltage for V2, so that V2 and V1 form a full-wave control circuit, and the rest are the same. Figure 3 —LED display, single control, half-wave, three-level temperature adjustment. This appliance has the same functions and will not be described again.

[0080] Example 3

[0081] See Figure 6 , combined Figure 1Connection instructions: Connect the AC power to terminals ax and bx. Terminal ax is divided into two paths. One path connects capacitor C1, resistors R1 and R2, diodes D1 and D2, Zener diode DW, filter capacitor C2, anti-interference capacitor C3, and terminal bx. The common connection of DW, C2, and C3 is connected to pin 4 (positive power) of the MCU, and pin 11 (ground) of the MCU is connected to terminal bx. The other path connects to one end of the load RL, and the other end of RL is connected to the positive terminal of the SCR V. The negative terminal of SCR V is connected to the positive terminal of diode D3 and the negative terminal of diode D4. The negative terminal of D3 is connected to pin 7 (BH1) of the MCU and the limit... The temperature-controlled resistor R4 is connected to the positive terminal of D4 and is also connected to the bx terminal. The trigger terminal of the thyristor V is connected to one end of the output resistor R3, and the other end of R3 is connected to pin 1 (OUT1) of the MCU. Pins 8, 9, 10, 12, 13, and 14 of the MCU are connected to the pins of the digital tube display C, B, AD, E, G, and F respectively. The COM pin of the digital tube is connected to the VCC corresponding to the operation of the control circuit through resistor R5. One end of AN1 and AN2 is connected to pins 6 (KEY1) and 7 (KEY2) of the MCU respectively, and the other end of AN1 and AN2 is connected to the bx terminal.

[0082] The following is combined Figure 1 The explanation is as follows: Figure 4 The connections of C1, R1, R2, diodes D1 and D2, Zener diode DW, filter capacitor C2, and anti-interference capacitor C3 form the power supply for the control circuit (RC step-down circuit), providing power to the microcontroller (MCU). Pins 8, 9, 10, 12, 13, and 14 of the MCU are connected to the pins of the digital tube display (C, B, AD, E, G, F) to form a six-position display circuit, corresponding to the display of numbers "1", "2", "3", "4", "5", and "6". Pins 5 (KEY1) and 6 (KEY2) of the MCU, connected to AN1 and AN2, form the operation circuit, where button AN1 is the power switch. (This circuit uses pin 5 of the MCU to receive pulse signals.) The control output port outputs a low or high level, or a corresponding periodic level for each gear position. This output circuit controls the actuator to turn the thyristor on or off. Button AN2 is for gear selection; operating button AN2 causes pin 6 (KEY2) to receive a pulse signal, cyclically selecting gear "1", "2", "3", "4", "5", and "6". Pin 7 (BH1) of the MCU is a high / low level receiving port (using a single receiving port). It receives the temperature limit level from the temperature-limiting resistor R4, which is determined by the temperature change of the load RL. This controls the output state of pin 1 (OUT) of the MCU, and through resistor R3, controls the on / off state of the actuator, allowing the load RL to be heated or de-heated, achieving temperature regulation and control functions. Figure 4The thyristor, the actuator of the full-wave circuit, is bidirectional. Therefore, diodes D3 and D4 are provided to ensure that pin 7 (BH1) of the MCU receive port can reliably receive high and low levels and pulse levels. Figure 4 The thyristor V, D3, R4, and pins 7 (BH1) and 1 (OUT) of the MCU form a half-wave temperature control circuit. The bidirectional thyristor V and D4 form another half-wave circuit, controlled by pin 1 (OUT) of the MCU. These two half-wave circuits are combined to form a full-wave temperature control circuit. In this embodiment, the timer operation time is the default time, with "6" being the highest temperature setting. The heating time relationship for temperature control settings "6", "5", "4", "3", "2", and "1" is: ta66 > ta56 > ta46 > ta36 > ta26 > ta16, and the non-heating time relationship is: tb66 ≤ tb56 ≤ tb46 ≤ tb36 ≤ tb26 ≤ tb16. Its operating principle is the same as above. Figure 3 The circuitry will not be described here.

[0083] In addition, other devices, such as dedicated chips and integrated circuits, can also be made using the above principles and combinations of single or multiple circuits.

[0084] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0085] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electric heating appliance with easily adjustable temperature, comprising a heating carrier (1), a heating element (2), an interface fixing box (3), a connecting cord (4), a controller (5), and a power plug (6), wherein the heating element (2) is mounted on the heating carrier (1), and the interface fixing box (3), which is a power inlet at one end of the heating carrier (1), is connected to the controller (5) via the connecting cord (4) and connected to the power supply via the power plug (6), wherein the controller (5) includes a housing and a control circuit installed therein, the control circuit including a working power supply, characterized in that: The power supply provides operating voltage for the microcontroller and its associated operating, display, and auxiliary circuits. The microcontroller outputs a periodic high- and low-level signal to control the conduction or cutoff of the actuators, thus forming a temperature regulation and temperature limiting circuit. The temperature regulation circuit is composed of the microcontroller's operation circuit port c, the display circuit port d, the output port a, and the output circuit resistor R0 to the actuator. The temperature limiting circuit consists of a microcontroller port b receiving high and low voltage levels from the temperature limiting resistor R, which is then processed to control the output state of the microcontroller's output port.

2. The electric heating appliance with convenient temperature control according to claim 1, characterized in that: In the temperature regulation circuit, the microcontroller output port a outputs one or more cycle levels.

3. The electric heating appliance with convenient temperature control according to claim 1, characterized in that: In the temperature limiting circuit, the microcontroller's high and low level receiving port processes the received limiting level and the high-low conversion level within the microcontroller to change the output state of the output port, and controls the conduction and cutoff of the actuator through resistor R0.

4. The electric heating appliance with convenient temperature control according to claim 2, characterized in that: The microcontroller has one or more output ports that accept high and low levels.

5. The electric heating appliance with convenient temperature control according to claim 3, characterized in that: The microcontroller has one or more output ports a.

6. The electric heating appliance with convenient temperature control according to claim 3, characterized in that: The actuator mainly consists of a thyristor, a field-effect transistor, a switching transistor, and a relay.

7. The electric heating appliance with convenient temperature control according to claim 3, characterized in that: The microcontroller has a fine-tuning voltage circuit to adjust the working voltage. In conjunction with the pulse voltage change on the temperature limiting resistor R, the microcontroller receives the pulse voltage from any port, processes it internally, and outputs a low-level or high-level signal to the output port to control the cut-off or conduction of the actuator.

8. The electric heating appliance with convenient temperature control according to claim 1, characterized in that: The power source can be one of AC, DC, or a mobile power source.

9. The electric heating appliance with convenient temperature control according to claim 1, characterized in that: The heating element (2) is composed of a single heating wire or heating plate, and its structure is one of a single spiral, straight wire, carbon fiber wire, carbon film, or graphene film.

10. An electric heating appliance with convenient temperature control according to claim 1, characterized in that: The interface fixing box (3) has two single-control interface contacts and three double-control interface contacts.

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