阅读说明：本技术 一种加热控制电路、加热电器 (Heating control circuit and heating electric appliance ) 是由 陈小平 唐华龙 于 2020-05-19 设计创作，主要内容包括：本申请公开了一种加热控制电路、加热电器,包括：用于连接交流电的输入端、连接于输入端的PTC加热器、与PTC加热器串联的可控硅,与可控硅并联的继电器、与输入端相连接的过零点采样电路,以及控制器,过零点采样电路用于检测交流电的过零点；其中,当满足预设条件时,控制器控制继电器断开,以及根据过零点采样电路检测到的过零点控制可控硅的导通角,以调节降低PTC加热器的启动功率；当不满足预设条件时,控制器控制可控硅截止,并控制继电器闭合。通过控制并联的可控硅与继电器的通断,能够较好地控制PTC加热器的工作功率,防止出现跳闸,极大提高了加热电器运行的可靠性。(The application discloses heating control circuit, heating electrical apparatus includes: the device comprises an input end for connecting alternating current, a PTC heater connected with the input end, a controlled silicon connected with the PTC heater in series, a relay connected with the controlled silicon in parallel, a zero crossing point sampling circuit connected with the input end and a controller, wherein the zero crossing point sampling circuit is used for detecting the zero crossing point of the alternating current; when the preset condition is met, the controller controls the relay to be switched off, and controls the conduction angle of the controlled silicon according to the zero crossing point detected by the zero crossing point sampling circuit so as to adjust and reduce the starting power of the PTC heater; and when the preset condition is not met, the controller controls the silicon controlled rectifier to be cut off and controls the relay to be closed. By controlling the on-off of the parallel-connected silicon controlled rectifier and the relay, the working power of the PTC heater can be well controlled, tripping is prevented, and the running reliability of the heating electric appliance is greatly improved.)

1. A heating control circuit, comprising: the device comprises an input end for connecting alternating current, a PTC heater connected with the input end, a controlled silicon connected with the PTC heater in series, a relay connected with the controlled silicon in parallel, a zero crossing point sampling circuit connected with the input end and a controller, wherein the zero crossing point sampling circuit is used for detecting the zero crossing point of the alternating current;

when a preset condition is met, the controller controls the relay to be switched off, and controls the conduction angle of the controlled silicon according to a zero crossing point detected by the zero crossing point sampling circuit so as to adjust and reduce the starting power of the PTC heater; and when the preset condition is not met, the controller controls the silicon controlled rectifier to be cut off and controls the relay to be closed.

2. The heating control circuit according to claim 1, wherein the satisfaction of the preset condition includes the temperature of the PTC heater being equal to or less than a preset temperature threshold; or, the meeting of the preset condition includes that the operation time of the PTC heater is less than or equal to a preset time threshold.

3. The heating control circuit according to claim 1, wherein the thyristor comprises a triac, and the controller controls the triac to be turned on for a preset time period after each detection of the zero-crossing point to adjust the reduction of the activation power of the PTC heater.

4. The heating control circuit of claim 3, further comprising a triac control unit, wherein the triac control unit is connected to the triac, and the triac control unit sends a trigger pulse to a control electrode of the triac according to the control command after receiving the control command sent by the controller, so that the triac is turned on for a preset duration, and the preset duration is less than or equal to one-half cycle of the alternating current.

5. The heating control circuit of claim 1, further comprising a relay control unit connected to the relay for controlling the relay to be turned on or off according to a received control command sent by the controller.

6. A heating control circuit according to any of claims 1 to 5 further comprising a temperature controller connected in series with the PTC heater, the temperature controller being configured to disconnect power to the PTC heater when the temperature of the PTC heater is above a specified value.

7. The heating control circuit according to any one of claims 1 to 5, wherein the zero-crossing point sampling circuit includes a sampling resistor connected to the input terminal, a zener diode connected to the sampling resistor at one end and grounded at the other end, and a capacitor connected in parallel with the zener diode.

8. The heating control circuit according to any one of claims 1 to 5, further comprising a filter circuit connected in parallel with the relay and the thyristor to remove a spike voltage of the alternating current.

9. Heating appliance, characterized in that it comprises a heating control circuit according to any one of claims 1 to 8.

10. The heating appliance of claim 9, wherein the heating appliance comprises at least one of a bath heater, an air conditioner, a dryer, an electric heater, and an electric iron.

Technical Field

The application relates to the technical field of electronic devices, in particular to a heating control circuit and a heating electric appliance.

Background

The PTC heater is a device composed of a PTC ceramic heating element and an aluminum pipe, and is widely applied to heating appliances such as a fan heater, a bath heater and the like at present. The PTC heater is characterized by a relatively low internal resistance in a cold state and a large current immediately after starting, resulting in a large starting power of the heating appliance. For example, the nominal heating power of an appliance partially equipped with a PTC heater is 2KW, and when the PTC heater is started in a cold state, the starting power of the appliance may reach 3KW or more, and then the real-time power of the appliance slowly decreases as the temperature of the PTC heater increases. In this case, when the heating appliance is just started, if the power of the socket allocated to the heating appliance by the user is insufficient, a trip situation is likely to occur in the home of the user.

Disclosure of Invention

In order to overcome the defects of the prior art, the application aims to provide a heating control circuit and a heating electric appliance, when a PTC heater is started in a cold state, the working power of the PTC heater can be well controlled by controlling the on-off of a thyristor and a relay which are connected in parallel, so that the running reliability of the heating electric appliance is improved, and the cost is saved.

A first aspect of the present application provides a heating control circuit comprising:

the device comprises an input end for connecting alternating current, a PTC heater connected with the input end, a controlled silicon connected with the PTC heater in series, a relay connected with the controlled silicon in parallel, a zero crossing point sampling circuit connected with the input end and a controller, wherein the zero crossing point sampling circuit is used for detecting the zero crossing point of the alternating current;

when a preset condition is met, the controller controls the relay to be switched off, and controls the conduction angle of the controlled silicon according to a zero crossing point detected by the zero crossing point sampling circuit so as to adjust and reduce the starting power of the PTC heater; and when the preset condition is not met, the controller controls the silicon controlled rectifier to be cut off and controls the relay to be closed.

A second aspect of the present application provides a heating appliance comprising a heating control circuit as described above.

Compared with the prior art, the beneficial effects of the embodiment of the application are that: the controller controls the PTC heater by controlling the silicon controlled rectifier and the relay which are connected in parallel, and when a preset condition is met, the controller controls the relay to be disconnected and controls the conduction angle of the silicon controlled rectifier according to a zero crossing point detected by the zero crossing point sampling circuit so as to adjust and reduce the starting power of the PTC heater; and when the preset condition is not met, the controller controls the silicon controlled rectifier to be cut off and controls the relay to be closed. When the PTC heater is started in a cold state, the working power of the PTC heater can be well controlled by controlling the on-off of the parallel-connected silicon controlled rectifier and the relay, so that the running reliability of the heating electric appliance is improved.

Drawings

FIG. 1 is a schematic circuit diagram of an embodiment of a heating control circuit provided in an example of the present application;

FIG. 2 is a schematic circuit diagram of another embodiment of a heating control circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a heating apparatus according to an embodiment of the present application.

Detailed Description

The present application is further described with reference to the accompanying drawings and the detailed description, and it should be noted that, in the present application, the embodiments or technical features described below may be arbitrarily combined to form a new embodiment without conflict.

Fig. 1 is a schematic circuit diagram of the heating control circuit.

As shown in fig. 1, the heating control circuit 100 includes an input terminal 101, a PTC heater 102, a thyristor 103, a relay 104, a zero-crossing point sampling circuit 105, and a controller 106.

In some embodiments, as shown in fig. 1 and 2, the input terminal 101 may be an ac power input terminal for connecting to an ac power source to provide ac power to the devices of the heating control circuit 100.

The PTC heater 102 is connected to the input terminal 101, and the PTC heater 102 has low thermal resistance and high heat exchange efficiency, and can efficiently convert the electric energy provided by the input terminal 101 into heat energy. Moreover, the PTC heater 102 has high safety performance, and the phenomenon of 'red' on the surface of an electric heating tube heater can not be generated under any application condition, so that safety accidents such as scalding, fire and the like are not easy to happen.

The silicon controlled rectifier 103 is connected in series with the PTC heater 102, and the silicon controlled rectifier 103 includes a one-way silicon controlled rectifier and/or a two-way silicon controlled rectifier for controlling the PTC heater 102. A relay 104 is connected in parallel with the thyristor 103, i.e. the relay 104 is also connected in series with the PTC heater 102, the relay 104 includes at least one of an electromagnetic relay, a temperature relay, a time relay, and the like, and the PTC heater 102 is also controlled by the relay 104. Advantageously, by controlling the PTC heater 102 in parallel with the relay 104 through the thyristor 103, the operating power of the PTC heater 102 can be better controlled, thereby improving the reliability of the operation of the heating appliance.

Illustratively, when the PTC heater 102 needs to be heated, but the PTC heater 102 is in a cold state, the control relay 104 is turned off, and the thyristor 103 is turned on, so that the instantaneous power generated by the characteristics of the PTC heater 102 can be greatly reduced, the tripping of a switch in the home of a user can be avoided, and the reliability of the circuit can be improved.

Illustratively, after the PTC heater 102 is heated for a period of time, the thyristor 103 is controlled to be turned off, and the relay 104 is turned on, at this time, the PTC heater 102 is controlled not by the thyristor 103 but by the relay 104 for three reasons: firstly, the calculation amount required for controlling the PTC heater 102 by the thyristor 103 is large; secondly, the on-resistance of the thyristor 103 is much larger than that of the relay 104, and the radiator is required to be additionally arranged nearby the thyristor 103 for long-time large-current work, so that the control cost is not facilitated; thirdly, as the PTC heater 102 is heated up, the operating power thereof is continuously reduced, and the operating power of the PTC heater 102 can be increased by controlling the relay 104 to be turned on, thereby increasing the heating efficiency of the PTC heater 102.

In some embodiments, a zero-crossing sampling circuit 105 is connected to the input 101, and the zero-crossing sampling circuit 105 is configured to detect a zero-crossing of the alternating current provided through the input 101. Wherein the zero-crossing point of the alternating current may be a point in the alternating current at which the voltage value is zero. It will be appreciated that the zero crossing sampling circuit 105 includes a zero crossing detection optocoupler.

As shown in fig. 1 and 2, the zero-crossing sampling circuit 105 includes a sampling resistor R2 connected to the input terminal 101, a zener diode ZD1 having one end connected to the sampling resistor R2 and the other end grounded, and a capacitor C2 connected in parallel to the zener diode ZD 1.

Illustratively, the zero-point sampling circuit 105 generates a zero-point detection signal each time a zero-point of the alternating current is detected, and transmits the zero-point detection signal to the controller 106 for the controller 106 to perform subsequent operations based on the zero-point detection signal.

As shown in fig. 1 and 2, the controller 106 is connected to the zero-point sampling circuit 105, for example, the zero-point sampling circuit 105 is connected to an I/O interface of the controller 106. It should be noted that the controller 106 can control various devices in the circuit, such as the relay 104 and the thyristor 103. In addition, other components may be connected between the controller 106 and the zero-point sampling circuit 105, for example, the zero-point sampling circuit 105 may also be connected to other interfaces of the controller 106, which is not specifically limited in this application.

Illustratively, when a preset condition is satisfied, the controller 106 controls the relay 104 to be turned off, and controls the conduction angle of the thyristor 103 to adjust and reduce the starting power of the PTC heater 102 according to the zero-crossing point detected by the zero-crossing point sampling circuit 105. Advantageously, the controller 106 controls the conduction angle of the thyristor 103 according to the zero crossing point, so that the starting current of the PTC heater 102 is reduced, the maximum instantaneous power generated by the cold state of the PTC heater 102 can be effectively reduced, the tripping of a switch in the home of a user is avoided, and the circuit is protected from being damaged by large current.

Illustratively, when the preset condition is not met, the controller 106 controls the thyristor 103 to be turned off and controls the relay 104 to be closed. It should be noted that, the relay 104 is powered on through the coil of the control end to generate a magnetic field and attract the iron sheet of the strong current end, so as to achieve the effect of controlling strong current by weak current; the silicon controlled rectifier 103 has a PN junction therein, which has a large on-resistance, and generates a large amount of heat when a large current is applied. Therefore, the PTC heater 102 is controlled by the relay 104, so that a heat sink required for a high heat generated by the long-time operation of the thyristor 103 can be saved, the cost can be well controlled, and the heating efficiency of the PTC heater 102 can be improved.

In some embodiments, the satisfying of the preset condition includes: the temperature of the PTC heater 102 is equal to or less than a preset temperature threshold. Specifically, the heating control circuit 100 further includes a temperature sensor connected to the PTC heater 102 for collecting temperature information of the PTC heater 102 and transmitting the collected temperature information to the controller 106 in real time or at preset intervals. It is understood that the preset temperature threshold may be set according to actual situations, and this application is not particularly limited to this, and optionally, the preset temperature threshold is 50 degrees.

In other embodiments, the satisfying of the preset condition includes: the operating time period of the PTC heater 102 is equal to or less than the preset time period threshold. The operation time period is the time period from the start of heating to the end of heating of the PTC heater 102. Specifically, the heating control circuit 100 further includes a timer connected to the PTC heater 102, which starts to count time whenever the PTC heater 102 is turned on and starts to operate, thereby obtaining the operation duration information of the PTC heater 102, and transmits the collected operation duration information to the controller 106 in real time or at preset intervals. It is to be understood that the preset time threshold may be set according to practical situations, and this application is not specifically limited to this, and optionally, the preset time threshold is 20 seconds.

In some embodiments, as shown in fig. 1 and 2, the thyristor 103 comprises a triac Q1, and the controller 106 controls the triac Q1 to conduct for a preset time period after each detection of a zero crossing of the alternating current by the zero sampling circuit 105 to adjust the reduction of the start-up power of the PTC heater 102. The preset duration can be flexibly set by a user.

Illustratively, when the PTC heater 102 needs to be heated, the relay 104 is in an off state, the controller 106 sends a pulse control signal to the triac 103 according to the zero-crossing detection signal, the pulse control signal can control the conduction angle of the triac Q1, the triac 103 receives the pulse control signal sent by the controller 106, and controls the triac Q1 to be switched on at a specified time according to the pulse control signal, and is switched off at the next zero-crossing point, and is switched on again when reaching the conduction point, and the steps are repeated, so that the triac 103 is controlled to be switched on for a preset time length to adjust and reduce the starting power of the PTC heater 102 during heating.

As shown in fig. 2, the heating control circuit 200 further includes a triac control unit 201, the triac control unit 201 is connected to the triac Q1, and after receiving a control command sent by the controller 106, the triac control unit 201 sends a trigger pulse to the control electrode of the triac Q1 according to the control command, so that the triac Q1 is turned on for a preset time.

The preset time duration is less than or equal to one half cycle of the alternating current, and optionally, the preset time duration is one quarter cycle of the alternating current. It should be noted that by controlling the magnitude or timing of the trigger pulse applied to the control electrode of triac Q1, the on current to triac Q1 can be adjusted to control the current to PTC heater 102.

In some embodiments, as shown in fig. 2, the heating control circuit 200 further includes a relay control unit 202, and the relay control unit 202 is connected to the relay 104 and configured to control the relay 104 to be turned on or off according to a received control command sent by the controller 106.

For example, relay 104 is an electromagnetic relay RY1, and electromagnetic relay RY1 may include an electromagnet and an armature. When the PTC heater 102 needs to be heated, the controller 106 sends a first control instruction to the relay control unit 202, and the relay control unit 202 controls the electromagnet of the electromagnetic relay RY1 to lose the magnetic field according to the received first control instruction, so that the armature is disconnected and the electromagnetic relay is turned off.

For example, when the PTC heater 102 needs to stop heating, the controller 106 sends a second control instruction to the relay control unit 202, and the relay control unit 202 controls the electromagnet of the electromagnetic relay RY1 to generate a magnetic field according to the second control instruction according to the received second control instruction, so as to attract the armature to act, and thus communicate the output circuit of the electromagnetic relay RY 1.

As shown in fig. 2, the heating control circuit 200 further includes a temperature controller 203, the temperature controller 203 is connected in series with the PTC heater 102, and when the temperature of the PTC heater 102 is higher than a predetermined value, the power supply to the PTC heater 102 is cut off. It should be noted that the thermostat 203 includes a thermal switch, and the specific value can be set according to actual conditions, and optionally, the specific value is 100 degrees. Advantageously, the temperature controller 203 can ensure that the temperature of the PTC heater 102 is not higher than a specific value, thereby improving the safety and reliability of the circuit.

Further, as shown in fig. 1 and 2, the heating control circuit 100 (or the heating control circuit 200) further includes a filter circuit connected in parallel with the relay 104 and the thyristor 103 to remove a spike voltage of the alternating current. For example, the filter circuit comprises a resistor R1 and a capacitor C1, which protect the relay 104 and the thyristor 103 from damage due to the spike voltage of the alternating current.

In the heating control circuit provided by the embodiment of the specification, the controller controls the PTC heater by controlling the silicon controlled rectifier and the relay which are connected in parallel, and when the preset condition is met, the controller controls the relay to be disconnected and controls the conduction angle of the silicon controlled rectifier according to the zero crossing point detected by the zero crossing point sampling circuit so as to adjust and reduce the starting power of the PTC heater; and when the preset condition is not met, the controller controls the silicon controlled rectifier to be cut off and controls the relay to be closed. When the PTC heater is started in a cold state, the working power of the PTC heater can be well controlled by controlling the on-off of the parallel-connected silicon controlled rectifier and the relay, so that the running reliability of the heating electric appliance is improved, and the cost is saved.

Please refer to fig. 3 in conjunction with the foregoing embodiments, fig. 3 is a schematic structural diagram of a heating appliance provided in the embodiments of the present application.

As shown in fig. 3, the heating appliance 30 includes: the heating control circuit 300 described above. The heating device 30 includes a bathroom heater, an air conditioner, a hot air curtain machine, a dehumidifier, a dryer, a clothes dryer, a fan heater and other devices which need to provide hot air, and further includes an electric mosquito dispeller, a massager, an electric heater, an electric iron, a hair curler, a hair straightener, a gluing machine, an electric perfuming machine, a hot melt glue gun and other devices which need to provide heating.

In the heating electric appliance provided by the embodiment of the specification, the controller controls the PTC heater by controlling the silicon controlled rectifier and the relay which are connected in parallel, and when the preset condition is met, the controller controls the relay to be disconnected and controls the conduction angle of the silicon controlled rectifier according to the zero crossing point detected by the zero crossing point sampling circuit so as to adjust and reduce the starting power of the PTC heater; and when the preset condition is not met, the controller controls the silicon controlled rectifier to be cut off and controls the relay to be closed. When the PTC heater is started in a cold state, the working power of the PTC heater can be well controlled by controlling the on-off of the parallel-connected silicon controlled rectifier and the relay, and the tripping of a switch caused by large current generated when the PTC heater is started in the cold state is prevented, so that the reliability and the safety of the operation of a heating appliance are improved.

In the description of the present application, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless otherwise explicitly stated or limited. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The above disclosure provides many different embodiments or examples for implementing different structures of the application. The components and arrangements of specific examples are described above to simplify the present disclosure. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

In the description herein, references to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited thereto, and any insubstantial changes and substitutions made by those skilled in the art based on the present application are intended to be covered by the present application.