Wide-voltage heating device and device

Abstract

The utility model discloses a wide-voltage heating device which comprises a power plug, a first heating component, a second heating component and a control circuit board. The control circuit board comprises a voltage sampling circuit, a first relay, a second relay and a controller; a first contact of the first relay is connected with a first electrode of the power plug, and a second contact of the first relay is electrically connected with a first end of the first heating component and a first end of the second heating component; a normally open contact of the second relay is electrically connected with the first electrode, a normally closed contact of the second relay is electrically connected with a second electrode of the power plug, and a common contact of the second relay is electrically connected with a second end of the first heating component; the other end of the second heating component is electrically connected with the second electrode; and the controller is used for identifying an input AC voltage range according to the output voltage of the voltage sampling circuit, changing the working states of the first relay and the second relay, controlling series connection, parallel connection and automatic power off of heating components, and being suitable for wide voltage heating control of different power grid voltages.

Description

Technical Field

[0001] The utility model relates to the field of electronic technology, and particularly relates to a wide-voltage heating device and an apparatus. Background Art

[0002] At present, there are generally two types of voltages used for indoor electricity in various countries around the world, namely 100V - 130V and 220 - 240V. 100V, 110 - 130V are classified as low voltages, such as the voltages in the United States, Japan, etc. and on ships; 220 - 240V is called high voltage, which includes 220 volts in China, 230 volts in the UK and many European countries. In countries using 220 - 240V voltage, there are also cases where 110 - 130V voltage is used, such as Sweden and Russia.

[0003] Currently, steam ironing products such as electric irons and handheld steam ironing machines on the market generally only apply one voltage during use, that is, the circuit boards in these products cannot effectively achieve wide-voltage use. Since the standard power supply voltages in different countries are different, such products are difficult to meet the needs of carrying and using during travel. Therefore, there is an urgent need for a product suitable for wide-voltage operation to meet the market demand, that is, the product can operate normally at both low voltage and high voltage.

[0004] Patent CN211694813U discloses a wide-voltage steam generator, which includes a steam generation unit and a control circuit board electrically connected to the steam generation unit. The steam generation unit includes a power supply connector, a temperature control switch electrically connected to the first power supply electrode of the power supply connector, and a first heating element and a second heating element electrically connected between the temperature control switch and the second power supply electrode of the power supply connector. The voltage sampling circuit in the control circuit board can detect the supply voltage situation, and then automatically control the connection state switching unit to connect with the first heating element and the second heating element, so that the steam generator can operate normally under different supply voltages. And during the operation of the steam generator, both the first heating element and the second heating element can participate in the operation, realizing the full utilization of the heating elements. Such products usually use a temperature control switch based on a bimetallic strip for power-off control, with general temperature control accuracy. At the same time, when using a temperature control switch, when power is on, there must be a heating circuit conducting, and it is impossible to completely not heat. Summary of the Utility Model

[0005] The utility model aims to provide a wide-voltage heating device to solve at least one of the above technical problems, and the following technical solutions are given:

[0006] A wide-voltage heating device, characterized by comprising a power plug, a first heating element, a second heating element and a control circuit board;

[0007] The control circuit board includes a voltage sampling circuit, a first relay, a second relay, and a controller;

[0008] The first relay includes a first contact and a second contact. In the closed state, the first contact and the second contact are short - circuited; the second relay includes a normally - open contact, a normally - closed contact, and a common contact. In the closed state, the normally - open contact and the common contact are short - circuited, and the normally - closed contact and the common contact are disconnected;

[0009] For the first relay, its first contact is connected to the first electrode of the power plug, and its second contact is electrically connected to the first end of the first heating element and the first end of the second heating element;

[0010] For the second relay, its normally - open contact is electrically connected to the first electrode; its normally - closed contact is electrically connected to the second electrode of the power plug; its common contact is electrically connected to the second end of the first heating element;

[0011] The other end of the second heating element is electrically connected to the second electrode;

[0012] The controller is electrically connected to the first relay, the second relay, and the voltage sampling circuit respectively, and is used to identify the range of the input AC voltage according to the output voltage of the voltage sampling circuit and change the working states of the first relay and the second relay.

[0013] Further, the first relay is a single - pole single - throw relay; the second relay is a single - pole double - throw relay.

[0014] Further, the types of the first heating element and the second heating element are electric heating tubes, electric heating wires, or electric heating sheets.

[0015] Further, a temperature sensor is also included, and the temperature sensor is electrically connected to the controller.

[0016] Further, the temperature sensor is an NTC sensor.

[0017] Further, the temperature sensor is electrically connected to an IO port of the controller through a resistor and is also electrically connected to another IO port of the controller through an RC filter circuit.

[0018] Further, the voltage sampling circuit includes a rectifying and filtering circuit and a voltage - dividing circuit connected in sequence; the input of the rectifying and filtering circuit is electrically connected to the first electrode, and the output of the voltage - dividing circuit is electrically connected to the AD port of the controller.

[0019] Further, the wide - voltage heating device is an electric iron or a steam iron, and the first heating element and the second heating element are electric heating tubes.

[0020] Further, the wide-voltage heating device is an electric kettle, and the first heating element and the second heating element are electric heating tubes.

[0021] The present utility model achieves the following technical effects:

[0022] In a specific embodiment, the wide-voltage heating device of the present utility model supports the series connection, parallel connection and automatic power-off control of the heating elements, and is suitable for wide-voltage heating control during travel.

[0023] In a specific embodiment, the wide-voltage heating device of the present utility model uses an NTC temperature sensor for temperature control, with high temperature control accuracy; and when not working, it can automatically turn off the heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the circuit diagram of the heating circuit of the wide-voltage heating device of the present utility model;

[0025] Figure 2 is the schematic diagram of the current path when the wide-voltage heating device of the present utility model works at 220V - 240V;

[0026] Figure 3 is the schematic diagram of the current path when the wide-voltage heating device of the present utility model works at 100V - 130V;

[0027] Figure 4 is the circuit diagram of the power supply circuit, voltage sampling circuit and other circuits of the wide-voltage heating device of the present utility model;

[0028] Figure 5 is the circuit diagram of the controller and temperature sensor circuit of the wide-voltage heating device of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To further illustrate the embodiments, the present utility model provides drawings. These drawings are part of the disclosure of the present utility model, mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principle of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present utility model.

[0030] The present utility model will be further described below in conjunction with the drawings and specific embodiments.

[0031] As Figure 1As shown in the figure, the present utility model provides a wide-voltage heating device, which is applied to heating devices such as steam irons for travel. The circuit consists of heating components such as two electric heating tubes to form a heater. Without setting a temperature control switch, the input AC voltage can be identified through a voltage sampling circuit to determine whether the input AC voltage is in the range of 100V - 130V or between 220V - 240V. A double-relay is used to switch the series or parallel states of the heating components such as the two electric heating tubes, and the entire heater can be turned off when not in use, so that the entire heater does not work to achieve the self-power-off function. The NTC temperature sensor is used for temperature monitoring to achieve functions such as NTC temperature control.

[0032] Specifically, the wide-voltage heating device consists of a power plug, electric heating tube HEAT1, electric heating tube HEAT2, and a control circuit board, etc. The control circuit board consists of relays K1, K2, MCU U2, and an NTC (negative temperature coefficient) temperature sensor, etc. Among them, relay K1 is a normally open relay (single-pole single-throw relay), including a first contact and a second contact. Relay K2 is a changeover relay (single-pole double-throw relay), including a normally open contact, a normally closed contact, and a common contact.

[0033] The first contact of relay K1 is connected to the electrode ACL (live wire) in the power plug, and the second contact of relay K1 is connected to the first ends of electric heating tube HEAT1 and electric heating tube HEAT2.

[0034] The normally open contact of relay K2 is connected to the electrode ACL (live wire) in the power plug, and the normally closed contact is connected to the electrode ACN (neutral wire) in the power plug; its common contact is connected to the other end of electric heating tube HEAT1; the other end of electric heating tube HEAT2 is connected to the electrode ACN (neutral wire) in the power plug.

[0035] In specific applications, in addition to the electric heating tubes, the heating components can also be electric heating wires or electric heating sheets, etc., to meet the application requirements of different products.

[0036] It can be seen that:

[0037] As Figure 1 shown, after power-on, relay K1 is default in the off state, relay K2 is default in the off state, and the common contact and the normally closed contact of relay K2 are short-circuited and connected to electrode ACN. At this time, both ends of electric heating tubes HEAT1 and HEAT2 are connected to electrode ACN, and no loop is formed, so neither of the two electric heating tubes works.

[0038] As Figure 2As shown, when the MCU U2 detects that the voltage of the input alternating current is 220V - 240V, the relay K2 controls the switching of the heating circuit. When heating is required, the relay K2 is energized, forming a series heating circuit from the electrode ACL (live wire), relay K2, electric heating tubes HEAT1, HEAT2 to the electrode ACN (neutral wire). The two electric heating tubes are used in series. When heating is not required, the relay K2 is turned off, no circuit is formed, and the electric heating tubes are powered off.

[0039] As Figure 3 shown, when the MCU U2 detects that the voltage of the input alternating current is 100V - 130V, the relay K1 controls the switching of the heating circuit. When heating is required, the relay K1 is energized, the normally open contact and the common contact are connected, and the current passes through the relay K1 from the electrode ACL (live wire) and then returns to the electrode ACN (neutral wire) from the two electric heating tubes HEAT1 and HEAT2 respectively. The electric heating tubes are used in parallel. When heating is not required, the relay K1 is disconnected and no circuit is formed.

[0040] Figure 4 and Figure 5 Examples of circuit parts such as the power supply circuit, voltage detection circuit, and MCU U2 of the control board circuit are given. The voltage detection circuit consists of D3, C6, R5, R6, and C7, etc. D3 and C6 form a rectifier filter circuit to convert alternating current into direct current; R5 and R6 form a voltage dividing circuit to reduce the rectified high-voltage direct current to within the voltage limit range of the AD sampling port of the MCU U2, so that the input voltage value can be accurately read. By simple data processing such as threshold comparison, it can be judged whether the input voltage is in the range of 100V - 130V or 220V - 240V. By selecting suitable device parameters, it can be set that when 220V - 240V is input to the electrode ACL, the output of the voltage detection circuit is greater than 3V and less than 5V; when 110V - 130V is input to the electrode ACL, the output of the voltage detection circuit is less than 2V, which is convenient.

[0041] The power supply circuit consists of R1, CX1, TVR1, D1, D2, L1, C2, chip U1 and its peripheral circuits, and outputs a power supply of +5V to supply power to the MCU U2 and the relay, etc. Among them, the chip U1 is a step-down type power management chip, and CX1 and TVR1 provide AC input protection.

[0042] In this embodiment, the output of the NTC temperature sensor is grounded through the resistor R24 and outputs the Temp1 signal through the resistor R26; and outputs the NTC signal after passing through the integration circuit (filter circuit) composed of R25 and C2. Precise temperature control can be achieved through the Temp1 signal and the NTC signal. When the temperature reaches a certain set threshold, the heating function is started or stopped.

[0043] The utility model achieves the following technical effects:

[0044] In a specific embodiment, the wide-voltage heating device supports the series connection, parallel connection and automatic power-off control of heating components, and is suitable for wide-voltage heating control under different grid voltages during international travel.

[0045] In a specific embodiment, the wide-voltage heating device uses an NTC temperature sensor for temperature control, with high temperature control accuracy; and when not working, it can automatically turn off the heater.

[0046] This circuit can also be applied to heating devices such as electric kettles for travel, and is suitable for wide-voltage heating control during travel; it can accurately control the temperature, the heating is more stable, and there will be no repeated heating. In this application, the heating component is preferably an electric heating tube.

[0047] Although the utility model is specifically shown and described in combination with the preferred implementation, those skilled in the art should understand that various changes can be made to the utility model in terms of form and details without departing from the spirit and scope of the utility model defined by the appended claims, and all of them are within the protection scope of the utility model.

Claims

1. A wide-voltage heating device, characterized in that: It includes a power plug, a first heating component (HEAT1), a second heating component (HEAT2), and a control circuit board; The control circuit board includes a voltage sampling circuit, a first relay (K1), a second relay (K2), and a controller (U2); The first relay (K1) includes a first contact and a second contact. In the closed state, the first contact and the second contact are short - circuited; The second relay (K2) includes a normally - open contact, a normally - closed contact, and a common contact. In the closed state, the normally - open contact and the common contact are short - circuited, and the normally - closed contact and the common contact are disconnected; For the first relay (K1), its first contact is connected to the first electrode (ACL) of the power plug, and its second contact is electrically connected to the first end of the first heating component (HEAT1) and the first end of the second heating component (HEAT2); For the second relay (K2), its normally - open contact is electrically connected to the first electrode (ACL); Its normally - closed contact is electrically connected to the second electrode (ACN) of the power plug; Its common contact is electrically connected to the second end of the first heating component (HEAT1); The other end of the second heating component (HEAT2) is electrically connected to the second electrode (ACN); The controller (U2) is electrically connected to the first relay (K1), the second relay (K2), and the voltage sampling circuit respectively, and is used to identify the input AC voltage range according to the output voltage of the voltage sampling circuit and change the working states of the first relay (K1) and the second relay (K2).

2. The wide-voltage heating device according to claim 1, wherein: The first relay (K1) is a single - pole single - throw relay; The second relay (K2) is a single - pole double - throw relay.

3. The wide-voltage heating device according to claim 1, characterized in that: The types of the first heating component (HEAT1) and the second heating component (HEAT2) are electric heating tubes, electric heating wires, or electric heating sheets.

4. The wide-voltage heating device according to claim 1, wherein: It further includes a temperature sensor, and the temperature sensor is electrically connected to the controller (U2).

5. The wide-voltage heating device according to claim 4, wherein: The temperature sensor is an NTC sensor.

6. The wide-voltage heating device according to claim 5, wherein: The temperature sensor is electrically connected to an IO port of the controller (U2) through a resistor and is electrically connected to another IO port of the controller (U2) through an RC filter circuit.

7. The wide-voltage heating device according to claim 1, wherein: The voltage sampling circuit includes a rectifying and filtering circuit and a voltage - dividing circuit connected in sequence; The input of the rectifying and filtering circuit is electrically connected to the first electrode (ACL), and the output of the voltage - dividing circuit is electrically connected to a certain AD port of the controller (U2).

8. The wide-voltage heating device according to any one of claims 1 to 7, characterized in that: The wide - voltage heating device is an electric iron or a steam iron, and the first heating component (HEAT1) and the second heating component (HEAT2) are electric heating tubes.

9. The wide-voltage heating device according to any one of claims 1-7, characterized in that: The wide - voltage heating device is an electric kettle, and the first heating component (HEAT1) and the second heating component (HEAT2) are electric heating tubes.

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