Heating wire heating control circuit

Abstract

The utility model discloses a heating wire heating control circuit, which comprises a power supply circuit, a control circuit, a control end and a heating circuit, the power supply circuit is electrically connected with a mains supply, the control circuit, the control end and the heating circuit, the control circuit comprises a control module and is electrically connected with the power supply circuit, and the control end is electrically connected with the heating circuit. The heating circuit is electrically connected with the power supply circuit and the control end, and a first silicon controlled rectifier module and a second silicon controlled rectifier module are arranged in the heating circuit. The working frequency of the power supply circuit is adjusted through the control circuit, so that the output voltage of the power supply circuit is adjusted, and elements in the isolated power supply are prevented from being broken down. Meanwhile, the first silicon-controlled module and the second silicon-controlled module replace the work of a relay, thereby preventing the control capability of the heating circuit from being reduced, and enabling the circuit to work more stably.

Description

Technical Field

[0001] This utility model relates to the field of heating wire control, specifically to a heating wire heating control circuit. Background Technology

[0002] In electric heating equipment, the main working element is the heating wire. The power supply for electric heating equipment is alternating current (AC), typically directly connected to the mains (220V AC). Since most electric heating equipment has a metal casing, and after prolonged use, the heating element may become energized due to insulation failure. Therefore, an isolation power supply is needed within the electric heating equipment to isolate the mains power from the control terminal. Common isolation methods include using transformers, optocouplers, etc., to block the direct electrical connection between the high-voltage side (power circuit) and the low-voltage side (control terminal). Isolation power supplies generally use electromagnetic isolation or optocoupler isolation to separate high and low voltage circuits. The maximum power these isolation power supplies can withstand is often limited by the withstand voltage threshold and thermal stability of the isolation components. Furthermore, the transformer coil turns in the isolation power supply are fixed, and the transformer's output voltage cannot be adjusted, which can easily lead to the breakdown of internal components.

[0003] Furthermore, such isolated power supplies often use relays as the main control switch. However, relays rely on internal magnetic contacts to engage and control the circuit on the high-voltage side. After prolonged use, the internal magnetic contacts will wear down, resulting in loose magnetic engagement and reduced control over the high-voltage side heating equipment. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a heating control circuit for an electric heating wire.

[0005] The objective of this utility model is achieved through the following solution:

[0006] A heating control circuit for an electric heating wire includes: a power supply circuit, a control circuit, a control terminal, and a heating circuit. The power supply circuit is connected to mains power and electrically connected to the control circuit, the control terminal, and the heating circuit respectively. The control circuit includes a control module electrically connected to the power supply circuit and the control terminal electrically connected to the heating circuit. The heating circuit includes a first working module and a second working module. The first working module includes a first optical isolation module, a first thyristor module, a first resistor, a second resistor, and a first heating module. The second working module includes a second optical isolation module, a second thyristor module, a third resistor, a fourth resistor, and a second heating module. The thermal module is electrically connected to the first optical isolation module, the first thyristor module, the first resistor, the second resistor, the control terminal, and the power supply circuit. The first thyristor module is electrically connected to the second resistor, the first heating module, the second optical isolation module, the second thyristor module, and the power supply circuit. The first resistor is electrically connected to the control terminal. The first heating module is electrically connected to the power supply circuit and the second heating module. The second optical isolation module is electrically connected to the second thyristor module, the third resistor, the fourth resistor, and the control terminal. The second thyristor module is electrically connected to the fourth resistor and the second heating module. The third resistor is electrically connected to the control terminal.

[0007] In one embodiment, the power supply circuit includes a first protection module, a first rectifier module, and a transformer module. The first protection module is electrically connected to the first rectifier module and the heating circuit, respectively. The first rectifier module is electrically connected to the transformer module, and the transformer module is electrically connected to the control module and the control terminal, respectively.

[0008] In one embodiment, the first protection module includes a first protection component and a first filter component, wherein the first protection component is electrically connected to the first filter component, the first rectifier module, the heating circuit and the mains power.

[0009] In one embodiment, the first rectifier module includes a bridge rectifier component BD and a second filter component. The bridge rectifier component BD has a positive input terminal and a negative input terminal. The positive input terminal and the negative input terminal of the bridge rectifier component BD are electrically connected to the first protection module and the second filter component, respectively. The second filter component is electrically connected to the transformer module and is grounded.

[0010] In one embodiment, the transformer module includes a second protection component, a third filter component, a first rectifier component, and a transformer T. The second protection component is electrically connected to the third filter component, the first rectifier component, the transformer T, the first rectifier module, and the control module, respectively. The third filter component is electrically connected to the first rectifier component and the transformer T, respectively. The first rectifier component is electrically connected to the transformer T and the control module, respectively. The transformer T is electrically connected to the control module and the control terminal, respectively.

[0011] In one embodiment, the transformer module further includes a withstand voltage component, which is electrically connected to the third filter component and the transformer module respectively.

[0012] In one embodiment, the control module includes a control chip, a third protection component, a fourth filter component, and a second rectifier component. The control chip has terminals 1-8. Terminal 1 of the control chip is electrically connected to the third protection component and the fourth filter component, respectively. Terminal 2 of the control chip is grounded. Terminal 3 of the control chip is electrically connected to the third protection component and the fourth filter component, respectively. Terminal 4 of the control chip is electrically connected to the third protection component. Terminals 5-8 of the control chip are electrically connected to the power supply circuit.

[0013] In one embodiment, the control terminal includes a control component and a voltage regulator module. The control component is electrically connected to the voltage regulator module, the first heating module, the second heating module, and the power supply circuit, respectively. The voltage regulator module is electrically connected to the heating circuit.

[0014] In one embodiment, the voltage regulator module includes a linear voltage regulator component U, a fourth protection component, and a fifth filter component; the linear voltage regulator component U is electrically connected to the fourth protection component, the fifth filter component, the control component, and the heating circuit, and the linear voltage regulator component U is grounded; the fourth protection component is electrically connected to the fifth filter component and the control component; the fifth filter component is electrically connected to the heating circuit, and the fifth filter component is grounded.

[0015] Compared with the prior art, the present invention has at least the following advantages:

[0016] The operating frequency of transformer T1 is adjusted by the control chip, thereby adjusting the output voltage of transformer T1 to prevent the internal components of the isolation power supply from being damaged. Simultaneously, the first and second thyristor modules replace the relays, preventing a decrease in the control capability of the first or second heating module, thus making the circuit operation more stable. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a circuit diagram of the heating control circuit for the heating wire.

[0019] In the attached figures, the reference numerals are as follows: 1. Power supply circuit; 11. First protection module; 111. First protection component; 112. First filter component; 12. First rectifier module; 121. Bridge rectifier component BD; 122. Second filter component; 13. Transformer module; 131. Second protection component; 132. Third filter component; 133. First rectifier component; 134. Withstand voltage component;

[0020] 2. Control circuit; 21. Control module; 211. Control chip; 212. Third protection component; 213. Fourth filter component; 214. Second rectifier component;

[0021] 3. Control terminal; 31. Control component; 32. Voltage regulator module; 321. Fourth protection component; 322. Fifth filtering component; 323. Linear voltage regulator component;

[0022] 4. Heating circuit; 41. First working module; 411. First optical isolation module; 412. First thyristor module; 413. First resistor; 414. Second resistor; 415. First heating module;

[0023] 42. Second working module; 421. Second optical isolation module; 422. Second thyristor module; 423. Third resistor; 424. Fourth resistor; 425. Second heating module. Detailed Implementation

[0024] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0025] It should be noted that all directional indicators in this utility model embodiment, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indicator will also change accordingly.

[0026] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0027] To further understand the utility model's content, features, and effects, the following embodiments are provided, along with detailed descriptions in conjunction with the accompanying drawings:

[0028] like Figure 1 As shown, Figure 1 This invention provides a circuit diagram of an electric heating wire heating control circuit, comprising: a power supply circuit 1, a control circuit 2, a control terminal 3, and a heating circuit 4. The power supply circuit 1 is electrically connected to the control circuit 2, the control terminal 3, the heating circuit 4, and mains power. The power supply circuit 1 supplies power to the control circuit 2, the control terminal 3, and the heating circuit 4. The control circuit 2 can adjust the voltage supplied by the power supply circuit 1 to the control terminal 3 and the heating circuit 4. In operation, the heating circuit 4 is controlled via the control terminal 3, thereby controlling the operation of the heating circuit 4.

[0029] Furthermore, such as Figure 1As shown, the control circuit 2 includes a control module 21, which is electrically connected to the power supply circuit 1. The control terminal 3 is electrically connected to the heating circuit 4. The heating circuit 4 includes a first working module 41 and a second working module 42. The first working module 41 includes a first optical isolation module 411, a first thyristor module 412, a first resistor 413, a second resistor 414, and a first heating module 415. The second working module 42 includes a second optical isolation module 421, a second thyristor module 422, a third resistor 423, a fourth resistor 424, and a second heating module 425. The first optical isolation module 411 is connected to the first thyristor module 422, the first resistor 413, the second resistor 414, and the first heating module 415. Resistor 414 and control terminal 3 are electrically connected respectively. The first thyristor module 412 is electrically connected to the second resistor 413, the first heating module 415, the second optical isolation module 421, the second thyristor module 422 and the power supply circuit 1 respectively. The first resistor 413 is electrically connected to control terminal 3. The first heating module 415 is electrically connected to power supply circuit 1 and the second heating module 425 respectively. The second optical isolation module 421 is electrically connected to the second thyristor module 422, the third resistor 423, the fourth resistor 424 and control terminal 3 respectively. The second thyristor module 422 is electrically connected to the fourth resistor 423 and the second heating module 425 respectively. The third resistor 423 is electrically connected to control terminal 3.

[0030] Specifically, such as Figure 1As shown, the first optical isolation module 411 and the second optical isolation module 421 have terminals 1-2, 4, and 6, respectively. The first resistor 413, the second resistor 414, the third resistor 423, the fourth resistor 424, the first heating module 415, and the second heating module 425 have terminals 1 and 2, respectively. The first thyristor module 412 and the second thyristor module 422 have terminals 1-3, respectively. Terminal 1 of the first optical isolation module 411 and terminal 1 of the second optical isolation module 421 are electrically connected to terminals 2 of the first resistor 413 and the third resistor 423, respectively. Terminals 2 of the first optical isolation module 411 and the second optical isolation module 421 are electrically connected and also electrically connected to the control terminal 3. Terminal 4 of the first optical isolation module 411 is connected to the power supply circuit 1 and terminal 1 of the first thyristor module 412. The first optical isolation module 411 is electrically connected to terminal 4 of the second optical isolation module 411; terminal 6 of the first optical isolation module 411 is electrically connected to terminal 1 of the first resistor 413; terminal 4 of the second optical isolation module 421 is electrically connected to terminal 1 of the first thyristor 412; terminal 6 of the second optical isolation module 421 is electrically connected to terminal 1 of the second resistor 423; terminal 1 of the first resistor 413 is electrically connected to control terminal 3; terminal 2 of the second resistor 414 is electrically connected to terminal 2 of the first thyristor module 412 and terminal 1 of the first heating module 415; terminal 1 of the third resistor 423 is electrically connected to control terminal 3; terminal 2 of the fourth resistor 424 is electrically connected to terminal 2 of the first thyristor and terminal 1 of the second heating module 425; terminal 2 of the first heating module 415 is electrically connected to power circuit 1 and terminal 2 of the second heating module 425.

[0031] When mains power is input into power circuit 1, it supplies power to the first heating module 415 and the second heating module 425. Through rectification by power circuit 1, DC power is output to power control module 21 and control terminal 3. Control module 21 can adjust the output current frequency of power circuit 1 to ensure a stable current output and stable operation. In specific implementation, control signals are sent through control terminal 3 to terminal 1 of the first opto-isolation module 411, causing photodiode U5A within the first opto-isolation module 411 to conduct. Simultaneously, the bidirectional thyristor connected to terminals 4 and 5 within the first opto-isolation module 411 conducts, thereby activating the first thyristor module 412 electrically connected to the first opto-isolation module 411. The first heating module 415 is powered by power circuit 1. When the first thyristor module 412 conducts, the first heating module 415 forms a loop with the photoelectric sensor circuit 1, enabling the first heating module 415 to operate. The first heating module 415 is directly powered by mains electricity and is located on the high-voltage side. Therefore, a first optical isolation module 411 is used to isolate the first heating module 415 from the control terminal 3, preventing the formation of a high-voltage circuit between the control terminal 3 and the first heating module 415 when the operator operates the control terminal 3. Simultaneously, a first thyristor module 412 is used instead of a relay to control the first heating module 415. It should be noted that, since the first thyristor module 412 is a contactless electronic switch, current flowing through either terminal 1 or terminal 2 of the first thyristor module 412 will turn it on. This avoids the need for relay contacts to engage, maintaining better control over the high-voltage side of the first heating module 415. The first resistor 413 and the second resistor 414 serve as current-limiting protection to prevent excessive current from damaging the first optical isolation module 411 and the first thyristor module 412. The working principle of the second optical isolation module 421 and the second SCR module 422 is the same as that of the first optical isolation module 411 and the first SCR module 412, and will not be repeated here. The third resistor 423 and the fourth resistor 424 have the same function as the first resistor 413 and the second resistor 414, and will not be repeated here. In this embodiment, both the first optical isolation module 411 and the second optical isolation module 421 use CT3022 optocouplers.

[0032] Furthermore, such as Figure 1 As shown, the power supply circuit 1 includes a first protection module 11, a first rectifier module 12, and a transformer module 13. The first protection module 11 is electrically connected to the first rectifier module 12 and the heating circuit 4, respectively. The first rectifier module 12 is electrically connected to the transformer module 13, and the transformer module 13 is electrically connected to the control module 21 and the control terminal 3, respectively.

[0033] The first protection module 11 provides current limiting and surge protection for the subsequent first rectifier module 12 and transformer module 13. The first rectifier module 12 is used to rectify the AC power and output the AC power as a DC pulsating voltage, while reducing the differential mode interference in the DC pulsating voltage. The transformer module 13 steps down the DC pulsating voltage and further rectifies it to output DC power to supply power to the control module 21 and the control terminal 3.

[0034] Furthermore, such as Figure 1 As shown, the first protection module 11 includes a first protection component 111 and a first filter component 112. The first protection component 111 is electrically connected to the first filter component 112, the first rectifier module 12, the heating circuit 4, and the mains power.

[0035] Specifically, the protection component 111 includes a fuse F1, a resistor MOV, a resistor RX1, a resistor RX2, and a resistor FR. The first filter component 112 includes a capacitor CX1. The fuse F1, resistor MOV, capacitor CX1, resistor RX1, resistor RX2, and resistor FR each have a terminal 1 and a terminal 2. Terminal 1 of the fuse F1 is electrically connected to the mains power. Terminals 1 and 2 of the resistor MOV, capacitor CX1, resistor RX1, and resistor RX2 are connected in parallel. Terminal 1 of the parallel connection is electrically connected to terminal 2 of the fuse F1 and terminal 1 of the resistor FR. Terminal 2 of the parallel connection is electrically connected to the mains power and the heating circuit. Terminal 2 of the resistor FR is electrically connected to the rectifier module and the heating circuit.

[0036] It should be noted that fuse F1 protects the entire power supply circuit 1. When the AC current input to power supply circuit 1 is too large, fuse F1 will blow to disconnect the entire power supply circuit 1. Resistor MOV prevents the input AC current from generating surge voltage, so as to avoid the surge voltage from causing overvoltage impact on resistors RX1, RX2, FR and capacitor CX1. Resistors RX1, RX2 and FR play a current limiting role to prevent the first rectifier module 12 from being burned out. Capacitor CX1 filters the AC current to prevent differential mode interference of AC current.

[0037] Furthermore, such as Figure 1 The first rectifier module 12 shown includes a bridge rectifier component BD121 and a second filter component 122. The bridge rectifier component BD121 has a positive input terminal and a negative input terminal. The positive input terminal and the negative input terminal of the bridge rectifier component BD121 are electrically connected to the first protection module 11 and the second filter component 122, respectively. The second filter component 122 is electrically connected to the transformer module 13 and is grounded.

[0038] Specifically, the second filter component 122 includes inductors L1 and L2, capacitors EC4 and EC2, each having a terminal 1 and a terminal 2. Terminal 1 of inductor L1 is electrically connected to the positive input terminal of the bridge rectifier BD and terminal 1 of capacitor EC4, while terminal 2 of inductor L1 is electrically connected to terminal 1 of capacitor EC2 and the transformer module. Terminal 1 of inductor L2 is electrically connected to the negative input terminal of the bridge rectifier BD and terminal 2 of capacitor EC4, while terminal 2 of inductor L2 is electrically connected to terminal 2 of capacitor EC4 and the transformer module, and is also grounded. Terminal 1 of capacitor EC4 is electrically connected to the positive input terminal of the bridge rectifier BD, and terminal 2 of capacitor EC4 is electrically connected to the negative input terminal of the bridge rectifier BD. Terminal 1 of capacitor EC2 is electrically connected to the transformer module. Terminal 2 of capacitor EC2 is grounded.

[0039] It should be noted that the AC power is rectified into DC pulsating voltage by the bridge rectifier BD 121, and then filtered by inductors L1 and L2, capacitors EC4 and EC2 to reduce noise in the DC pulsating voltage and prevent noise in the DC pulsating voltage from being input into transformer module 13 and affecting the transformation efficiency of transformer module 13.

[0040] Furthermore, such as Figure 1 As shown, the transformer module 13 includes a second protection component 131, a third filter component 132, a first rectifier component 133, and a transformer T1. The second protection component 131 is electrically connected to the third filter component 132, the first rectifier component 133, the transformer T1, the first rectifier module 12, and the control module 21, respectively. The third filter component 132 is electrically connected to the first rectifier component 133 and the transformer T1, respectively. The first rectifier component 133 is electrically connected to the transformer T1 and the control module 21, respectively. The transformer T1 is electrically connected to the control module 21 and the control terminal 3, respectively.

[0041] Specifically, the second protection component 131 includes resistors R6, R7, R8, R9, R10, and R11; the third filter component includes capacitors C1, C4, and EC1; the first rectifier component 133 includes diodes D1 and D2; the transformer T1 has terminals 1-4, 6, and 7; and resistors R7, R8, R9, R10, R11, C4, EC1, D1, and D2 each have terminal 1 and terminal 2. Terminal 1 of resistor R7 is electrically connected to control module 21; terminal 2 of resistor R7 is electrically connected to terminal 1 of resistor R8; terminal 2 of resistor R8 is electrically connected to the first rectifier module 12; terminals 1 and 2 of capacitor C1, resistor R9, and resistor R11 are connected in parallel, and terminal 1 of the parallel connection is electrically connected to terminal 4 of transformer T1 and terminal 2 of resistor R8 respectively, and terminal 2 of the parallel connection is electrically connected to terminal 1 of resistor R10; terminal 2 of resistor R10 is electrically connected to terminal 2 of diode D2; terminal 1 of diode D2 is electrically connected to control module 21 and... Terminal 3 of transformer T1 is electrically connected; resistor R6 and capacitor C4 are connected in series, terminal 2 of resistor R6 is electrically connected to terminal 1 of capacitor C4, terminal 1 of resistor R6 and terminal 2 of capacitor C4 are connected in parallel to terminals 1 and 2 of diode D1, and terminal 1 of resistor R6 and terminal 2 of capacitor C4 are also electrically connected to terminal 1 of capacitor EC1; terminal 1 of diode D1 is electrically connected to terminal 7 of transformer T1, terminal 2 of diode D1 is electrically connected to terminal 1 of capacitor EC1, and outputs voltage VCC; terminal 2 of capacitor EC1 is grounded.

[0042] It should be noted that, in order to prevent the DC pulsating voltage after AC power conditioning from being too large, resistors R7 and R8 are used to divide the voltage to prevent damage to control module 21. Capacitor C1 filters the DC pulsating voltage. The functions of resistors R6, R9, R10 and R11 are the same as those of resistors RX1 and RX2, and will not be repeated here. Capacitors C4 and EC1 filter the DC pulsating voltage after transformer T1 step-down, reducing the noise output to control terminal 3 and control module 21, making the operation of control terminal 3 and control module 21 more stable.

[0043] Furthermore, such as Figure 1 As shown, the transformer module 13 also includes a withstand voltage component 134, which is electrically connected to the third filter component 132 and the transformer module 13 respectively.

[0044] Specifically, the withstand voltage component 134 includes capacitor CY1 and capacitor CY2. Capacitor CY1 and capacitor CY2 have terminal 1 and terminal 2. Terminal 1 of capacitor CY1 is grounded. Terminal 2 of capacitor CY1 is electrically connected to terminal 1 of capacitor CY2. Terminal 2 of capacitor CY2 is electrically connected to terminal 1 of transformer T1. Both terminal 2 of capacitor CY2 and terminal 1 of transformer T1 are grounded.

[0045] It should be noted that capacitors CY1 and CY2 are Y capacitors to prevent common-mode interference in the circuit and reduce EMI (electromagnetic interference) of the output voltage VCC.

[0046] Furthermore, such as Figure 1 As shown, the control module 21 includes a control chip 211, a third protection component 212, a fourth filter component 213, and a second rectifier component 214. The control chip 211 has terminals 1-8. Terminal 1 of the control chip 211 is electrically connected to the third protection component 212 and the fourth filter component 213, respectively. Terminal 2 of the control chip 211 is electrically connected to the third protection component 212 and the fourth filter component 213, and terminal 2 of the control chip 211 is grounded. Terminal 3 of the control chip 211 is electrically connected to the third protection component 212 and the fourth filter component 213, respectively. Terminal 4 of the control chip 211 is electrically connected to the third protection component 212. Terminals 5-8 of the control chip 211 are electrically connected to the power supply circuit 1.

[0047] Specifically, the third protection component 212 includes resistors R11, R12, R13, R14 and R15, the fourth filter component 213 includes capacitors C6 and EC3, and the second rectifier component 214 includes diode D3. Resistors R11, R12, R13, R14 and R15, capacitors C6 and EC3 and diode D3 each have terminal 1 and terminal 2. Terminal 1 of resistor R11 is electrically connected to terminal 1 of control chip 211, terminal 1 of capacitor EC3, and power supply circuit 1, respectively. Terminal 2 of resistor R11 is electrically connected to terminal 1 of diode D3. Terminal 1 of resistor R12 is electrically connected to terminal 2 of resistor R15, terminal 2 of capacitor C6, and terminal 3 of control chip 211, respectively. Terminal 2 of resistor R12 is electrically connected to terminal 2 of diode D2 and terminal 2 of transformer T1, respectively. Terminals 1 of resistors R13 and R14 are electrically connected to terminal 4 of control chip 211, and terminals 2 of resistors R13 and R14 are grounded. Terminals 1 of resistor R15 and terminal 1 of capacitor C6 are connected in parallel, and terminals 2 of resistor R15 and terminal 2 of capacitor C6 are connected in parallel. Terminal 1 of the parallel connection is electrically connected to terminal 2 of control chip 211, and terminal 2 of the parallel connection is electrically connected to terminal 3 of control chip 211. Terminal 2 of capacitor EC3 is grounded.

[0048] It should be noted that terminal 1 of control chip 211 is the power supply terminal. Resistors R7 and R8 provide the startup voltage for control chip 211. After control chip 211 starts up, terminal 2 of transformer T1 will supply power to terminal 1 of control chip 2, and diode D3 will rectify the current input to terminal 2 of transformer T1. Resistor R11 is used for current limiting protection, and capacitor EC3 is used to filter the current input to terminal 2 of transformer T1. Terminal 2 of control chip 211 is ground, and terminal 3 of control chip 211 is a feedback pin. Resistor R15 and capacitor C6 are connected in parallel between terminals 2 and 3 of control chip 211. By inputting the PWM duty cycle, control chip 211 performs loop regulation, thereby making its operation more stable. Terminal 4 of control chip 211 is a current detection terminal. By sampling and detecting resistors R13 and R14, excessive current is prevented from being input to the control chip. Terminals 5-8 of control chip 211 are control pins and are electrically connected to terminal 3 of transformer T1. By outputting control signals through terminals 5-8 of control chip 211, the frequency of transformer T1 can be adjusted, thereby adjusting the output voltage of the transformer. In this embodiment, the control chip is the LY6023A22 main control chip.

[0049] Furthermore, such as Figure 1 As shown, the control terminal 3 includes a control component 31 and a voltage regulator module 32. The control component 31 is electrically connected to the voltage regulator module 32, the first heating module 415, the second heating module 425, and the power supply circuit 1, respectively. The voltage regulator module 32 is electrically connected to the heating circuit 4.

[0050] It should be noted that the control component 31 controls the operation of the first heating module 415 and the second heating module 425. In order to prevent fluctuations in the control signal sent by the control component 31, the voltage regulator module 32 is used to reduce the fluctuations in the control signal, so that the control component 31 can output a stable control signal.

[0051] Furthermore, such as Figure 1 As shown, the voltage regulator module 32 includes a fourth protection component 321, a fifth filter component 322, and a linear voltage regulator component 323. The linear voltage regulator component 323 is electrically connected to the fourth protection component 321, the fifth filter component 322, the control component 31, and the heating circuit 4, and is grounded. The fourth protection component is electrically connected to the fifth filter component 322 and the control component 31, respectively. The fifth filter component 322 is electrically connected to the heating circuit 4, and is grounded.

[0052] Specifically, the control component 31 has five ports: VCC, VCS, HOT1, HOT2, and GND; the linear regulator component 323 has three ports: VIN, VOUT, and GND; the fourth protection component 321 includes a resistor R1; and the fifth filter component 322 includes capacitors C2 and C3. Resistor R1, capacitor C2, and capacitor C3 each have terminals 1 and 2, respectively. The VCC terminal of the control component 31 is electrically connected to terminal 1 of resistor R1, and the VCS terminal of the control component 31 is electrically connected to the VIN terminal of the linear regulator component 323. The OUT terminal and terminal 1 of capacitor C2 are electrically connected respectively. The HOT1 and HOT2 terminals of control component 31 are electrically connected to the first heating module 415 and the second heating module 425 respectively. The GND of control component 31 is grounded. Terminal 2 of resistor R1 is electrically connected to terminal 1 of capacitor C3 and the VIN terminal of linear voltage regulator component 323. Terminal 1 of capacitor C3 is electrically connected to the VOUT terminal of linear voltage regulator component 323. Terminals 2 of capacitor C2 and 2 of capacitor C3 are grounded.

[0053] It should be noted that the control signal sent from the VCC terminal of the control component 31 to the VIN terminal of the linear voltage regulator 323 is input to prevent fluctuations in the control signals input to the first heating module 415 and the second heating module 425. The resistor R1 performs circuit protection and current limiting, and the capacitors C2 and C3 filter the control signal sent from the VCC terminal of the control component 31.

[0054] In summary, in the specific implementation of this utility model, the AC mains input is filtered by capacitor CX1 and then rectified into a DC pulsating voltage by bridge rectifier BD121. The control chip 211 is activated through resistors R7 and R8. The DC pulsating voltage is then filtered by inductors L1 and L2, capacitors EC4 and EC2 to prevent noise from being input to terminals 1-4 of transformer T1. At the same time, terminals 1 and 2 of transformer T1 step down the DC pulsating voltage to supply power to control chip 211. Control chip 211 can then adjust the operating frequency of transformer T1, thereby adjusting the output voltage of transformer T1.

[0055] After the transformer T1 steps down the voltage, the output voltage VCC supplies power to the control component 31. The control component 31 sends control signals to the first optical isolation module 411 or the second optical isolation module 421 through the two ports HOT1 and HOT2. After the first optical isolation module 411 or the second optical isolation module 421 is turned on, the first thyristor module 412 or the second thyristor module 422 is also turned on, thereby controlling the first heating module 415 or the second heating module 425 to work.

[0056] Thus, by adjusting the operating frequency of transformer T1 through control chip 211, the output voltage of transformer T1 is adjusted, preventing the components inside the isolation power supply from being damaged. At the same time, the first thyristor module 412 and the second thyristor module 422 replace the relay, preventing a decrease in the control capability of the first heating module 415 or the second heating module 425.

[0057] The above are merely embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. An electric heating wire heating control circuit, characterized by comprising: The utility model relates to a kind of heating circuit, including: power supply circuit (1), control circuit (2), control end (3), heating circuit (4) are electrically connected respectively, power supply circuit (1) is connected with control circuit (2), control end (3) and heating circuit (4) respectively with control circuit (2), control end (3) and heating circuit (4) are electrically connected, control circuit (2) includes control module (21), control module (21) is electrically connected with power supply circuit (1), control end (3) is electrically connected with heating circuit (4), heating circuit (4) includes first working module (41) and second working module (42), first working module (41) includes first optical isolation module (411), first thyristor module (412), first resistance (413), second resistance (414) and first heating module (415);Second working module (42) includes second optical isolation module (421), second thyristor module (422), third resistance (423), fourth resistance (424) and second heating module (425), first optical isolation module (411) is electrically connected with first thyristor module (412), first resistance (413), second resistance (414), control end (3) and power supply circuit (1) respectively, first thyristor module (412) is electrically connected with second resistance (413), first heating module (415) second optical isolation module (421), second thyristor module (422), power supply circuit (1) and respectively, first resistance (413) is electrically connected with control end (3), first heating module (415) is electrically connected with power supply circuit (1) and second heating module (425) respectively;Second optical isolation module (421) is electrically connected with second thyristor module (422), third resistance (423), fourth resistance (424) and control end (3) respectively, second thyristor module (422) is electrically connected with fourth resistance (423) and second heating module (425) respectively, third resistance (423) is electrically connected with control end (3). Power supply circuit (1) includes first protection module (11), first rectifier module (12) and transformer module (13), first protection module (11) is electrically connected with first rectifier module (12) and heating circuit (4) respectively, first rectifier module (12) is electrically connected with transformer module (13), and transformer module (13) is electrically connected with control module (21) and control end (3) respectively.

2. The glow wire heating control circuit of claim 1, wherein, First protection module (11) includes first protection component (111) and first filter component (112), and the first protection component (111) is electrically connected with the first filter component (112), the first rectifier module (12), the heating circuit (4) and the commercial power respectively.

3. The glow wire heating control circuit of claim 2, wherein, The first rectifier module (12) includes bridge rectifier component BD (121) and second filter component (122), and the bridge rectifier component BD (121) has a positive input end and a negative input end, and the positive input end and the negative input end of the bridge rectifier component BD (121) are electrically connected with the first protection module (11) and the second filter component (122) respectively, the second filter component (122) is electrically connected with the transformer module (13), and the second filter component (122) is grounded.

4. The glow wire heating control circuit of claim 2, wherein, ​ 5. The glow wire heating control circuit of claim 2, wherein, The transformer module (13) comprises a second protection component (131), a third filter component (132), a first rectification component (133) and a transformer T1, the second protection component (131) is electrically connected with the third filter component (132), the first rectification component (133), the transformer T1, the first rectification module (12) and the control module (21) respectively, the third filter component (132) is electrically connected with the first rectification component (133) and the transformer T1 respectively, the first rectification component (133) is electrically connected with the transformer T1 and the control module (21) respectively, and the transformer T1 is electrically connected with the control module (21) and the control end (3) respectively.

6. The glow wire heating control circuit of claim 5, wherein, The transformer module (13) further comprises a voltage resistance component (134), and the voltage resistance component (134) is electrically connected with the third filter component (132) and the transformer module (13) respectively.

7. The glow wire heating control circuit of claim 1, wherein, The control module (21) comprises a control chip (211), a third protection component (212), a fourth filter component (213) and a second rectification component (214), the control chip (211) has 1-8th ends, the 1st end of the control chip (211) is electrically connected with the third protection component (212) and the fourth filter component (213) respectively, the 2nd end of the control chip (211) is electrically connected with the third protection component (212) and the fourth filter component (213) respectively, and the 2nd end of the control chip (211) is grounded, the 3rd end of the control chip (211) is electrically connected with the third protection component (212) and the fourth filter component (213) respectively, the 4th end of the control chip (211) is electrically connected with the third protection component (212), and the 5th-8th ends of the control chip (211) are electrically connected with the power supply circuit (1).

8. The glow wire heating control circuit of claim 1, wherein, The control end (3) comprises a control component (31) and a voltage stabilizing module (32), the control component (31) is electrically connected with the voltage stabilizing module (32), the first heating module (415), the second heating module (425) and the power supply circuit (1) respectively, and the voltage stabilizing module (32) is electrically connected with the heating circuit (4).

9. The glow wire heating control circuit of claim 8, wherein, The voltage stabilizing module (32) comprises a linear voltage stabilizing component (323), a fourth protection component (321) and a fifth filter component (322), the linear voltage stabilizing component (323) is electrically connected with the fourth protection component (321), the fifth filter component (322), the control component (31) and the heating circuit (4) respectively, and the linear voltage stabilizing component (323) is grounded, the fourth protection component is electrically connected with the fifth filter component (322) and the control component (31) respectively, the fifth filter component (322) is electrically connected with the heating circuit (4), and the fifth filter component (322) is grounded.

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