Secondary protection circuit of toaster

Abstract

The utility model relates to a secondary protection circuit of a toaster. The secondary protection circuit comprises a power supply module, a fusing device and a control circuit, the power supply module comprises an alternating current power supply and a main switch; the main switch comprises a first electric control switch and a second electric control switch; the fusing device is connected in series between the first electric control switch and the toaster furnace pipe heating wire and is used for fusing when the flowing current is higher than the rated current; the second electric control switch is connected with a toaster furnace pipe heating wire to form a loop; the first end of the control circuit is connected with the main switch and is used for controlling the main switch to be in a closed state when the preset time is not reached and controlling the main switch to be in an open state when the preset time is reached; the second end of the control circuit is connected with the two ends of the toaster furnace pipe heating wire and used for controlling the fusing device to fuse when the preset time is up and the main switch is not switched off, and the purpose of secondary protection is achieved. Therefore, a normal timing operation function and a secondary protection function are realized, and the circuit is simpler and smaller in size.

Description

Technical Field

[0001] The utility model relates to the technical field of household appliances, in particular to a secondary protection circuit of a toaster. Background Art

[0002] At present, the laws and regulations related to toasters are gradually updated and upgraded, requiring the addition of a secondary protection function, which can automatically disconnect the heating wire circuit in the event of abnormal failure of the main control switch circuit, thereby eliminating fire hazards.

[0003] The secondary protection technology provided by existing products on the market generally requires the addition of independent power circuits, timing control and circuit breaker relays, which imposes many restrictions on the cost, volume and structural design of the toaster control circuit board. Utility Model Content

[0004] In view of this, an object of the present invention is to provide a toaster secondary protection circuit, which can solve the technical problems of complex circuits and structural limitations in the prior art for toaster secondary protection.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] According to a first aspect of the present invention, a toaster secondary protection circuit is provided, comprising a power module, a fuse device, and a control circuit;

[0007] The power module includes an AC power supply and a main switch, the main switch includes a first electronically controlled switch and a second electronically controlled switch, the first electronically controlled switch is connected in series to the live wire of the AC power supply, and the second electronically controlled switch is connected in series to the neutral wire of the AC power supply;

[0008] The fuse device is connected in series between the first electronically controlled switch and the heating wire of the toaster furnace, and is used to fuse when the current flowing through it exceeds the rated current; the second electronically controlled switch is connected to the heating wire of the toaster furnace to form a loop;

[0009] The first end of the control circuit is connected to the main switch, and is used to control the main switch to be in a closed state before the preset time is reached, and to control the main switch to be in an open state when the preset time is reached;

[0010] The second end of the control circuit is respectively connected to the two ends of the heating wire of the toaster furnace, and is used to control the fuse device to fuse when the preset time is reached and the main switch is not disconnected, thereby achieving the purpose of secondary protection.

[0011] Optionally, the control circuit includes: a controller, a first timing drive circuit;

[0012] The first timing drive circuit includes a first drive and an electromagnet;

[0013] The first driver is connected to the controller and the electromagnet respectively; the electromagnet is connected to the main switch;

[0014] The controller is configured to send a first timing signal to the first driver when the preset time has not yet arrived; the first driver is configured to amplify the first timing signal and then drive the electromagnet to attract, so as to maintain the main switch in a closed state;

[0015] The controller is further configured to cancel the first timing signal sent to the first driver when a preset time is reached; the first driver is configured to drive the electromagnet to close, so that the main switch is disconnected.

[0016] Optionally, the control circuit further includes: a second timing drive circuit;

[0017] The second timing drive circuit includes a second drive and a thyristor;

[0018] The second driver is connected to the controller and the thyristor respectively; the thyristor is connected to both ends of the heating wire of the toaster furnace;

[0019] The controller is used to send a second timing signal to the second driver when a preset time is reached and the main switch is not disconnected; the second driver is used to amplify the second timing signal and drive the thyristor to turn on; the thyristor is used to make the current flowing through the fuse device higher than the rated current after being connected to the power supply and turned on.

[0020] Optionally, the 12V power supply includes a diode D3, a resistor R11 and an electrolytic capacitor EC2;

[0021] The diode D3, the resistor R11 and the electrolytic capacitor EC2 form a half-wave rectifier circuit for converting the AC voltage tapped from the toaster heating element HEAT1 into a DC 12V voltage;

[0022] The 5V1 power supply includes an integrated circuit U2, an electrolytic capacitor EC1 and a diode D4;

[0023] The integrated circuit U2, the electrolytic capacitor EC1 and the diode D4 form a series voltage stabilizing circuit for converting a DC 12V voltage into a DC 5V1 voltage.

[0024] Optionally, the controller includes an integrated circuit U1;

[0025] The PA0 pin of the integrated circuit U1 is connected to the first driver, and is used to output / withdraw the first timing signal to the first driver;

[0026] The PA1 pin of the integrated circuit U1 is connected to the second driver, and is used to output the second timing signal to the second driver.

[0027] Optionally, the first driver includes a transistor Q2, a resistor R8 and a diode D2;

[0028] The first end of the resistor R8 is connected to the pin end of PA0, and the second end is connected to the base of the transistor Q2;

[0029] The collector of the transistor Q2 is connected to the anode of the diode D2, and the emitter is grounded; the electromagnet is connected to both ends of the diode D2.

[0030] Optionally, the second driver shown includes a resistor R1, a resistor R2, a resistor R5 and capacitors C1 to C3;

[0031] The first end of the resistor R5 is connected to the pin end of PA1, and the second end is respectively connected to the first end of the resistor R1, the first end of the resistor R2, the first end of the capacitor C1 and the control electrode of the thyristor;

[0032] The second end of the resistor R2 is connected to the first end of the capacitor C2 and the first end of the capacitor C3 respectively;

[0033] The second anode of the thyristor is connected to the second end of the capacitor C2 and the second end of the capacitor C3 respectively, and is connected to the live wire output;

[0034] The first anode of the thyristor is connected to the second end of the capacitor C1 and the first end of the resistor R1 respectively, and is grounded.

[0035] Optionally, the controller further includes capacitors C4-C5, a resistor R7 and a thermistor RT1;

[0036] A first end of the capacitor C4 is connected to the VDD pin of the integrated circuit U1, a second end is connected to the VSS pin of the integrated circuit U1, and is grounded;

[0037] The first end of the capacitor C5 is respectively connected to the PB2 pin of the integrated circuit U1, the first end of the resistor R7 and the second end of the thermistor RT1, and the second end is respectively connected to the first end of the thermistor RT1 and grounded;

[0038] The second end of the resistor R7 is connected to the 5V1 power supply.

[0039] Optionally, the controller further includes a button SW1 and an adjustable potentiometer VER1;

[0040] The second pin of the adjustable potentiometer VER1 is connected to the PA2 pin of the integrated circuit U1; the third and fourth pins are connected to the 5V1 power supply respectively; the first and fifth pins are grounded;

[0041] The first end of the button SW1 is connected to the second end of the resistor R8 , and the second end is respectively connected to the negative electrode of the electrolytic capacitor EC1 and the second pin of the integrated circuit U2 , and is grounded.

[0042] The above one or more technical solutions provided by the present invention may have the following advantages or at least achieve the following technical effects:

[0043] The utility model proposes a secondary protection circuit for a toaster, comprising a power module, a fuse device, and a control circuit; the power module includes an AC power supply and a main switch, the main switch includes a first electrically controlled switch and a second electrically controlled switch, the first electrically controlled switch being connected in series to the live wire of the AC power supply, and the second electrically controlled switch being connected in series to the neutral wire of the AC power supply; the fuse device being connected in series between the first electrically controlled switch and the heating wire of the toaster furnace, and being configured to fuse when the current flowing therethrough exceeds the rated current; the second electrically controlled switch being connected to the heating wire of the toaster furnace, forming a loop; a first end of the control circuit being connected to the main switch, and being configured to control the main switch to be in a closed state before a preset time is reached, and to control the main switch to be in an open state when a preset time is reached; a second end of the control circuit being connected to both ends of the heating wire of the toaster furnace, and being configured to control the fuse device to fuse when the preset time is reached and the main switch is not disconnected, thereby achieving the purpose of secondary protection. The technical solution of the present application is to add a fuse device to the circuit so that when the heating wire of the toaster furnace cannot be disconnected due to circuit or mechanical reasons, the control circuit triggers the fuse device to operate, and the fuse is disconnected from the power supply, thereby eliminating the safety hazards of the toaster being powered on for a long time to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 This is the principle diagram of the secondary protection circuit of the toaster proposed in this utility model;

[0046] Figure 2 This is a module diagram of the secondary protection circuit of the toaster proposed in the present invention;

[0047] Figure 3This is the heating wire wiring circuit diagram proposed by the utility model;

[0048] Figure 4 This is the circuit diagram of the control board proposed in this utility model;

[0049] Figure 5 This is the circuit diagram of the power board proposed by the utility model.

[0050] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0051] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0052] It should be noted that, in this utility model, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a device or system comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such device or system. Without further limitation, the phrase "comprise..." does not preclude the presence of other identical elements in the device or system comprising such elements. In this utility model, unless otherwise expressly specified or limited, the terms "connect," "fix," and the like should be interpreted broadly. For example, "connect" can mean a fixed connection, a removable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediary; internal communication between two elements or an interaction between two elements. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances. Furthermore, the technical solutions of the various embodiments may be combined with each other, but only if they are achievable by those skilled in the art. If a combination of technical solutions contradicts or cannot be implemented, such combination shall be deemed non-existent and outside the scope of protection claimed by this utility model.

[0053] When the toaster control circuit times out or is abnormal, the furnace heating wire continues to be energized. In order to eliminate the safety hazard of long-term power-on, the utility model provides a toaster secondary protection circuit. The specific embodiments and implementation methods are as follows:

[0054] Reference Figure 1 , Figure 1 This is the principle diagram of the secondary protection circuit of the toaster proposed in this utility model. The secondary protection circuit of the toaster may include: power module 01, fuse device 03, control circuit 02;

[0055] The fuse device 03 is connected in series between the power module 01 and the load 04 (the heating wire of the toaster furnace). The fuse device 03 is controlled by the control circuit 02. There are two specific working conditions:

[0056] Normal working condition: Fuse device 03 does not operate, and control circuit 02 normally disconnects load 04 after the preset time is reached;

[0057] Secondary protection working condition: When the preset time is reached and the load 04 is still not disconnected, the control circuit 02 triggers the fuse device 03 to operate, the fuse melts, and the connection with the power module 01 is cut off.

[0058] To achieve the above operations, refer to Figure 2 , Figure 2 This is a module diagram of the secondary protection circuit of the toaster proposed by the present invention.

[0059] The power module 01 includes an AC power supply 01-3 and a main switch 01-4. The main switch 01-4 includes a first electronically controlled switch S1 and a second electronically controlled switch S2. The first electronically controlled switch S1 is connected in series to the live wire L of the AC power supply 01-3, and the second electronically controlled switch S2 is connected in series to the neutral wire N of the AC power supply 01-3. A fuse device 03 is connected in series between the first electronically controlled switch S1 and the load 04 (the toaster furnace heating wire) and is configured to fuse when the current flowing through it exceeds the rated current. The second electronically controlled switch S2S2 is connected to the toaster furnace heating wire 04 to form a loop. A first end of the control circuit 02 is connected to the main switch 01-4 and is configured to control the main switch 01-4 to be in a closed state before the preset time is reached, and to control the main switch 01-4 to be in an open state when the preset time is reached. A second end of the control circuit 02 is connected to both ends of the toaster furnace heating wire 04 and is configured to control the fuse device 03 to fuse when the preset time is reached and the main switch 01-4 is not disconnected, thereby achieving the purpose of secondary protection.

[0060] Furthermore, the control circuit 02 may further include: a controller 02 - 1 and a first timing driving circuit.

[0061] Among them, the first timing drive circuit includes a first driver 02-2 and an electromagnet 02-3; the first driver 02-2 is connected to the controller 02-1 and the electromagnet 02-3 respectively; the electromagnet 02-3 is connected to the main switch 01-4; the controller 02-1 is used to send a first timing signal to the first driver 02-2 when the preset time has not been reached; the first driver is used to amplify the first timing signal and drive the electromagnet 02-3 to attract to maintain the main switch 01-4 in a closed state; the controller 02-1 is also used to cancel the first timing signal sent to the first driver 02-2 when the preset time is reached; the first driver 02-2 is used to drive the electromagnet 02-3 to turn off, so that the main switch 01-4 is disconnected.

[0062] Furthermore, the control circuit 02 further includes: a second timing drive circuit.

[0063] Wherein, the second timing drive circuit includes a second drive 02-4 and a thyristor 02-5;

[0064] The second driver 02-4 is connected to the controller 02-1 and the thyristor 02-5 respectively; the thyristor 02-5 is connected to both ends of the toaster furnace heating wire 04;

[0065] The controller 02-1 is used to send a second timing signal to the second driver 02-4 when the preset time is reached and the main switch is not disconnected; the second driver 02-4 is used to drive the thyristor 02-5 to turn on with the second timing signal; and the thyristor 02-5 is used to make the current flowing through the fuse device 03 higher than the rated current after being connected to the power supply and turned on.

[0066] Furthermore, in an embodiment of the present invention, the power supply module 01 may also include a 5V1 power supply 01-2 and a 12V power supply 01-1; the 5V1 power supply 01-2 is respectively connected to the controller 02-1 and the 12V power supply 01-1; the 12V power supply 01-1 is respectively connected to the 5V1 power supply 01-2, the electromagnet 02-3, the thyristor 02-5 and the toaster furnace heating wire 04.

[0067] Based on the functions and connections of the above modules, the following two working situations are realized:

[0068] Normal operation: AC power source 01-3 is connected normally. When the user presses main switch 01-4, load 04 is connected to AC power source 01-3 through fuse 03 and main switch 01-4 and begins operating. Simultaneously, 12V power supply 01-1 and 5V1 power supply 01-2 are powered on, providing appropriate voltage for the entire control circuit. Controller 02-1 begins operation, issuing a first timing signal, which is amplified by first driver 02-2 and then drives electromagnet 02-3 to close, maintaining the closed state of main switch 01-4. When the preset timer expires, controller 02-1 removes the first timing signal, immediately turning off first driver 02-2 and electromagnet 02-3, and main switch 01-4 disconnects from the power supply and ceases operation.

[0069] Secondary protection operates as follows: When the preset timer expires but main switch 01-4 has not yet opened, controller 02-1 triggers a second timing signal, which is amplified by second driver 02-4, turning on thyristor 02-5. It is understood that fuse device 03 is connected in series between the power input and load 04, and thyristor 02-5 is connected in parallel with load 04. According to circuit principles, the current flowing through fuse device 03 is equal to the sum of the current flowing through load 04 and the current flowing through thyristor 02-5. Under normal operating conditions, thyristor 02-5 is non-conductive and no current flows. The current flowing through fuse device 03 is equal to the current flowing through load 04. In actual applications, by selecting appropriate component parameters, the current flowing through fuse device 03 does not cause it to melt. However, when thyristor 02-5 is connected to the power supply and turns on, the current flowing through fuse device 03 exceeds its rated value, causing fuse device 03 to self-destruct and melt in a very short time. As a result, thyristor 02-5 and load 04 are disconnected from the power supply, achieving the secondary protection purpose.

[0070] In an alternative embodiment, if Figures 3-5 The figures show the heating wire connection circuit diagram, the control board circuit diagram and the power board circuit diagram of the secondary protection circuit of the toaster proposed by the present invention.

[0071] The HEAT1 tap of the toaster furnace heating wire 04 is connected to the 12V power supply 01-1. In the power board circuit diagram, as key secondary protection components, F1 is the fuse device 03 and Q1 is the thyristor 02-5.

[0072] Specifically, the 12V power supply includes a diode D3, a resistor R11, and an electrolytic capacitor EC2; the diode D3, the resistor R11, and the electrolytic capacitor EC2 form a half-wave rectifier circuit for converting the AC voltage tapped from the toaster heater HEAT1 into a DC 12V voltage; the 5V1 power supply includes an integrated circuit U2, a diode D4, and an electrolytic capacitor EC1; the integrated circuit U2, the diode D4, and the electrolytic capacitor EC1 form a voltage stabilizing circuit for converting the DC 12V voltage into a DC 5V1 voltage. It is understood that both the DC 12V voltage and the DC 5V1 voltage are used by the control circuit 02.

[0073] In the control board circuit diagram, controller 02-1 includes integrated circuit U1. Pin PA0 of integrated circuit U1 is connected to first driver 02-2, for outputting / withdrawing a first timing signal to it. Pin PA1 of integrated circuit U1 is connected to second driver 02-4, for outputting a second timing signal to it. It can be understood that integrated circuit U1 generates two timing signals: the first timing signal, used in normal operation, is output via pin PA0 of integrated circuit U1, controlling the engagement and release of electromagnet 02-3. The second timing signal, used for secondary protection, is output via pin PA1 of U1, triggering thyristor Q1 to conduct, thereby triggering the self-destruction of fuse F1. It should be noted that the duration of the first timing signal is shorter than the time required for the second timing signal to trigger, ensuring that the secondary protection is triggered under normal operation.

[0074] Furthermore, the first driver 02-2 may include a transistor Q2, a resistor R8 and a diode D2; the first end of the resistor R8 is connected to the PA0 pin, and the second end is connected to the base of the transistor Q2; the collector of the transistor Q2 is connected to the anode of the diode D2, and the emitter is grounded; the electromagnet is connected to both ends of the diode D2, and when powered on, it attracts the main switch 01-4 and maintains it.

[0075] Furthermore, the second driver 02-4 shown includes resistor R1, resistor R2, resistor R5 and capacitors C1, capacitor C2, and capacitor C3; the first end of resistor R5 is connected to the PA1 pin end, and the second end is respectively connected to the first end of resistor R1, the first end of resistor R2, the first end of capacitor C1, and the control electrode of thyristor Q1; the second end of resistor R2 is respectively connected to the first end of capacitor C2 and the first end of capacitor C3; the second anode of thyristor Q1 is respectively connected to the second end of capacitor C2 and the second end of capacitor C3, and is connected to the live wire output; the first anode of thyristor Q1 is respectively connected to the second end of capacitor C1 and the first end of resistor R1, and is grounded.

[0076] Furthermore, the controller also includes capacitors C4~C5, a resistor R7 and a thermistor RT1; the first end of the capacitor C4 is connected to the VDD pin of the integrated circuit U1, and the second end is connected to the VSS pin of the integrated circuit U1 and grounded; the first end of the capacitor C5 is respectively connected to the PB2 pin of the integrated circuit U1, the first end of the resistor R7 and the second end of the thermistor RT1, and the second end is respectively connected to the first end of the thermistor RT1 and grounded; the second end of the resistor R7 is connected to the 5V1 power supply.

[0077] Furthermore, the controller also includes a button SW1 and an adjustable potentiometer VER1; the second pin of the adjustable potentiometer VER1 is connected to the PA2 pin of the integrated circuit U1, the third and fourth pins are respectively connected to the 5V1 power supply, and the first and fifth pins are grounded; the first end of the button SW1 is connected to the second end of the resistor R8, and the second end is respectively connected to the negative electrode of the electrolytic capacitor EC1 and the second pin of the integrated circuit U2, and is grounded.

[0078] The toaster secondary protection circuit provided in this application can automatically disconnect the heating wire circuit in the event of an abnormal failure of the main control switch circuit, thereby eliminating fire hazards. Only one controller is used to send two timing signals to achieve normal timing operation and secondary protection functions. The secondary protection function is implemented by a circuit composed of key components thyristors, fuses, and peripheral parts. Once triggered, the fuse causes an overcurrent to melt and cannot be restored. After the fuse blows, the load is disconnected from the power supply, making the circuit simpler and smaller in size.

[0079] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

[0080] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0081] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that 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 specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0082] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A toaster secondary protection circuit, characterized in that: Including power module, fuse device, control circuit; The power module includes an AC power supply and a main switch, the main switch includes a first electronically controlled switch and a second electronically controlled switch, the first electronically controlled switch is connected in series to the live wire of the AC power supply, and the second electronically controlled switch is connected in series to the neutral wire of the AC power supply; The fuse device is connected in series between the first electronically controlled switch and the heating wire of the toaster furnace, and is used to fuse when the current flowing through it exceeds the rated current; the second electronically controlled switch is connected to the heating wire of the toaster furnace to form a loop; The first end of the control circuit is connected to the main switch, and is used to control the main switch to be in a closed state before the preset time is reached, and to control the main switch to be in an open state when the preset time is reached; The second end of the control circuit is respectively connected to the two ends of the heating wire of the toaster furnace, and is used to control the fuse device to fuse when the preset time is reached and the main switch is not disconnected, thereby achieving the purpose of secondary protection.

2. The toaster secondary protection circuit according to claim 1, characterized in that: The control circuit includes: a controller, a first timing drive circuit; The first timing drive circuit includes a first drive and an electromagnet; The first driver is connected to the controller and the electromagnet respectively; the electromagnet is connected to the main switch; The controller is configured to send a first timing signal to the first driver when the preset time has not yet arrived; the first driver is configured to amplify the first timing signal and then drive the electromagnet to attract, so as to maintain the main switch in a closed state; The controller is further configured to cancel the first timing signal sent to the first driver when a preset time is reached; the first driver is configured to drive the electromagnet to close, so that the main switch is disconnected.

3. The toaster secondary protection circuit according to claim 2, characterized in that: The control circuit further includes: a second timing drive circuit; The second timing drive circuit includes a second drive and a thyristor; The second driver is connected to the controller and the thyristor respectively; the thyristor is connected to both ends of the heating wire of the toaster furnace; The controller is used to send a second timing signal to the second driver when a preset time is reached and the main switch is not disconnected; the second driver is used to amplify the second timing signal and drive the thyristor to turn on; the thyristor is used to make the current flowing through the fuse device higher than the rated current after being connected to the power supply and turned on.

4. The toaster secondary protection circuit according to claim 3, characterized in that: The power supply module also includes a 5V1 power supply and a 12V power supply; The 5V1 power supply is connected to the controller and the 12V power supply respectively; The 12V power supply is connected to the 5V1 power supply, the electromagnet, the thyristor and the toaster furnace heating wire respectively.

5. The toaster secondary protection circuit according to claim 4, characterized in that: The 12V power supply includes a diode D3, a resistor R11 and an electrolytic capacitor EC2; The diode D3, the resistor R11 and the electrolytic capacitor EC2 form a half-wave rectifier circuit for converting the AC voltage tapped from the toaster heating element HEAT1 into a DC 12V voltage; The 5V1 power supply includes an integrated circuit U2, an electrolytic capacitor EC1 and a diode D4; The integrated circuit U2, the electrolytic capacitor EC1 and the diode D4 form a series voltage stabilizing circuit for converting a DC 12V voltage into a DC 5V1 voltage.

6. The toaster secondary protection circuit according to claim 5, characterized in that: The controller includes an integrated circuit U1; The PA0 pin of the integrated circuit U1 is connected to the first driver, and is used to output / withdraw the first timing signal to the first driver; The PA1 pin of the integrated circuit U1 is connected to the second driver, and is used to output the second timing signal to the second driver.

7. The toaster secondary protection circuit according to claim 6, characterized in that: The first driver includes a transistor Q2, a resistor R8 and a diode D2; The first end of the resistor R8 is connected to the pin end of PA0, and the second end is connected to the base of the transistor Q2; The collector of the transistor Q2 is connected to the anode of the diode D2, and the emitter is grounded; the electromagnet is connected to both ends of the diode D2.

8. The toaster secondary protection circuit according to claim 6, characterized in that: The second driver shown includes a resistor R1, a resistor R2, a resistor R5 and capacitors C1 to C3; The first end of the resistor R5 is connected to the pin end of PA1, and the second end is respectively connected to the first end of the resistor R1, the first end of the resistor R2, the first end of the capacitor C1 and the control electrode of the thyristor; The second end of the resistor R2 is connected to the first end of the capacitor C2 and the first end of the capacitor C3 respectively; The second anode of the thyristor is connected to the second end of the capacitor C2 and the second end of the capacitor C3 respectively, and is connected to the live wire output; The first anode of the thyristor is connected to the second end of the capacitor C1 and the first end of the resistor R1 respectively, and is grounded.

9. The toaster secondary protection circuit according to claim 6, characterized in that: The controller also includes capacitors C4-C5, a resistor R7 and a thermistor RT1; A first end of the capacitor C4 is connected to the VDD pin of the integrated circuit U1, a second end is connected to the VSS pin of the integrated circuit U1, and is grounded; The first end of the capacitor C5 is respectively connected to the PB2 pin of the integrated circuit U1, the first end of the resistor R7 and the second end of the thermistor RT1, and the second end is respectively connected to the first end of the thermistor RT1 and grounded; The second end of the resistor R7 is connected to the 5V1 power supply.

10. The toaster secondary protection circuit according to claim 7, characterized in that: The controller also includes a button SW1 and an adjustable potentiometer VER1; The second pin of the adjustable potentiometer VER1 is connected to the PA2 pin of the integrated circuit U1; the third and fourth pins are connected to the 5V1 power supply respectively; the first and fifth pins are grounded; The first end of the button SW1 is connected to the second end of the resistor R8 , and the second end is respectively connected to the negative electrode of the electrolytic capacitor EC1 and the second pin of the integrated circuit U2 , and is grounded.

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