Toaster and control circuit of switch control board thereof

Abstract

The utility model relates to a toaster and a control circuit of a switch control panel of the toaster, the control circuit comprises a power supply module, a temperature detection sensor electrically connected with the power supply module and a controlled switch module, and the temperature detection sensor is arranged to be a current-limiting resistor close to the power supply module at a setting position. The controlled switch module is electrically connected with a main control unit of the toaster, the start-stop switch and the heating wire in a coupling mode, the start-stop switch is adopted to control connection and disconnection of the commercial power grid and the controlled switch module, and the power supply module supplies power to the temperature detection sensor and the controlled switch module. The temperature of the current-limiting resistor and the temperature of the surrounding environment are detected through the temperature detection sensor, the on-off of the corresponding heating wire and the start-stop switch is controlled through the controlled switch module so as to correspondingly control the on-off of the heating wire, the state of the whole machine is judged through the main control unit, and based on the state of the whole machine and a preset baking mode, baking is conducted. And the controlled switch module is controlled to carry out power-on and power-off control on the heating wire.

Description

Technical Field

[0001] This application relates to the technical field of electric cooker control, and particularly relates to a toaster and a control circuit of its switch control board. Background Art

[0002] In life, as a common baking device, the toaster has a high usage frequency. However, when the existing toaster bakes bread, it usually adopts a simple temperature sensing method, which leads to inconsistent baking effects. Thus, the bread may become charred due to too long baking time, or fail to achieve the ideal baking effect due to insufficient baking time. The reason for this situation is that the whole toaster is wrapped by a shell and has no heat dissipation system. During the heating process, the temperature of the whole toaster will gradually increase. Within a certain period of time after starting heating (for example, within 1 minute), the temperature of the heating chamber of the toaster has not been conducted to the whole machine. At this time, there is a large error between the detected temperature, which is regarded as the temperature of the whole toaster by the temperature detection device of the toaster, and the actual current temperature of the whole machine. And the heating control of the toaster is based on the current temperature of the whole machine. Thus, when baking according to the set mode, the baking time may be insufficient or too long due to the temperature error, resulting in the heating wire of the toaster not being powered off in time and poor baking effects.

[0003] Currently, for the problem that the detected temperature of the whole toaster in the related technology has a large error from the actual temperature of the whole machine, resulting in poor baking effects, no effective solution has been proposed. Utility Model Content

[0004] In view of this, it is necessary to provide a toaster and a control circuit of its switch control board to at least solve the problem that the detected temperature of the whole toaster in the related technology has a large error from the actual temperature of the whole machine, resulting in poor baking effects.

[0005] In a first aspect, the present application provides a technical solution as follows: A control circuit for a switch control board, which is used to control a toaster. The switch control board is electrically connected to the main control unit of the toaster, the heating wires provided on the upper cover and the bottom cover of the toaster, and the start-stop switch. The start-stop switch is also electrically connected to the main control unit for control. The control circuit includes a power supply module, a temperature detection sensor electrically connected to the power supply module, and a controlled switch module. The temperature detection sensor is arranged at a position close to the current-limiting resistor of the power supply module. The controlled switch module is respectively coupled and electrically connected to the main control unit, the start-stop switch, and the heating wires. Among them, the start-stop switch is used to control the on-off of the mains power supply and the controlled switch module; the power supply module is used to supply power to the temperature detection sensor and the controlled switch module; the temperature detection sensor is used to detect the current overall temperature of the toaster by detecting the temperature of the current-limiting resistor and its surrounding environment; the controlled switch module is used to control the on-off of the corresponding heating wire and the start-stop switch to correspondingly control the energization and de-energization of the heating wire; the main control unit is used to, when the start-stop switch is turned on, judge the overall state of the toaster according to the received current overall temperature, and based on the overall state and the preset baking mode, control the controlled switch module to perform energization and de-energization control on the heating wire, and control the start-stop switch to turn off to terminate the heating operation of the toaster.

[0006] In a second aspect, an embodiment of the present application further provides a toaster, which includes a switch control board, and a switch control circuit is provided on the switch control board, and the switch control circuit is the control circuit described in the first aspect.

[0007] Compared with the related art, a control circuit for a toaster and its switch control board is provided in this embodiment. The control circuit includes a power supply module, a temperature detection sensor electrically connected to the power supply module, and a controlled switch module. The temperature detection sensor is arranged at a position close to the current-limiting resistor of the power supply module. The controlled switch module is respectively coupled and electrically connected to the main control unit, the start-stop switch, and the heating wire of the toaster. The on-off of the mains power supply and the controlled switch module is controlled by the start-stop switch. The power supply module supplies power to the temperature detection sensor and the controlled switch module. The temperature detection sensor detects the temperature of the current-limiting resistor and its surrounding environment to detect the current overall temperature of the toaster. The on-off of the corresponding heating wire and the start-stop switch is controlled by the controlled switch module to correspondingly control the on-off of the heating wire. When the start-stop switch is turned on, the main control unit judges the overall state of the toaster according to the received current overall temperature, and based on the overall state and the preset baking mode, controls the controlled switch module to perform on-off control of the heating wire, and controls the start-stop switch to turn off to terminate the heating operation of the toaster, solving the problem in the related art that the error between the detected overall temperature of the toaster and the actual overall temperature is large, resulting in poor baking effect, and achieving the beneficial effect of quickly judging the temperature of the furnace core or the ambient temperature corresponding to the toaster and improving the baking effect.

[0008] Details of one or more embodiments of the present application are set forth in the following drawings and description, so that other features, objects, and advantages of the present application will become more clearly understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention and used together with the specification to explain the principles of the present invention.

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0011] Figure 1 It is a structural block diagram of a control circuit for a switch control board provided in an embodiment of the present application;

[0012] Figure 2 It is a connection schematic diagram of the main control unit and the switch control board in an embodiment of the present application;

[0013] Figure 3 It is a topological structure diagram of a controlled switch module in an embodiment of the present application;

[0014] Figure 4 It is a topological schematic diagram of start-stop switch control in an embodiment of the present application;

[0015] Figure 5 This is the topological structure diagram of the power supply module according to the embodiment of the present application. Specific implementation manners

[0016] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0017] The electric kettle and control circuit of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application and through specific embodiments.

[0018] Refer to Figures 1 to 5 , the control circuit of the switch control board provided by the embodiment of the present application is used to control a toaster. The switch control board is electrically connected to the main control unit 100 of the toaster, the heating wire 200 provided on the upper cover and the bottom cover of the toaster, and the start-stop switch 300. The start-stop switch 300 is also electrically connected to the main control unit 100 for control. The control circuit includes a power supply module 400, a temperature detection sensor 500 electrically connected to the power supply module 400, and a controlled switch module 600. The temperature detection sensor 500 is arranged at a position close to the current-limiting resistor 41 of the power supply module 400. The controlled switch module 600 is respectively coupled and electrically connected to the main control unit 100, the start-stop switch 300, and the heating wire 200. Among them,

[0019] The start-stop switch 300 is used to control the on-off between the commercial power grid and the controlled switch module 600.

[0020] In this embodiment, the start-stop switch 300 is provided on the body of the toaster. When the top cover and the bottom cover of the toaster are attracted and closed, the start-stop switch 300 will be triggered to conduct, thereby connecting the mains power grid to the controlled switch module 600. That is, the power of the mains power grid is connected to the controlled switch module 600 at this time, so that the controlled switch module 600 connects the corresponding heating wire 200 according to the preset baking mode, and then performs the corresponding heating work. For example, the heating wire 200 located in either the top cover or the bottom cover can be powered on alone, or the heating wires 200 located on the top cover and the bottom cover can be powered on to make the toaster work in the full-power mode. In this embodiment, when the toaster works abnormally (for example, the temperature inside the toaster is too high, the baking target is stuck in the built-in bracket, or the top cover and the bottom cover are abnormally attracted and closed), the main control unit 100 will control the start-stop switch 300 to disconnect, so as to cut off the power supply of the controlled switch module 600, that is, disconnect the connection between the mains power grid and the controlled switch module 600. In this embodiment, the start-stop switch 300 can be one of the following: solenoid, micro electromagnet, solenoid valve.

[0021] The power supply module 400 is used to supply power to the temperature detection sensor 500 and the controlled switch module 600.

[0022] In this embodiment, the power supply module 400 converts the mains alternating current into the DC voltage for the temperature detection sensor 500 and the controlled switch module 600 to work. In this embodiment, the corresponding DC voltages include the DC voltage corresponding to the first power supply (+17V), the DC voltage corresponding to the second power supply (+29V), and the DC voltage corresponding to the third power supply (+5V).

[0023] In this embodiment, the current-limiting resistor 41 is arranged in the circuit of the power supply module 400. On the one hand, it is used for current limiting in the circuit to protect the circuit of the power supply module 400. On the other hand, through the heating of the current-limiting resistor 41, the temperature detection sensor 500 is heated. The temperature detection sensor 500 detects the temperature (higher than the ambient temperature) indicating that the toaster has been powered on for heating, so that when the temperature in the heating chamber of the toaster has not been conducted to the whole machine, the main control unit 100 can determine that the toaster has been powered on for heating.

[0024] The temperature detection sensor 500 is used to detect the current overall temperature of the toaster by detecting the temperature of the current-limiting resistor 41 and its surrounding environment.

[0025] In this embodiment, the temperature detection sensor 500 detects the temperature of the current limiting resistor 41 and its surrounding environment, thereby detecting the current overall temperature of the toaster. The detected current overall temperature corresponds to two situations. First, when the temperature in the heating chamber of the toaster has not been conducted to the whole machine but the toaster has started heating, at this time, the current limiting resistor 41 generates heat to raise the temperature of the environment around the temperature detection sensor 500, so that the temperature detected by the temperature detection sensor 500 is higher than the actual environmental temperature, that is, the detected current overall temperature representing that the toaster has started working; when the toaster has been working for a period of time, the temperature in the heating chamber is conducted to the whole machine. At this time, the temperature detection sensor 500 detects the temperature of the current limiting resistor 41 and its surrounding environment, both of which can represent the current actual overall temperature of the toaster, that is, the temperature of the environment around the current limiting resistor 41 corresponds to the temperature in the heating chamber; in this embodiment, when the toaster finishes heating, the temperature detection sensor 500 detects the current temperature T1 at the moment of power-off and stores the current temperature T1 in the main control unit 100. When the heating stops, the current limiting resistor 41 and the overall temperature of the machine will slowly drop. At the moment of power-on again after an interval of time, the temperature detection sensor 500 detects the environmental temperature around the current limiting resistor 41 to detect the overall temperature T2 of the toaster. The difference between T1 and T2 is compared with the temperature drop curve detected in the calibration mode (the preset temperature drop curve parameter table) to judge the current overall state of the toaster and the corresponding overall temperature. In this embodiment, the overall state of the machine includes the cold machine state and the hot machine state, and the overall temperature of the machine includes the overall temperature in the cold machine state and the overall temperature in the hot machine state; in this embodiment, the temperature detection sensor 500 includes but is not limited to an NTC thermistor.

[0026] The controlled switch module 600 is used to control the on-off of the corresponding heating wire 200 and the start-stop switch 300 to correspondingly control the on-off of the heating wire 200.

[0027] In this embodiment, the controlled switch module 600 is controlled by the main control unit 100 to control the power on and off of the heating wire 200, that is, the controlled switch module 600 controls the connection and disconnection of the corresponding heating wire 200 and the start-stop switch 300 connected to the mains power grid. When the controlled switch module 600 controls the connection of the heating wire 200 and the start-stop switch 300, and the start-stop switch 300 is not controlled to be disconnected from the mains power grid, the heating wire 200 is connected to the mains power grid and powered on for heating. When the start-stop switch 300 is controlled to be disconnected from the mains power grid, at this time, the toaster realizes power-off protection and the heating wire 200 is not allowed to work. After baking is completed, the main control unit 100 controls the controlled switch module 600 to disconnect the heating wire 200 from the start-stop switch 300 to stop the corresponding heating wire 200 from heating. In this embodiment, heating wires 200 are provided on both the upper cover and the bottom cover, and the controlled switch module 600 will separately perform corresponding heating operations on the heating wires 200 in different positions. For example, when only one side of the baking target needs to be baked, the controlled switch module 600 can be used to control the power on and off of one of the heating wires 200, and the other heating wire 200 is always in a power-off state.

[0028] The main control unit 100 is configured to, when the start-stop switch 300 is turned on, determine the overall state of the machine according to the currently received overall machine temperature, and based on the overall state and the preset baking mode, control the controlled switch module 600 to perform power on and off control on the heating wire 200, and control the start-stop switch 300 to disconnect to terminate the heating operation of the toaster.

[0029] In this embodiment, each time the heating ends according to the preset baking mode, the temperature of the current switch control board and the entire toaster (by detecting the temperature of the surrounding environment near the current-limiting resistor 41) is detected by the temperature detection sensor 500, denoted as T1, and transmitted to the main control unit 100 for storage. When power is applied again, the current temperature (by detecting the temperature of the surrounding environment near the current-limiting resistor 41) is detected by the temperature detection sensor 500, denoted as T2. The values of T2 and T1 are compared or it is determined whether T2 is lower than the cold machine temperature threshold. According to the difference result or the determination result, it is determined whether the entire machine is in a cold machine state or a hot machine state. Then, according to T2 and the current corresponding baking mode, the heating time required for this time is determined. Then, the main control unit 100 controls the controlled switch module 600 to control the corresponding heating wire 200 to be powered on, and the power-on time is the determined heating time required for this time. In this embodiment, when the main control unit 100 receives that the toaster is operating abnormally (for example, the furnace temperature in the heating chamber is abnormally high, the baking target is stuck in the bracket), the main control unit 100 will directly control the start-stop switch 300 to cut off the power supply to ensure electrical safety.

[0030] In this embodiment, the main control unit 200 can be a microcontroller MCU, a digital signal processor DSP, or a field programmable gate array FPGA. In some alternative embodiments, the main control unit 200 is preferably one of the following MCUs: R7F0C908B2 microprocessor, STC15F204 microcontroller, AT89S52 microcontroller, EN8F677E microprocessor.

[0031] For the above control circuit, the on-off of the mains power grid and the controlled switch module 600 is controlled by the start-stop switch 300, the temperature detection sensor 500 and the controlled switch module 600 are powered by the power module 400, and the temperature detection sensor 500 is used to detect the temperature of the current limiting resistor 41 and its surrounding environment to detect the current overall temperature of the toaster. The on-off of the corresponding heating wire 200 and the start-stop switch 300 is controlled by the controlled switch module 600 to correspondingly control the on-off of the heating wire 600. When the start-stop switch 300 is turned on, the main control unit 100 judges the overall state of the machine according to the received current overall temperature of the machine, and based on the overall state and the preset baking mode, controls the controlled switch module 600 to perform on-off control on the heating wire 200, and controls the start-stop switch 300 to turn off to terminate the heating operation of the toaster, solving the problem of large error between the detected overall temperature of the toaster and the actual overall temperature in the related technology, resulting in poor baking effect, and achieving the beneficial effect of quickly judging the core temperature or ambient temperature corresponding to the toaster and improving the baking effect.

[0032] It should be noted that, in this embodiment, the corresponding switch control board cooperates with the furnace body of the toaster and the corresponding main control unit 100, so as to control the heating wire 300 of the toaster to heat according to the preset baking mode, so as to realize the baking of the baking target as required.

[0033] To realize the on-off control of the heating wire 200 provided on the upper cover and the bottom cover by the controlled switch module 600, refer to Figures 1 to 5 , in some embodiments, the controlled switch module 600 includes a first controlled switch unit 61 and a second controlled switch unit 62. The first controlled switch unit 61 includes a first positive input port (refer to Figure 3 ACL_IN in Figure 3 ), a first negative input port (refer to Figure 3 ACL_OUT in Figure 3 ), a first positive output port (refer to Figure 3 the port corresponding to the net label HEATER_RL in Figure 3 ), a first negative output port (refer toFigure 3 the HT_BT1) and the second control terminal (refer to Figure 3 the port corresponding to the net label BAGEL_RL in Figure 3 and Figure 4 the ACL_SW1) in Figure 3 electrically connected to the positive output port of the start / stop switch 300 (refer to Figure 3 and Figure 4 the ACN_SW1) in Figure 3 the positive input port and the negative input port are respectively electrically connected to both ends of the heating wire 200 (refer to Figure 4 the L1) provided on the bottom cover, the second output port is electrically connected to the other end of the heating wire 200 provided on the upper cover, the first control terminal and the second control terminal are both coupled and electrically connected to the main control unit 100, the positive input port and the negative input port of the start / stop switch 300 are respectively electrically connected to the zero line and the live line of the mains power supply (refer to

[0034] The main control unit 100 is configured to, when the start / stop switch 300 connects the positive input port to the positive output port and the negative input port to the negative output port, respectively send a first switch signal and a second switch signal corresponding to the corresponding preset baking mode to the first controlled switch unit 61 and the second controlled switch unit 62.

[0035] The first controlled switch unit 61 is configured to control the on / off of the first positive input port and the first positive output port and control the on / off of the first negative input port and the first negative output port according to the level of the first switch signal received by the first control terminal, so as to control the on / off of the heating wire 200 provided on the bottom cover.

[0036] In this embodiment, when the level of the first switch signal indicates that the heating wire 200 is powered on, the first controlled switch unit 61 controls the connection of the first positive input port and the first positive output port, and the first negative input port and the first negative output port; when the level of the first switch signal indicates that the heating wire 200 is powered off, the first controlled switch unit 61 controls the disconnection of the first positive input port and the first positive output port, and the first negative input port and the first negative output port.

[0037] The second controlled switch unit 62 is configured to control the on / off of the second input port and the second output port according to the level of the second switch signal received by the second control terminal, so as to control the on / off of the heating wire 200 provided on the upper cover.

[0038] In this embodiment, when the level of the second switching signal indicates that the heating wire 200 is powered on, the second controlled switching unit 62 controls the second input port to communicate with the second output port; when the level of the second switching signal indicates that the heating wire 200 is powered off, the second controlled switching unit 62 controls the second input port to disconnect from the second output port.

[0039] To achieve on-off control of the heating wire 200 provided on the bottom cover, referring to Figures 1 to 5 , in some embodiments, the first controlled switching unit 61 includes two first controlled switches (referring to K2 and K3 in Figure 3 ) and a first switch driving circuit. The first controlled switch includes a first port (referring to the pin 1 of K2 and K3 in Figure 3 ), a second port (referring to the pin 2 of K2 and K3 in Figure 3 ), a third port (referring to the pin 3 of K2 and K3 in Figure 3 ), and a fourth port (referring to the pin 4 of K2 and K3 in Figure 3 ). The first ports of the two first controlled switches are both electrically connected to the first controlled end. The second ports of the two first controlled switches are both electrically connected to the first power supply (+17V). The third ports of the two first controlled switches are respectively connected to the first positive input port and the first negative input port. The fourth ports of the two first controlled switches are respectively connected to the first positive output port and the first negative output port. The first switch driving circuit includes a first switching transistor Q1 and a second switching transistor Q2. The input end of the first switching transistor Q1 is electrically connected to the second power supply (+29V). The controlled end of the second switching transistor Q2 is electrically connected to the second power supply through a series-connected first resistor R28. The controlled end of the first switching transistor Q1 is also electrically connected to the input end of the second switching transistor Q2 through a series-connected second resistor R29. The output end of the first switching transistor Q1 is electrically connected to the first controlled end. The controlled end of the second switching transistor Q2 is coupled to the main control unit 100 through a series-connected third resistor R30. The output end of the second switching transistor Q2 is grounded. Among them,

[0040] The second switching transistor Q2 is configured to control the on-off between the input end and the output end of the second switching transistor Q2 according to the level of the first switching signal received by its controlled end.

[0041] The first switching transistor Q1 is configured to output a corresponding first control signal along the output end of the first switching transistor Q1 according to the on-off between the input end and the output end of the second switching transistor Q2.

[0042] In this embodiment, when the input end and the output end of the second switching transistor Q2 are connected, the input end and the output end of the first switching transistor Q1 are connected, and the output end of the first switching transistor Q1 outputs a first control signal (corresponding to a low level) for controlling the corresponding heating wire 200 to be energized; when the input end and the output end of the second switching transistor Q2 are disconnected, the input end and the output end of the first switching transistor Q1 are disconnected, and the output end of the first switching transistor Q1 outputs a first control signal (corresponding to a high level) for controlling the corresponding heating wire 200 to be de-energized.

[0043] A first switch driving circuit for generating a first control signal and outputting the first control signal to a first port of two first controlled switches.

[0044] A first controlled switch for controlling the on / off of a third port and a fourth port of the first controlled switch according to the level of the received first control signal, so as to control the on / off of the heating wire 200 provided on the bottom cover.

[0045] In this embodiment, the first controlled switch includes, but is not limited to, a relay; when the first controlled switch is a relay, when the input end and the output end of the second switching transistor Q2 are connected, the input end and the output end of the first switching transistor Q1 are connected, and the output end of the first switching transistor Q1 outputs a first control signal of low level, and the input circuits of the relay K2 and the relay K3 are powered on and conducted, so that the moving contact and the static contact of the output circuit are in contact and conducted, that is, the third port and the fourth port of the first controlled switch are connected, and then the corresponding heating wire 200 is energized and heats up; when the input end and the output end of the second switching transistor Q2 are disconnected, the input end and the output end of the first switching transistor Q1 are disconnected, and the output end of the first switching transistor Q1 outputs a first control signal of high level, the input circuits of the relay K2 and the relay K3 do not form a conduction loop, and the output circuit of the relay has no corresponding response, that is, the moving contact and the static contact do not attract, the third port and the fourth port of the first controlled switch are disconnected, and the corresponding heating wire 200 is de-energized.

[0046] It can be understood that, it should be noted that the first switching transistor Q1 and the second switching transistor Q2 in the embodiments of the present application include, but are not limited to, triodes, MOS transistors, and field effect transistors. And, according to the content disclosed in the present application, those skilled in the art can easily think of modifying the first switching transistor Q1 and the second switching transistor Q2 disclosed in the present application into a first switch driving circuit adapted to the type selection of the switching transistor according to the specific type selection of the first switching transistor Q1 and the second switching transistor Q2. Therefore, whether the switching transistor is an NPN-type or PNP-type triode, or an N-channel or P-channel switching MOS transistor, or an N-type or P-type field effect transistor, the present application can be implemented, and no limitation is made in the embodiments of the present application.

[0047] To realize the on / off control of the heating wire 200 provided on the upper cover, refer toFigures 1 to 5 , in some embodiments thereof, the second controlled switch unit 62 includes a second controlled switch RE1 and a second switch driving circuit. The second controlled switch RE1 includes a fifth port (refer to pin 1 of RE1 in Figure 3 ), a sixth port (refer to pin 2 of RE1 in Figure 3 ), a seventh port (refer to pin 3 of RE1 in Figure 3 ), and an eighth port (refer to pin 4 of RE1 in Figure 3 ). The fifth port is electrically connected to the second controlled end. The sixth port is electrically connected to the third power supply (+5V). The seventh port is docked with the second input port. The eighth port is docked with the second output port. The second switch driving circuit includes a third switching transistor Q3 and a fourth switching transistor Q4. The input end of the third switching transistor Q3 is electrically connected to the first power supply (+17V). The controlled end of the third switching transistor Q3 is electrically connected to the first power supply through a series-connected fourth resistor R24. The controlled end of the third switching transistor Q3 is also electrically connected to the input end of the fourth switching transistor Q4 through a series-connected fifth resistor R5. The output end of the third switching transistor Q3 is electrically connected to the second controlled end. The controlled end of the fourth switching transistor Q4 is coupled and electrically connected to the main control unit 100 through a series-connected sixth resistor R27. The output end of the fourth switching transistor Q4 is grounded. Among them,

[0048] the fourth switching transistor Q4 is configured to control the on / off of the input end and the output end of the fourth switching transistor according to the level of the second switch signal received at its controlled end.

[0049] The third switching transistor Q3 is configured to output a corresponding second control signal along the output end of the third switching transistor according to the on / off of the input end and the output end of the fourth switching transistor Q4.

[0050] In this embodiment, when the input end and the output end of the fourth switching transistor Q4 are connected, the input end and the output end of the third switching transistor Q3 are connected, and the output end of the third switching transistor Q3 outputs a second control signal (corresponding to a low level) for controlling the corresponding heating wire 200 to be powered on; when the input end and the output end of the fourth switching transistor Q4 are disconnected, the input end and the output end of the third switching transistor Q3 are disconnected, and the output end of the third switching transistor Q3 outputs a second control signal (corresponding to a high level) for controlling the corresponding heating wire 200 to be powered off.

[0051] The second switch driving circuit is configured to generate a second control signal and output the second control signal to the fifth port.

[0052] The second controlled switch is configured to control the on / off of the seventh port and the eighth port of the second controlled switch according to the level of the first control signal received, so as to control the on / off of the heating wire 200 provided on the upper cover.

[0053] In this embodiment, the second controlled switch includes, but is not limited to, a relay. When the second controlled switch is a relay, when the input end and the output end of the fourth switching transistor Q4 are connected, the input end and the output end of the third switching transistor Q3 are connected, and a low-level second control signal is output at the output end of the third switching transistor Q3. The input loop of the relay RE1 is powered on and conducted, so that the moving contact and the static contact of its output loop are in contact and conducted, that is, the seventh port and the eighth port of the second controlled switch are connected, and then the corresponding heating wire 200 is powered on and heats up. When the input end and the output end of the fourth switching transistor Q4 are disconnected, the input end and the output end of the third switching transistor Q3 are disconnected, and a high-level second control signal is output at the output end of the third switching transistor Q3. The input loop of the relay RE1 does not form a conducting loop, and the output loop of the relay RE1 has no corresponding response, that is, the moving contact and the static contact do not attract, the seventh port and the eighth port of the second controlled switch are disconnected, and the corresponding heating wire 200 is powered off.

[0054] It can be understood that it should be noted that the third switching transistor Q3 and the fourth switching transistor Q4 in the embodiments of the present application include, but are not limited to, triodes, MOS transistors, and field effect transistors. And according to the content disclosed in the present application, those skilled in the art can easily think of modifying the third switching transistor Q3 and the fourth switching transistor Q4 disclosed in the present application into a second switch driving circuit adapted to the switch type according to the specific selection of the third switching transistor Q3 and the fourth switching transistor Q4. Therefore, whether the switching transistor is an NPN-type or PNP-type triode, or an N-channel or P-channel switching MOS transistor, or an N-type or P-type field effect transistor, the present application can be implemented, and no limitation is made in the embodiments of the present application.

[0055] To realize the control of the start-stop switch 300, in some embodiments, refer to Figures 1 to 5 , the start-stop switch 300 is coupled and electrically connected to the main control unit 100 through a third switch driving circuit. The third switch driving circuit includes a fifth switching transistor Q5 and a sixth switching transistor Q6. The input end of the fifth switching transistor Q5 is electrically connected to the first power supply (+17V). The controlled end of the fifth switching transistor Q5 is electrically connected to the first power supply (+17V) through a series-connected seventh resistor R20. The controlled end of the fifth switching transistor is also electrically connected to the input end of the sixth switching transistor Q6 through a series-connected eighth resistor R21. The output end of the fifth switching transistor Q5 is electrically connected to the controlled end of the start-stop switch 300. The controlled end of the sixth switching transistor Q6 is coupled and electrically connected to the main control unit 100 through a series-connected ninth resistor R22. The output end of the sixth switching transistor Q6 is grounded. Among them,

[0056] The main control unit 100 is configured to output a third switch signal when the upper cover and the bottom cover are abnormally attracted or the current temperature of the whole machine exceeds a preset temperature threshold.

[0057] The sixth switching transistor Q6 is configured to control the connection and disconnection between the input terminal and the output terminal of the sixth switching transistor Q6 according to the level of the third switching signal received at its control terminal.

[0058] The fifth switching transistor Q5 is configured to output a corresponding third control signal along the output terminal of the fifth switching transistor Q5 according to the connection and disconnection between the input terminal and the output terminal of the sixth switching transistor Q6.

[0059] In this embodiment, when the input terminal and the output terminal of the sixth switching transistor Q6 are connected, the input terminal and the output terminal of the fifth switching transistor Q5 are connected, and the output terminal of the fifth switching transistor Q5 outputs a third control signal (corresponding to a low level) for turning on the start-stop switch 300; when the input terminal and the output terminal of the sixth switching transistor Q6 are disconnected, the input terminal and the output terminal of the fifth switching transistor Q5 are disconnected, and the output terminal of the fifth switching transistor Q5 outputs a third control signal (corresponding to a high level) for turning off the start-stop switch 300.

[0060] The third switching drive circuit is configured to generate a third control signal and output the third control signal to the start-stop switch 300.

[0061] The start-stop switch 300 is configured to control the connection and disconnection between the input terminal and the output terminal of the start-stop switch 300 according to the level of the third control signal received, so as to correspondingly control the connection and disconnection between the municipal power grid and the controlled switch module 600.

[0062] To provide a working power supply to the controlled switch module 600, in some of these embodiments, the power supply module 400 further includes: an over-current and surge protection circuit 42, including a fuse F1, a varistor RV1, a safety capacitor CX1, and a protection resistor (composed of series resistors RX1 and RX2). The first end of the fuse F1 is electrically connected to the live wire (ACL_SW). The second end of the fuse F1 is electrically connected to the first end of the current-limiting resistor 41 and one end of the parallel-connected varistor RV1, safety capacitor CX1, and protection resistor. The other ends of the parallel-connected varistor RV1, safety capacitor CX1, and protection resistor are electrically connected to the neutral wire (CAN_SW); an RC step-down circuit 43, including a step-down capacitor CX2 and a first discharge resistor (including series resistors RX3 and RX4). The step-down capacitor CX2 and the first discharge resistor are connected in parallel and are respectively electrically connected to the second end of the current-limiting resistor 41 (corresponding to resistor R1) and the input end of the rectifier bridge DB1; a first filtering unit 44, including a first electrolytic capacitor CE1. The positive electrode of the first electrolytic capacitor CE1 is electrically connected to the positive output end of the rectifier bridge DB1 and the first power supply port of the power supply module 400 (corresponding to the output port of the second power supply); a first voltage stabilizing unit 45, including a first voltage stabilizing diode ZD1. The cathode of the first voltage stabilizing diode ZD1 is electrically connected to the first power supply port. The anode of the first voltage stabilizing diode ZD1 is electrically connected to the second power supply port of the power supply module 400 (corresponding to the output port of the first power supply) and the input end of the second voltage stabilizing unit 46; a second voltage stabilizing unit 46, including a second voltage stabilizing diode ZD2 and a third voltage stabilizing diode ZD3. The cathode of the second voltage stabilizing diode ZD2 is connected to the input end of the second voltage stabilizing unit 46. The anode of the second voltage stabilizing diode ZD2 is electrically connected to the output end of the second voltage stabilizing unit 46 and the cathode of the third voltage stabilizing diode ZD3. The output end of the second voltage stabilizing unit 46 is also electrically connected to the third power supply port of the power supply module 400 (corresponding to the output port of the third power supply). The anode of the third voltage stabilizing diode ZD3 is electrically connected to the signal ground; a second filtering unit 47, including a parallel-connected second electrolytic capacitor CE2, a first filtering capacitor C1, and a second discharge resistor R5. The first end of the second filtering unit 47 is electrically connected to the third power supply port. The second end of the second filtering unit 47 is electrically connected to the temperature detection sensor 500 and is electrically connected to the signal ground, where,

[0063] The over-current and surge protection circuit 42 is used to perform over-current protection and surge protection on the input end of the power supply module 400 through the fuse and the varistor, and to filter the input mains AC power through the safety capacitor.

[0064] In this embodiment, after the mains AC 220V is input, it first passes through the fuse F1 to provide the function of over-current protection. Then it passes through RV1 and CX1. RV1 is a varistor used for surge protection and lightning protection; CX1 is a safety capacitor used for filtering.

[0065] The RC step-down circuit 43 is used to step down the filtered AC power from the mains power grid to a first AC voltage.

[0066] In this embodiment, the step-down capacitor CX1 uses a large capacitive reactance to limit the total current of the circuit. The resistors RX3 and RX4 are connected in series to form a discharge resistor, which provides a discharge path for the step-down capacitor CX1 after power-off to prevent the residual voltage on the step-down capacitor CX1 from being superimposed on the grid voltage and forming a high-voltage impact on subsequent devices.

[0067] The rectifier bridge is used to rectify the first AC voltage into a second voltage corresponding to the second power supply.

[0068] The first filtering unit 44 is used to filter the second voltage.

[0069] The first voltage stabilizing unit 45 is used to stabilize the filtered second voltage into a first voltage corresponding to the first power supply.

[0070] The second voltage stabilizing unit 46 is used to stabilize the first voltage into a third voltage corresponding to the third power supply.

[0071] The second filtering unit 47 is used to filter the third voltage.

[0072] The embodiment of the present application also provides a toaster, which includes a switch control board. A switch control circuit is provided on the switch control board, and this control circuit is the control circuit in the above embodiment.

[0073] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, and further include other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0074] The above are only the specific embodiments of the present invention, which enable those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A control circuit for a switch control board, which is used to control a toaster. The switch control board is electrically connected to the main control unit (100) of the toaster, the heating wires (200) provided on the upper cover and the bottom cover of the toaster, and the start-stop switch (300). The start-stop switch (300) is also electrically connected to the main control unit (100) for control, and is characterized in that, The control circuit includes a power supply module (400), a temperature detection sensor (500) electrically connected to the power supply module (400), and a controlled switch module (600). The temperature detection sensor (500) is arranged at a set position close to the current-limiting resistor (41) of the power supply module (400). The controlled switch module (600) is respectively coupled and electrically connected to the main control unit (100), the start-stop switch (300), and the heating wire (200). Among them, the start-stop switch (300) is used to control the on-off of the mains power supply and the controlled switch module (600); the power supply module (400) is used to supply power to the temperature detection sensor (500) and the controlled switch module (600); the temperature detection sensor (500) is used to detect the current overall temperature of the toaster by detecting the temperature of the current-limiting resistor (41) and its surrounding environment; the controlled switch module (600) is used to control the on-off of the corresponding heating wire (200) and the start-stop switch (300), so as to correspondingly control the power-on and power-off of the heating wire (200); the main control unit (100) is used to, when the start-stop switch (300) is turned on, judge the overall state of the machine according to the received current overall temperature of the machine, and based on the overall state and the preset baking mode, control the controlled switch module (600) to perform power-on and power-off control on the heating wire (200), and control the start-stop switch (300) to turn off to terminate the heating operation of the toaster.

2. The control circuit according to claim 1, wherein The controlled switch module (600) includes a first controlled switch unit (61) and a second controlled switch unit (62). The first controlled switch unit (61) includes a first positive input port, a first negative input port, a first positive output port, a first negative output port, and a first control end. The second controlled switch unit (62) includes a second input port, a second output port, and a second control end. The first positive input port and the second input port are both electrically connected to the positive output port of the start-stop switch (300). The first negative input port and one end of the heating wire (200) provided on the upper cover are both electrically connected to the negative output port of the start-stop switch (300). The first positive output port and the first negative output port are respectively electrically connected to both ends of the heating wire (200) provided on the bottom cover. The second output port is electrically connected to the other end of the heating wire (200) provided on the upper cover. The first control end and the second control end are both coupled and electrically connected to the main control unit (100). The positive input port and the negative input port of the start-stop switch (300) are respectively electrically connected to the neutral wire and the live wire of the mains power supply. Among them, The main control unit (100) is configured to, when the start-stop switch (300) connects the positive input port to the positive output port and the negative input port to the negative output port, respectively send a first switch signal and a second switch signal corresponding to a corresponding preset baking mode to the first controlled switch unit (61) and the second controlled switch unit (62); The first controlled switch unit (61) is configured to control the on / off of the first positive input port and the first positive output port and the on / off of the first negative input port and the first negative output port according to the level of the first switch signal received at the first controlled end, so as to control the on / off power supply of the heating wire (200) provided on the bottom cover; The second controlled switch unit (62) is configured to control the on / off of the second input port and the second output port according to the level of the second switch signal received at the second controlled end, so as to control the on / off power supply of the heating wire (200) provided on the upper cover.

3. The control circuit according to claim 2, wherein The first controlled switch unit (61) includes two first controlled switches and a first switch driving circuit. The first controlled switch includes a first port, a second port, a third port, and a fourth port. The first ports of the two first controlled switches are electrically connected to the first controlled end. The second ports of the two first controlled switches are electrically connected to a first power supply. The third ports of the two first controlled switches are respectively connected to the first positive input port and the first negative input port. The fourth ports of the two first controlled switches are respectively connected to the first positive output port and the first negative output port. The first switch driving circuit includes a first switch tube and a second switch tube. The input end of the first switch tube is electrically connected to a second power supply. The controlled end of the first switch tube is electrically connected to the second power supply through a series-connected first resistor. The controlled end of the first switch tube is also electrically connected to the input end of the second switch tube through a series-connected second resistor. The output end of the first switch tube is electrically connected to the first controlled end. The controlled end of the second switch tube is coupled and electrically connected to the main control unit (100) through a series-connected third resistor. The output end of the second switch tube is grounded. Among them, The second switch tube is configured to control the on / off of the input end and the output end of the second switch tube according to the level of the first switch signal received at its controlled end; The first switch tube is configured to output a corresponding first control signal along the output end of the first switch tube according to the on / off of the input end and the output end of the second switch tube; The first switch driving circuit is configured to generate the first control signal and output the first control signal to the first ports of the two first controlled switches; The first controlled switch is configured to control the on / off of the third port and the fourth port of the first controlled switch according to the level of the first control signal received, so as to control the on / off power supply of the heating wire (200) provided on the bottom cover.

4. The control circuit according to claim 3, wherein The first controlled switch includes a relay.

5. The control circuit according to claim 3, wherein The second controlled switch unit (62) includes a second controlled switch and a second switch driving circuit. The second controlled switch includes a fifth port, a sixth port, a seventh port, and an eighth port. The fifth port is electrically connected to the second controlled terminal. The sixth port is electrically connected to a third power supply. The seventh port is docked with the second input port. The eighth port is docked with the second output port. The second switch driving circuit includes a third switch tube and a fourth switch tube. The input end of the third switch tube is electrically connected to a first power supply. The controlled end of the third switch tube is electrically connected to the first power supply through a series-connected fourth resistor. The controlled end of the third switch tube is also electrically connected to the input end of the fourth switch tube through a series-connected fifth resistor. The output end of the third switch tube is electrically connected to the second controlled terminal. The controlled end of the fourth switch tube is coupled and electrically connected to the main control unit (100) through a series-connected sixth resistor. The output end of the fourth switch tube is grounded. Wherein, The fourth switch tube is configured to control the on / off between the input end and the output end of the fourth switch tube according to the level of the second switch signal received at its controlled end; The third switch tube is configured to output a corresponding second control signal along the output end of the third switch tube according to the on / off between the input end and the output end of the fourth switch tube; The second switch driving circuit is configured to generate the second control signal and output the second control signal to the fifth port; The second controlled switch is configured to control the on / off between the seventh port and the eighth port of the second controlled switch according to the level of the first control signal received, so as to control the on / off of the heating wire (200) provided on the upper cover.

6. The control circuit according to claim 5, characterized in that, The second controlled switch includes a relay.

7. The control circuit according to claim 1, wherein The start / stop switch (300) is coupled and electrically connected to the main control unit (100) through a third switch driving circuit. The third switch driving circuit includes a fifth switch tube and a sixth switch tube. The input end of the fifth switch tube is electrically connected to a first power supply. The controlled end of the fifth switch tube is electrically connected to the first power supply through a series-connected seventh resistor. The controlled end of the fifth switch tube is also electrically connected to the input end of the sixth switch tube through a series-connected eighth resistor. The output end of the fifth switch tube is electrically connected to the controlled end of the start / stop switch (300). The controlled end of the sixth switch tube is coupled and electrically connected to the main control unit (100) through a series-connected ninth resistor. The output end of the sixth switch tube is grounded. Wherein, The main control unit (100) is configured to output a third switch signal when the upper cover and the bottom cover are abnormally attracted or the current overall machine temperature exceeds a preset temperature threshold; The sixth switch tube is configured to control the on / off between the input end and the output end of the sixth switch tube according to the level of the third switch signal received at its controlled end; The fifth switch tube is configured to output a corresponding third control signal along the output end of the fifth switch tube according to the on / off between the input end and the output end of the sixth switch tube; The third switch driving circuit is configured to generate the third control signal and output the third control signal to the start-stop switch (300). The start-stop switch (300) is configured to control the on / off of the input end and the output end of the start-stop switch (300) according to the level of the received third control signal, so as to correspondingly control the on / off of the municipal power grid and the controlled switch module (600).

8. The control circuit according to claim 1, wherein The power supply module (400) further includes: An over-current and surge protection circuit (42), including a fuse, a varistor, a safety capacitor and a protection resistor. The first end of the fuse is electrically connected to the live wire, the second end of the fuse is electrically connected to the first end of the current-limiting resistor (41) and one end of the varistor, the safety capacitor and the protection resistor connected in parallel, and the other ends of the varistor, the safety capacitor and the protection resistor connected in parallel are electrically connected to the neutral wire; An RC step-down circuit (43), including a step-down capacitor and a first discharge resistor. The step-down capacitor and the first discharge resistor are connected in parallel and are respectively electrically connected to the second end of the current-limiting resistor (41) and the input end of the rectifier bridge stack; A first filtering unit (44), including a first electrolytic capacitor. The positive electrode of the first electrolytic capacitor is electrically connected to the positive output end of the rectifier bridge stack and the first power supply port of the power supply module (400); A first voltage stabilizing unit (45), including a first voltage stabilizing diode. The cathode of the first voltage stabilizing diode is electrically connected to the first power supply port, and the anode of the first voltage stabilizing diode is electrically connected to the second power supply port of the power supply module (400) and the input end of the second voltage stabilizing unit (46); The second voltage stabilizing unit (46), including a second voltage stabilizing diode and a third voltage stabilizing diode. The cathode of the second voltage stabilizing diode is connected to the input end of the second voltage stabilizing unit (46), the anode of the second voltage stabilizing diode is electrically connected to the output end of the second voltage stabilizing unit (46) and the cathode of the third voltage stabilizing diode, the output end of the second voltage stabilizing unit (46) is also electrically connected to the third power supply port of the power supply module (400), and the anode of the third voltage stabilizing diode is electrically connected to the signal ground; A second filtering unit (47), including a second electrolytic capacitor, a first filtering capacitor and a second discharge resistor connected in parallel. The first end of the second filtering unit (47) is electrically connected to the third power supply port, and the second end of the second filtering unit (47) is electrically connected to the temperature detection sensor (500) and electrically connected to the signal ground. Among them, The over-current and surge protection circuit (42) is configured to perform over-current protection and surge protection on the input end of the power supply module (400) through the fuse and the varistor, and filter the input municipal power grid alternating current through the safety capacitor; The RC step-down circuit (43) is configured to step down the filtered municipal power grid alternating current to a first alternating voltage; The rectifier bridge stack is configured to rectify the first alternating voltage into a second voltage corresponding to the second power supply; The first filtering unit (44) is configured to filter the second voltage; The first voltage stabilizing unit (45) is configured to stabilize the second voltage that has completed filtering to a first voltage corresponding to a first power supply; The second voltage stabilizing unit (46) is configured to stabilize the first voltage to a third voltage corresponding to a third power supply: The second filtering unit (47) is configured to filter the third voltage.

9. The control circuit according to claim 8, characterized in that The temperature detection sensor (500) includes an NTC thermistor.

10. A toaster, comprising a switch control board, wherein a switch control circuit is provided on the switch control board, characterized in that, The switch control circuit includes the control circuit according to any one of claims 1 to 9.

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