Power circuits and electrical equipment

Abstract

The present application relates to a power supply circuit and an electrical device. When the power supply is connected to the switch control circuit, the user can control the switch control circuit to be turned on or off by sending a pressing signal to the switch control circuit, so that the power supply is connected to the power conversion circuit, and the power is supplied to the load after conversion by the power conversion circuit. During the power supply process, the user can change the voltage level that the power conversion circuit ultimately outputs to the load by sending a pressing signal to the level adjustment circuit, thereby achieving load level adjustment. In the above scheme, the load level adjustment is realized through a hardware circuit, and there is no need to set up an additional main control chip, so there is no need to develop a specific application program. This effectively solves the problem that the level switching in the electrical equipment requires the use of a main control chip equipped with a specific application program, which is difficult to develop.

Description

Technical Field

[0001] The present application relates to the technical field of control circuits, and in particular to a power supply circuit and an electrical device. Background Art

[0002] With the development of science and technology, electrical appliances with gear adjustment functions, such as handheld fans, hair dryers, humidifiers, shavers, and LED (light-emitting diode) lamps, are becoming more and more widely used in daily life.

[0003] These electrical devices typically include a main control chip. This chip detects the user's power on / off or switching actions and, based on an internal application, outputs corresponding control signals to the power conversion circuit to change the voltage output to the load, achieving power on / off and gear switching control. However, this control method requires a specific application to be installed on the main control chip, making it difficult to develop. Summary of the Invention

[0004] Based on this, it is necessary to provide a power supply circuit and electrical equipment to solve the problem that the gear switching in the electrical equipment requires the use of a main control chip equipped with a specific application and is difficult to develop.

[0005] A power supply circuit includes: a switch control circuit, a power conversion circuit and a gear adjustment circuit, wherein the switch control circuit is used to connect to a power supply, the switch control circuit and the gear adjustment circuit are respectively connected to the power conversion circuit, and the power conversion circuit is used to connect to a load; the switch control circuit is used to turn on or off the connection between the power conversion circuit and the power supply according to a pressing signal; and the gear adjustment circuit is used to change the voltage gear output by the power conversion circuit to the load according to the pressing signal.

[0006] In the above-mentioned power supply circuit, when the power supply is connected to the switch control circuit, the user can control the switch control circuit to be turned on or off by sending a pressing signal to the switch control circuit, so that the power supply is connected to the power conversion circuit, and the power is supplied to the load after conversion by the power conversion circuit. During the power supply process, the user can change the voltage level that the power conversion circuit ultimately outputs to the load by sending a pressing signal to the level adjustment circuit, thereby achieving load level adjustment. In the above-mentioned solution, the load level adjustment is realized through the hardware circuit, and there is no need to set up an additional main control chip, so there is no need to develop a specific application program. This effectively solves the problem that the level switching in electrical equipment requires the use of a main control chip equipped with a specific application program, which is difficult to develop.

[0007] In one embodiment, the switch control circuit includes a voltage divider circuit, a first switch circuit, a second switch circuit and a first touch switch circuit. The voltage divider circuit is connected to the power supply, the first switch circuit, the second switch circuit and the first touch switch circuit. The first switch circuit is also connected to the power supply, the second switch circuit, the first touch switch circuit and the power conversion circuit. The second switch circuit is also connected to the first touch switch circuit.

[0008] In one embodiment, the voltage divider circuit includes a resistor R1 and a resistor R2, the resistor R1 is connected to the first switch circuit, the power supply, and the resistor R2, and the resistor R2 is further connected to the first switch circuit, the second switch circuit, and the first touch switch circuit;

[0009] And / or, the first switching circuit includes a switching device U1 and a resistor R3, the switching device U1 is connected to the power supply, the voltage divider circuit, the power conversion circuit and the resistor R3, and the resistor R3 is also connected to the first touch switch circuit and the second switching circuit.

[0010] In one embodiment,

[0011] The second switch circuit includes a switch device Q1, the switch device Q1 is connected to the voltage divider circuit, the first touch switch circuit and the first switch circuit, and the switch device Q1 is grounded;

[0012] And / or, the first touch switch circuit includes a touch switch SW1, a capacitor C1, a capacitor C2, a resistor R4 and a resistor R5, the resistor R4 is connected to the voltage divider circuit, the second switch circuit, the touch switch SW1 and the capacitor C1, the touch switch SW1 is also connected to the capacitor C1, the capacitor C2 and the resistor R5, the resistor R5 is also connected to the second switch circuit and the first switch circuit, and the capacitor C1, the capacitor C2 and the resistor R5 are grounded.

[0013] In one embodiment, the power conversion circuit includes an enabling circuit, an input circuit, an output circuit, a feedback circuit and a switching power supply chip. The enabling circuit is connected to the switching control circuit, the input circuit and the switching power supply chip. The input circuit is also connected to the switching control circuit, the switching power supply chip and the output circuit. The output circuit is also connected to the switching power supply chip, the feedback circuit and the load. The feedback circuit is also connected to the switching power supply chip and the gear adjustment circuit.

[0014] In one embodiment, the enabling circuit includes a resistor R6 and a resistor R7, the resistor R6 is connected to the switch control circuit, the input circuit, the switching power supply chip and the resistor R7, and the resistor R7 is grounded;

[0015] And / or, the input circuit includes a capacitor C3, the capacitor C3 is connected to the enabling circuit, the switch control circuit, the output circuit and the switching power supply chip, and the capacitor C3 is grounded.

[0016] In one embodiment, the output circuit includes an inductor L1, a rectifier circuit and a filter circuit. The inductor L1 is connected to the enable circuit, the input circuit, the switching power supply chip and the rectifier circuit. The rectifier circuit is also connected to the switching power supply chip, the feedback circuit and the filter circuit. The feedback circuit is also connected to the filter circuit and the load.

[0017] In one embodiment, the rectifier circuit includes a diode D1, and the diode D1 is connected to the switching power supply chip, the inductor L1, the feedback circuit and the filter circuit;

[0018] And / or, the filtering circuit includes a capacitor C4, the capacitor C4 is connected to the load and the feedback circuit, and the capacitor C4 is grounded.

[0019] In one embodiment, the feedback circuit includes a resistor R8 and a resistor R9, the resistor R8 is connected to the output circuit, the resistor R9, the switching power supply chip and the gear adjustment circuit, and the resistor R9 is grounded.

[0020] In one embodiment, the gear adjustment circuit includes a storage circuit, a third switch circuit, a fourth switch circuit and a second touch switch circuit, the third switch circuit is connected to the power conversion circuit, the fourth switch circuit, the storage circuit and the second touch switch circuit, and the fourth switch circuit is also connected to the power conversion circuit and the second touch switch circuit.

[0021] In one embodiment, the third switch circuit includes a resistor R10, a resistor R11, a resistor R12, a switch device U2, and a diode D2. The switch device U1 is connected to the resistor R10, the resistor R11, the fourth switch circuit, the diode D2, and the resistor R12. The resistor R10 is also connected to the power conversion circuit and the fourth switch circuit. The resistor R11 is also connected to the energy storage circuit, the diode D2, and the second touch switch circuit. The resistor R12 is also connected to the fourth switch circuit. The switch device U2 is grounded.

[0022] And / or, the fourth switching circuit includes a resistor R13, a resistor R14, a resistor R15, a switching device U3 and a diode D3, the switching device U3 connects the resistor R13, the resistor R14, the third switching circuit, the diode D3 and the resistor R15, the resistor R13 is also connected to the third switching circuit and the power conversion circuit, the resistor R14 is also connected to the diode D3 and the second touch switch circuit, the resistor R15 is also connected to the third switching circuit, and the switching device U3 is grounded.

[0023] In one embodiment, the second tact switch circuit includes a tact switch SW2, a resistor R16, a resistor R17, a capacitor C5, and a capacitor C6. The resistor R16 is connected to the capacitor C5, the third switch circuit, and the tact switch SW2. The capacitor C5 is also connected to the third switch circuit and the tact switch SW2. The resistor R17 is connected to the fourth switch circuit, the capacitor C6, and the tact switch SW2. The capacitor C6 is also connected to the fourth switch circuit and the tact switch SW2. The tact switch SW2 is grounded.

[0024] In one embodiment, the energy storage circuit includes a capacitor C7, the capacitor C7 is connected to the third switch circuit, and the capacitor C7 is grounded.

[0025] An electrical device comprises a load and the above-mentioned power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a schematic diagram of the power supply circuit structure in one embodiment of the present application;

[0028] Figure 2 This is a schematic diagram of the power supply circuit structure in another embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of the switch control circuit structure in one embodiment of the present application;

[0030] Figure 4 This is a schematic diagram of the power supply circuit structure in another embodiment of the present application;

[0031] Figure 5 This is a schematic diagram of the power conversion circuit structure in one embodiment of the present application;

[0032] Figure 6 This is a schematic diagram of the power supply circuit structure in another embodiment of the present application;

[0033] Figure 7 This is a schematic diagram of the gear adjustment circuit structure in one embodiment of the present application.

[0034] Explanation of the accompanying drawings: 103-switch control circuit, 104-power conversion circuit, 106-gear adjustment circuit, 202-voltage divider circuit, 204-first switch circuit, 206-second switch circuit, 208-first touch switch circuit, 401-enabling circuit, 402-input circuit, 403-output circuit, 404-switching power supply chip, 405-feedback circuit, 502-rectifier circuit, 504-filtering circuit, 602-third switch circuit, 604-fourth switch circuit, 606-energy storage circuit, 608-second touch switch circuit. DETAILED DESCRIPTION

[0035] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0036] See also Figure 1 A power supply circuit includes: a switch control circuit 102, a power conversion circuit 104 and a gear adjustment circuit 106, the switch control circuit 102 is used to connect to the power supply, the switch control circuit 102 and the gear adjustment circuit 106 are respectively connected to the power conversion circuit 104, and the power conversion circuit 104 is used to connect to the load; the switch control circuit 102 is used to turn on or off the connection between the power conversion circuit 104 and the power supply according to a pressing signal; the gear adjustment circuit 106 is used to change the voltage gear output by the power conversion circuit 104 to the load according to the pressing signal.

[0037] Specifically, the switch control circuit 102 is a circuit that performs a switch control function on the power input; the power conversion circuit 104 is a circuit that converts the input power into an electrical signal of a load type suitable for the electrical device; and the gear adjustment circuit 106 is a circuit that adjusts the voltage (voltage gear) output by the power conversion circuit 104 to the load. The two ends of the switch control circuit 102 are connected to the power supply and the power conversion circuit 104 respectively. When the switch control circuit 102 is turned on, the electrical energy output by the power supply is transmitted to the power conversion circuit 104 through the switch control circuit 102. Through the conversion processing of the power conversion circuit 104, the appropriate voltage is provided to the load, so that the load enters the default gear and starts working. When the switch control circuit 102 is turned off, the connection between the power supply and the power conversion circuit 104 is broken, the electrical energy cannot be transmitted to the power conversion circuit 104, and the corresponding load will also stop operating.

[0038] During load operation, the user can press the gear adjustment circuit 106 to control the gear adjustment circuit 106 to enter different working states, thereby changing the voltage output to the load by the power conversion circuit 104, that is, adjusting the voltage gear output to the load, and ultimately making the load run at different gears to achieve load gear adjustment.

[0039] It should be noted that the specific type of power conversion circuit 104 is not unique. The power conversion circuit 104 may also vary depending on the type of electrical equipment used in actual scenarios. In one embodiment, the power conversion circuit 104 may be an AC-DC (Alternating Current-Direct Current) conversion type circuit. By setting up the AC-DC type conversion circuit, the electrical equipment can start and operate the load when connected to an external AC power source.

[0040] In another embodiment, the power conversion circuit 104 can be configured as a DC-DC (Direct Current-Direct Current) conversion circuit. This configuration allows the load of the electrical device to start operating under the power provided by the internal power supply. In other words, by configuring different types of power conversion circuits 104, the power circuit can ultimately be used in different types of electrical devices. The specific type of power conversion circuit 104 used can be determined based on actual needs.

[0041] In the above-mentioned power supply circuit, when the power is connected to the switch control circuit 102, the user can control the switch control circuit 102 to be turned on or off by sending a pressing signal to the switch control circuit 102, so that the power is connected to the power conversion circuit 104, and the power is supplied to the load after conversion by the power conversion circuit 104. During the power supply process, the user can change the voltage level that the power conversion circuit 104 ultimately outputs to the load by sending a pressing signal to the level adjustment circuit 106, thereby achieving load level adjustment. In the above-mentioned solution, the load level adjustment is implemented through a hardware circuit, and there is no need to set up an additional main control chip, so there is no need to develop a specific application program. This effectively solves the problem that level switching in electrical equipment requires the use of a main control chip equipped with a specific application program, which is difficult to develop.

[0042] See also Figure 2 In one embodiment, the switch control circuit 102 includes a voltage divider circuit 202, a first switch circuit 204, a second switch circuit 206, and a first touch switch circuit 208. The voltage divider circuit 202 is connected to the power supply, the first switch circuit 204, the second switch circuit 206, and the first touch switch circuit 208. The first switch circuit 204 is also connected to the power supply, the second switch circuit 206, the first touch switch circuit 208, and the power conversion circuit 104. The second switch circuit 206 is also connected to the first touch switch circuit 208.

[0043] Specifically, when the power supply circuit is powered on, that is, when the power supply is connected to the voltage divider circuit 202 and the first switch circuit 204 of the switch control circuit 102, the first switch circuit 204 and the second switch circuit 206 are both in the cut-off state, that is, the power energy of the power supply cannot be transmitted to the rear-end power conversion circuit 104, and the load cannot start running.

[0044] When the user presses the first touch switch circuit 208, turning it on, the charging and discharging of the first touch switch circuit 208 causes the second switch circuit 206 to first enter the on state. Due to the on-state of the second switch circuit 206, the power supply voltage is divided by the voltage divider circuit 202 and transmitted to the first switch circuit 204. This changes the control voltage of the first switch circuit 204, causing the state of the first switch circuit 204 to change from the off state to the on state. Both the first switch circuit 204 and the second switch circuit 206 are now conducting. At this point, the power supply energy is transmitted through the first switch circuit 204 to the power conversion circuit 104. After conversion by the power conversion circuit 104, it is transmitted to the load, causing the load to start operating.

[0045] During load operation, if the user presses the first touch switch circuit 208, the charge / discharge state of the first touch switch circuit 208 changes, and both the first switch circuit 204 and the second switch circuit 206 switch from the on state to the off state. At this point, the power supply cannot be transmitted to the power conversion circuit 104 at the back end, and the load stops operating.

[0046] The above scheme utilizes the voltage divider circuit 202, the first switch circuit 204, the second switch circuit 206 and the first touch switch circuit 208 to build a switch control circuit 102. By pressing the first touch switch circuit 208, the charge and discharge state of the first touch switch circuit 208 is changed, so that the first switch circuit 204 and the second switch circuit 206 are turned on or off, thereby controlling the operation or stop of the load. It has the advantages of simple control method and low circuit cost.

[0047] See also Figure 3 In one embodiment, the voltage divider circuit includes a resistor R1 and a resistor R2, wherein the resistor R1 is connected to the first switch circuit 204, the power supply VBUS and the resistor R2, and the resistor R2 is further connected to the first switch circuit 204, the second switch circuit 206 and the first touch switch circuit 208.

[0048] Specifically, in the solution of this embodiment, the voltage divider circuit 202 is implemented using resistor voltage division. The first end of resistor R1 is connected to the power supply VBUS, the second end of resistor R1 is connected to the first end of resistor R2 and the first switch circuit 204, and the second end of resistor R2 is connected to the first touch switch circuit 208 and the second switch circuit 206. The voltage divider circuit 202 is constructed by resistors R1 and R2, which simplifies the circuit structure and reduces the circuit size of the power supply circuit to a certain extent.

[0049] Please continue reading Figure 3 In one embodiment, the first switch circuit 204 includes a switch device U1 and a resistor R3. The switch device U1 is connected to the power supply VBUS, the voltage divider circuit 202, the power conversion circuit 104 and the resistor R3. The resistor R3 is also connected to the first touch switch circuit 208 and the second switch circuit 206.

[0050] Specifically, the first switch circuit 204 includes a switch device U1 and a resistor R3, wherein the input end of the switch device U1 is connected to the power supply VBUS, the control end of the switch device U1 is connected to the voltage divider circuit 202, and the output end of the switch device U1 is connected to the power conversion circuit 104 (specifically, connected to the power conversion circuit 104 via the VIN port shown in the figure) and the first end of the resistor R3, and the second end of the resistor R3 is connected to the first touch switch circuit 208 and the second switch circuit 206. More specifically, in one embodiment, the input end of the switch device U1 is connected to the power supply VBUS, and the control end of the switch device U1 is connected to the second end of the resistor R1 and the first end of the resistor R2. When the switch device U1 is turned on, electrical energy is transmitted to the power conversion circuit 104 through the switch device U1. When the switch device U1 is turned off, electrical energy cannot be transmitted to the power conversion circuit 104.

[0051] It is understood that the specific type of switching device U1 is not limited. In one embodiment, switching device U1 is a field-effect transistor. In other embodiments, switching device U1 may also be another type of switching semiconductor device, such as a transistor or an insulated gate bipolar transistor. In practical scenarios, the specific type of switching device U1 is not limited and can be selected based on actual needs.

[0052] Please refer to Figure 3 In one embodiment, the second switch circuit 206 includes a switch device Q1 , which is connected to the voltage divider circuit 202 , the first touch switch circuit 208 , and the first switch circuit 204 , and is grounded.

[0053] Specifically, the second switching circuit 206 includes a switching device Q1, the input end of the switching device Q1 is connected to the voltage divider circuit 202 and the first touch switch circuit 208, the control end of the switching device Q1 is connected to the first switching circuit 204 and the first touch switch circuit 208, and the output end of the switching device Q1 is grounded (or connected to the negative pole of the power supply).

[0054] In more detail, in one embodiment, the input end of the switch device Q1 is connected to the second end of the resistor R2 and the first touch switch circuit 208 , and the control end of the switch device Q1 is connected to the second end of the resistor R3 and the first touch switch circuit 208 .

[0055] It is understood that the specific type of the switching device Q1 is not limited. In one embodiment, the switching device Q1 is a transistor. In other embodiments, the switching device Q1 may also be another type of switching semiconductor device, such as a field-effect transistor or an insulated gate bipolar transistor. In practical scenarios, the specific type of the switching device Q1 is not limited and can be selected based on actual needs.

[0056] Please refer to Figure 3 In one embodiment, the first touch switch circuit 208 includes a touch switch SW1, a capacitor C1, a capacitor C2, a resistor R4, and a resistor R5. The resistor R4 is connected to the voltage divider circuit 202, the second switch circuit 206, the touch switch SW1, and the capacitor C1. The touch switch SW1 is also connected to the capacitor C1, the capacitor C2, and the resistor R5. The resistor R5 is also connected to the second switch circuit 206 and the first switch circuit 204. The capacitor C1, the capacitor C2, and the resistor R5 are grounded.

[0057] Specifically, in the first touch switch circuit 208, the first end of the resistor R4 is connected to the voltage divider circuit 202 and the second switch circuit 206, the second end of the resistor R4 is connected to the first end of the touch switch SW1 and the first end of the capacitor C1, the second end of the touch switch SW1 is connected to the first end of the capacitor C2, the first end of the resistor R5 and the second switch circuit 206, and the second end of the capacitor C2, the second end of the capacitor C1 and the second end of the resistor R5 are grounded.

[0058] In more detail, in one embodiment, the first end of the resistor R4 is connected to the second end of the resistor R2 and the first end of the switch device Q1, and the second end of the touch switch SW1 is connected to the first end of the capacitor C2, the first end of the resistor R5 and the control end of the switch device Q1.

[0059] To facilitate understanding of the technical solution of this application, the operating principle of the switch control circuit 102 is explained in a more detailed embodiment in conjunction with its structure. In this embodiment, the voltage divider circuit 202 includes resistors R1 and R2, the first switch circuit 204 includes a switch device U1 and a resistor R3, the second switch circuit 206 includes a switch device Q1, and the first touch switch circuit 208 includes a touch switch SW1, a capacitor C1, a capacitor C2, a resistor R4, and a resistor R5.

[0060] When power supply VBUS is powered, that is, the first end of resistor R1 and the input end of switch device U1 are connected to power supply VBUS, touch switch SW1 is not pressed and is in the off state. The power supply VBUS flows through resistors R1, R2, R4, and capacitor C1 to the ground terminal (or the negative terminal of the power supply). The control terminal of switch device Q1 is grounded through resistor R5, and the output terminal of switch device Q1 is also grounded. At this time, switch device Q1 is in a low-level off state. Power supply VBUS charges capacitor C1 through resistors R1, R2, and R4. When capacitor C1 is fully charged, the voltage at the control terminal (gate in the case of a field-effect transistor) and the voltage at the input terminal (source in the case of a field-effect transistor) of switch device U1 are both equal to the power supply voltage. At this time, the gate-source voltage VGs of switch device U1 is 0, and the switch is in the off state. The power supply VBUS cannot be transmitted to the power conversion circuit 104, and there is no voltage output at the VIN point shown in the figure.

[0061] When the touch switch SW1 is pressed, capacitor C1 discharges and capacitor C2 charges. Because the voltage across capacitors cannot change suddenly, the voltage at the control terminal of switch device Q1 equals the voltage of capacitor C1, and switch device Q1 switches from the off state to the on state. At this point, power supply VBUS passes through resistors R1, R2, and the input terminal of switch device Q1, ultimately reaching ground through the output terminal of switch device Q1, forming a closed loop. After the power supply voltage is divided by voltage divider circuit 202, the voltage at the control terminal of switch device U1 is lower than the voltage at the input terminal, meaning that gate-source voltage VGS is less than 0, and switch device U1 switches from the off state to the on state. Power supply VBUS, on the one hand, passes through switch device U1 to power conversion circuit 104, causing power conversion circuit 104 to start operating. On the other hand, it passes through switch device U1, resistors R3, and R5 to ground. The voltage across resistor R5 and capacitor C2 equals the voltage when switch device Q1 is on (using a transistor as an example, this is 0.7V at this time). At the same time, the capacitor C1 is also discharged to the ground through the resistor R4, so that the input terminal voltage of the switching device Q1 is the saturation conduction voltage (taking the transistor as an example, it is 0.3V at this time).

[0062] When the touch switch SW1 is pressed again, the voltage across capacitor C1 is 0.3V, and the voltage across capacitor C2 is 0.7V. Capacitor C1 charges while capacitor C2 discharges, causing the voltage at the control terminal of switch device Q1 to drop, causing switch device Q1 to switch from the on state to the off state again. At the same time, power supply VBUS charges capacitor C1 through resistors R1, R2, and R4, causing the voltage at the control terminal of switch device U1 to increase, ultimately causing switch device U1 to switch back to the off state, shutting off the power output. Based on the above principle, as SW1 is pressed repeatedly, the subsequent power conversion circuit 104 switches back and forth between the energized and de-energized states, and the load is turned on or off accordingly.

[0063] See also Figure 4 In one embodiment, the power conversion circuit 104 includes an enabling circuit 401, an input circuit 402, an output circuit 403, a feedback circuit 405, and a switching power supply chip 404. The enabling circuit 401 is connected to the switching control circuit 102, the input circuit 402, and the switching power supply chip 404. The input circuit 402 is also connected to the switching control circuit 102, the switching power supply chip 404, and the output circuit 403. The output circuit 403 is also connected to the switching power supply chip 404, the feedback circuit 405, and the load. The feedback circuit 405 is also connected to the switching power supply chip 404 and the gear adjustment circuit 106.

[0064] Specifically, the enabling circuit 401 enables the switching power supply chip 404; the input circuit 402 processes the electrical energy output from the switching control device to the power conversion circuit 104; the output circuit 403 processes the electrical energy output to the load; and the feedback circuit 405 applies the feedback voltage from the level adjustment circuit 106 to the output circuit to change the output voltage level. The electrical energy processing operations of the input circuit 402 are not unique and may vary depending on the input electrical energy type, such as rectification, inversion, or filtering.

[0065] When the switch control circuit 102 is turned on, the enabling circuit 401 starts to operate. Under the enabling effect of the enabling circuit 401, the switching power supply chip 404 starts to operate and converts the received electric energy (AC-DC or DC-DC conversion can be performed according to actual conditions). After obtaining electric energy suitable for load operation, it is finally transmitted to the load through the output circuit 403 to power the load. During this process, the user can press the gear adjustment circuit 106 to connect the gear adjustment circuit 106 to the feedback circuit 405 in different states, and together with the feedback circuit 405, change the actual voltage output to the load, thereby changing the output voltage gear and achieving gear adjustment.

[0066] Please refer to Figure 5 In one embodiment, the enabling circuit 401 includes a resistor R6 and a resistor R7, the resistor R6 is connected to the switch control circuit 102, the input circuit 402, the resistor R7 and the switch power chip 404, and the resistor R7 is grounded.

[0067] Specifically, a first end of resistor R6 is connected to switch control circuit 102, input circuit 402, and power pin VIN of the switching power chip. A second end of resistor R6 is connected to switching power chip 404 and a first end of resistor R7. The second end of resistor R7 is grounded. In more detail, in one embodiment, a first end of resistor R6 is connected to a first end of resistor R3 and an output terminal of switching device U1. A second end of resistor R6 is connected to an enable pin SHDN of switching power chip 404.

[0068] The input circuit 402 is not limited to a single type. In one embodiment, the input circuit 402 may be different depending on the processing method required for the power output from the switch control circuit 102 to the power conversion circuit 104. For example, in one embodiment, the input circuit 402 is a filter circuit that filters the power transmitted to the power conversion circuit 104. Figure 5In one embodiment, the input circuit 402 includes a capacitor C3, which is connected to the enabling circuit 401, the switch control circuit 102, the output circuit 403 and the switching power supply chip 404 (specifically connected to the power pin VIN of the switching power supply chip 404), and the capacitor C3 is grounded.

[0069] Specifically, in this embodiment, the first end of capacitor C3 is connected to the first end of resistor R6 and switch control circuit 102, and the second end of capacitor C3 is grounded. This solution filters the input power through capacitor C3, simplifies the circuit structure, and effectively saves circuit cost and reduces circuit size.

[0070] See also Figure 5 In one embodiment, the output circuit 403 includes an inductor L1, a rectifier circuit 502, and a filter circuit 504. The inductor L1 is connected to the enable circuit 401, the input circuit 402, the switching power supply chip 404, and the rectifier circuit 502. The rectifier circuit 502 is also connected to the switching power supply chip 404, the feedback circuit 405, and the filter circuit 504. The feedback circuit 405 is also connected to the filter circuit 504 and the load (that is, connected to the load through VOUT shown in the figure).

[0071] Specifically, in the output circuit 403, a first end of the inductor L1 is connected to the enabling circuit 401, the input circuit 402, and the switching power supply chip 404, while a second end of the inductor L1 is connected to a first end of the rectifier circuit 502 and the switching power supply chip 404. A second end of the rectifier circuit 502 is connected to the feedback circuit 405 and the filter circuit 504. More specifically, in one embodiment, a first end of the inductor L1 is connected to a first end of the resistor R6, a first end of the capacitor C3, and an input pin VIN of the switching power supply chip 404, while a second end of the inductor L1 is connected to a switch control pin SW of the switching power supply chip 404.

[0072] The specific type of the rectifier circuit 502 is not exclusive, see Figure 5 In one embodiment, the rectifier circuit 502 includes a diode D1 , which is connected to the switching power supply chip 404 , the inductor L1 , the feedback circuit 405 and the filter circuit 504 .

[0073] Specifically, the anode of the diode D1 is connected to the second end of the inductor L1 and the switch control pin SW of the switching power supply chip 404, and the cathode of the diode D1 is connected to the feedback circuit 405 and the filter circuit 504. It is understood that in other embodiments, the diode D1 can also be replaced by a field effect transistor, and the selection is made based on actual needs.

[0074] Please refer to Figure 5In one embodiment, the filtering circuit 504 includes a capacitor C4, the capacitor C4 is connected to the load and the feedback circuit 405, and the capacitor C4 is grounded.

[0075] Specifically, the solution of this embodiment realizes the filtering function by installing a capacitor C4 in the output circuit 403. The first end of the capacitor C4 is connected to the load and the feedback circuit 405, and the second end of the capacitor C4 is grounded to realize the filtering function of the electric energy flowing into the load.

[0076] It should be noted that the specific type of switching power supply chip 404 is not limited. In the solution of this embodiment, the switching power supply chip 404 is a switching power supply chip 404 of the type that integrates a field-effect transistor. Correspondingly, in other embodiments, a switching power supply chip 404 without an integrated field-effect transistor may also be used. In this case, an additional field-effect transistor is required for the power conversion circuit 104. The drain and source of the field-effect transistor are connected between the inductor L1 and the ground, and the gate of the field-effect transistor is connected to the switching power supply chip 404.

[0077] See also Figure 5 In one embodiment, the feedback circuit 405 includes a resistor R8 and a resistor R9, the resistor R8 is connected to the output circuit 403, the resistor R9, the switching power supply chip 404 and the gear adjustment circuit 106 (that is, connected to the gear adjustment circuit through VFB shown in the figure), and the resistor R9 is grounded.

[0078] Specifically, the solution of this embodiment uses resistors R8 and R9 to form a feedback circuit 405. The first end of resistor R8 is connected to the output circuit 403, the second end of resistor R8 is connected to the first end of resistor R9, the switching power supply chip 404, and the gear adjustment circuit 106, and the second end of resistor R9 is grounded. In more detail, in one embodiment, the first end of resistor R8 is connected to the cathode of diode D1 and the first end of capacitor C4, and the second end of resistor R8 is connected to the first end of resistor R9, the voltage feedback pin FB of the switching power supply chip 404, and the gear adjustment circuit 106.

[0079] See also Figure 6 In one embodiment, the gear adjustment circuit 106 includes a storage circuit 606, a third switch circuit 602, a fourth switch circuit 604, and a second touch switch circuit 608. The third switch circuit 602 is connected to the power conversion circuit 104, the fourth switch circuit 604, the storage circuit 606, and the second touch switch circuit 608. The fourth switch circuit 604 is also connected to the power conversion circuit 104 and the second touch switch circuit 608.

[0080] Specifically, the gear adjustment circuit 106 includes a storage circuit 606, a third switch circuit 602, a fourth switch circuit 604 and a second touch switch circuit 608. During actual operation, by pressing the second touch switch circuit 608, the third switch circuit 602 and the fourth switch circuit 604 can be switched to different operating states, thereby combining with the feedback circuit 405 to change the voltage of the final output load and realize gear adjustment.

[0081] See also Figure 7 In one embodiment, the third switch circuit 602 includes a resistor R10, a resistor R11, a resistor R12, a switch device U2, and a diode D2. The switch device U2 is connected to the resistor R10, the resistor R11, the fourth switch circuit 604, the diode D2, and the resistor R12. The resistor R10 is also connected to the power conversion circuit 104 and the fourth switch circuit 604. The resistor R11 is also connected to the energy storage circuit 606, the diode D2, and the second touch switch circuit 608. The resistor R12 is also connected to the fourth switch circuit 604. The switch device U2 is grounded.

[0082] Specifically, the first end of resistor R10 is connected to the power conversion circuit 104 and the fourth switch circuit 604, the second end of resistor R10 is connected to the input end of the switch device U2 and the fourth switch circuit 604, the first end of resistor R11 is connected to the energy storage circuit 606, the input end of the switch device U2, and the second end of resistor R10, the control end of the switch device U2 is connected to the first end of resistor R12 and the anode of diode D2, the second end of resistor R12 is connected to the fourth switch circuit 604, the cathode of diode D2 is connected to the second touch switch circuit 608 and the second end of resistor R11, and the second end of the switch device U2 is grounded. More specifically, in one embodiment, the first end of resistor R10 is connected to the second end of resistor R8 and the first end of resistor R9, that is, the third switch circuit 602 is connected to the power management chip through the feedback circuit 405, thereby realizing the feedback adjustment operation of the voltage level.

[0083] See also Figure 7 In one embodiment, the fourth switch circuit 604 includes a resistor R13, a resistor R14, a resistor R15, a switch device U3, and a diode D3. The switch device U3 is connected to the resistor R13, the resistor R14, the third switch circuit 602, the diode D3, and the resistor R15. The resistor R13 is also connected to the third switch circuit 602 and the power conversion circuit 104. The resistor R14 is also connected to the diode D3 and the second touch switch circuit 608. The resistor R15 is also connected to the third switch circuit 602. The switch device U3 is grounded.

[0084] Specifically, similar to the above-mentioned third switch circuit 602, the first end of the resistor R13 in the fourth switch circuit 604 is connected to the third switch circuit 602 and the power conversion circuit 104, the second end of the resistor R13 is connected to the first end of the resistor R14, the input end of the switch device U3 and the third switch circuit 602, the first end of the resistor R14 is connected to the input end of the switch device U3, the second end of the resistor R13 and the third switch circuit 602, the control end of the switch device U3 is connected to the first end of the resistor R15 and the anode of the diode D3, the second end of the resistor R15 is connected to the third switch circuit 602, the cathode of the diode D3 is connected to the second touch switch circuit 608 and the second end of the resistor R14, and the second end of the switch device U3 is grounded.

[0085] In more detail, in one embodiment, the first end of the resistor R13 is connected to the first end of the resistor R10, the second end of the resistor R10 and the first end of the resistor R14 are connected to the second end of the resistor R12, and the second end of the resistor R15 is connected to the input end of the switching device U2.

[0086] It can be understood that in one embodiment, in order to ensure that the voltage level output by the power conversion circuit 104 to the load is changed under the control of the second touch switch, the resistor R10 in the third switch circuit 602 and the resistor R13 in the fourth switch circuit 604 are set to different sizes.

[0087] It should be noted that the types of switching devices U2 and U3 are not unique. In one embodiment, field effect transistors can be used. In other embodiments, other types of semiconductor switching devices such as transistors can also be used, without specific limitation.

[0088] See also Figure 7 In one embodiment, the second touch switch circuit 608 includes a touch switch SW2, a resistor R16, a resistor R17, a capacitor C5, and a capacitor C6. The resistor R16 is connected to the capacitor C5, the third switch circuit 602, and the touch switch SW2. The capacitor C5 is also connected to the third switch circuit 602 and the touch switch SW2. The resistor R17 is connected to the fourth switch circuit 604, the capacitor C6, and the touch switch SW2. The capacitor C6 is also connected to the fourth switch circuit 604 and the touch switch SW2. The touch switch SW2 is grounded.

[0089] Specifically, in the second touch switch circuit 608, resistor R16 and capacitor C5 are connected in parallel. Their first common terminal is connected to the third switch circuit 602, and their other common terminal is connected to the first terminal of the touch switch SW2. Resistor R17 and capacitor C6 are connected in parallel. Their first common terminal is connected to the fourth switch circuit 604, and their other common terminal is connected to the first terminal of the touch switch SW2. The second terminal of the touch switch SW2 is grounded. This configuration not only allows voltage level adjustment when a user presses the touch switch SW2, but also forms a key discharge circuit, improving the sensitivity of the touch switch SW2.

[0090] It is understood that the specific type of energy storage circuit 606 is not unique, see Figure 7 In one embodiment, the energy storage circuit 606 includes a capacitor C7, the capacitor C7 is connected to the third switch circuit 602, and the capacitor C7 is grounded.

[0091] Specifically, a first end of the capacitor C7 is connected to the third switch circuit 602 , specifically to a first end of the resistor R11 in the third switch circuit 602 , and a second end of the capacitor C7 is grounded.

[0092] To facilitate understanding of the gear switching function of the gear adjustment circuit 106, the present application is explained below with reference to a more detailed embodiment. In this embodiment, the third switch circuit 602 includes resistors R10, R11, R12, a switch device U2, and a diode D2; the fourth switch circuit 604 includes resistors R13, R14, R15, a switch device U3, and a diode D3; the second touch switch circuit 608 includes a touch switch SW2, resistors R16, R17, capacitors C5, and C6; and the energy storage circuit 606 includes capacitor C7.

[0093] When the switch control circuit 102 is pressed to connect the power conversion circuit 104 and the power supply, and the load starts working, the first end of the resistor R10 and the first end of the resistor R13 in the gear adjustment circuit 106 are energized, that is, the VFB point shown in the figure is energized. At the moment of energization, due to the presence of capacitor C7, VFB charges capacitor C7 through resistor R10. Due to the characteristic that the voltage across the capacitor cannot change suddenly, the upper end of capacitor C7 generates a momentary low level and is connected to the control end of the switch device U3 (taking the field effect tube as an example, it is the gate at this time) through resistor R14, that is, the gate of the switch device U3 is low, and the control switch device U3 is in the cut-off state. VFB is connected to the control end of the switch device U2 through resistor R13 and resistor R12, that is, the gate of the switch device U2. At this time, the gate of the switch device U2 is high, and the switch device U2 is turned on. Correspondingly, the voltage output to the load by the output circuit 403 is:

[0094] VOUT1=VFB*{1+R8 / [R9*R10 / (R9+R10)]}

[0095] Wherein, VFB is the voltage at the VFB point shown in the figure, and R8, R9 and R10 are the resistance values ​​of resistors R8, R9 and R10 respectively. After the switch device U2 is turned on, the gate of the switch device U3 is connected to the ground through the resistor R15 and the switch device U2, and the switch device U3 remains in the off state. When the touch switch SW2 is pressed, the capacitors C5 and C6 are instantly grounded, the gate voltage of the switch device U2 becomes zero, and the switch device U2 enters the off state, while VFB flows to the gate of the switch device U3 through the resistor R10, causing the switch device to enter the on state. Accordingly, at this time, the voltage output to the load by the output circuit 403 is:

[0096] VOUT2=VFB*{1+R8 / [R9*R13 / (R9+R13)]}

[0097] Where VFB is the voltage at the VFB point shown in the figure, and R8, R9, and R13 are the resistance values ​​of resistors R8, R9, and R13, respectively. Similarly, when the touch switch SW2 is pressed again, the switch device U3 is turned off and the switch device U2 is turned on. Each time the touch switch SW2 is pressed, the conduction state of the switch devices U2 and U3 is reversed, causing the voltage output by the output circuit 403 to the load to switch back and forth between VOUT2 and VOUT1, thereby adjusting the load operating range.

[0098] Based on the power supply circuit described above, an embodiment of the present application further provides an electrical device, which includes a load and the power supply circuit described above.

[0099] Specifically, the structure and operating principle of the power supply circuit are as shown in the above-mentioned embodiments and the accompanying drawings, and will not be repeated here. For the electrical equipment of this embodiment, when the power supply is connected to the switch control circuit 102, the user can control the switch control circuit 102 to be turned on or off by sending a press signal to the switch control circuit 102, so that the power supply is connected to the power conversion circuit 104, and the power is supplied to the load after conversion by the power conversion circuit 104. During the power supply process, the user can change the voltage level that the power conversion circuit 104 ultimately outputs to the load by sending a press signal to the level adjustment circuit 106, thereby achieving load level adjustment. In the above scheme, the load level adjustment is realized through the hardware circuit, and there is no need to set up an additional main control chip, so there is no need to develop a specific application program. This effectively solves the problem that the level switching in the electrical equipment requires the use of a main control chip equipped with a specific application program, which is difficult to develop.

[0100] It is understandable that the specific type of electrical equipment is not limited. As long as the load has two different gear operation requirements, it can be any equipment, such as handheld fans, hair dryers, humidifiers, shavers, LED lights, etc., without specific limitation.

[0101] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A power supply circuit, characterized in that: include: A switch control circuit, a power conversion circuit, and a gear adjustment circuit, wherein the switch control circuit is used to connect to a power source, the switch control circuit and the gear adjustment circuit are respectively connected to the power conversion circuit, and the power conversion circuit is used to connect to a load; The switch control circuit is used to connect or disconnect the connection between the power conversion circuit and the power supply according to the pressing signal; the gear adjustment circuit is used to change the voltage gear output by the power conversion circuit to the load according to the pressing signal; The switch control circuit includes a voltage divider circuit, a first switch circuit, a second switch circuit and a first touch switch circuit. The voltage divider circuit is connected to the power supply, the first switch circuit, the second switch circuit and the first touch switch circuit. The first switch circuit is also connected to the power supply, the second switch circuit, the first touch switch circuit and the power conversion circuit. The second switch circuit is also connected to the first touch switch circuit.

2. The power supply circuit according to claim 1, wherein: The voltage divider circuit includes a resistor R1 and a resistor R2, wherein the resistor R1 is connected to the first switch circuit, the power supply, and the resistor R2, and the resistor R2 is further connected to the first switch circuit, the second switch circuit, and the first touch switch circuit; And / or, the first switching circuit includes a switching device U1 and a resistor R3, the switching device U1 is connected to the power supply, the voltage divider circuit, the power conversion circuit and the resistor R3, and the resistor R3 is also connected to the first touch switch circuit and the second switching circuit.

3. The power supply circuit according to claim 1, wherein: The second switch circuit includes a switch device Q1, the switch device Q1 is connected to the voltage divider circuit, the first touch switch circuit and the first switch circuit, and the switch device Q1 is grounded; And / or, the first touch switch circuit includes a touch switch SW1, a capacitor C1, a capacitor C2, a resistor R4 and a resistor R5, the resistor R4 is connected to the voltage divider circuit, the second switch circuit, the touch switch SW1 and the capacitor C1, the touch switch SW1 is also connected to the capacitor C1, the capacitor C2 and the resistor R5, the resistor R5 is also connected to the second switch circuit and the first switch circuit, and the capacitor C1, the capacitor C2 and the resistor R5 are grounded.

4. The power supply circuit according to any one of claims 1 to 3, wherein: The power conversion circuit includes an enabling circuit, an input circuit, an output circuit, a feedback circuit and a switching power supply chip. The enabling circuit is connected to the switching control circuit, the input circuit and the switching power supply chip. The input circuit is also connected to the switching control circuit, the switching power supply chip and the output circuit. The output circuit is also connected to the switching power supply chip, the feedback circuit and the load. The feedback circuit is also connected to the switching power supply chip and the gear adjustment circuit.

5. The power supply circuit according to claim 4, wherein: The enabling circuit includes a resistor R6 and a resistor R7, wherein the resistor R6 is connected to the switch control circuit, the input circuit, the switch power supply chip and the resistor R7, and the resistor R7 is grounded; And / or, the input circuit includes a capacitor C3, the capacitor C3 is connected to the enabling circuit, the switch control circuit, the output circuit and the switching power supply chip, and the capacitor C3 is grounded.

6. The power supply circuit according to claim 4, wherein: The output circuit includes an inductor L1, a rectifier circuit and a filter circuit. The inductor L1 is connected to the enable circuit, the input circuit, the switching power supply chip and the rectifier circuit. The rectifier circuit is also connected to the switching power supply chip, the feedback circuit and the filter circuit. The feedback circuit is also connected to the filter circuit and the load.

7. The power supply circuit according to claim 6, wherein: The rectifier circuit includes a diode D1, and the diode D1 is connected to the switching power supply chip, the inductor L1, the feedback circuit and the filter circuit; And / or, the filtering circuit includes a capacitor C4, the capacitor C4 is connected to the load and the feedback circuit, and the capacitor C4 is grounded.

8. The power supply circuit according to claim 4, wherein: The feedback circuit includes a resistor R8 and a resistor R9. The resistor R8 is connected to the output circuit, the resistor R9, the switching power supply chip and the gear adjustment circuit. The resistor R9 is grounded.

9. The power supply circuit according to any one of claims 1 to 3, characterized in that: The gear adjustment circuit includes an energy storage circuit, a third switch circuit, a fourth switch circuit and a second touch switch circuit. The third switch circuit is connected to the power conversion circuit, the fourth switch circuit, the energy storage circuit and the second touch switch circuit. The fourth switch circuit is also connected to the power conversion circuit and the second touch switch circuit.

10. The power supply circuit according to claim 9, wherein: The third switch circuit includes a resistor R10, a resistor R11, a resistor R12, a switch device U2 and a diode D2. The switch device U1 is connected to the resistor R10, the resistor R11, the fourth switch circuit, the diode D2 and the resistor R12. The resistor R10 is also connected to the power conversion circuit and the fourth switch circuit. The resistor R11 is also connected to the energy storage circuit, the diode D2 and the second touch switch circuit. The resistor R12 is also connected to the fourth switch circuit. The switch device U2 is grounded. And / or, the fourth switching circuit includes a resistor R13, a resistor R14, a resistor R15, a switching device U3 and a diode D3, the switching device U3 connects the resistor R13, the resistor R14, the third switching circuit, the diode D3 and the resistor R15, the resistor R13 is also connected to the third switching circuit and the power conversion circuit, the resistor R14 is also connected to the diode D3 and the second touch switch circuit, the resistor R15 is also connected to the third switching circuit, and the switching device U3 is grounded.

11. The power supply circuit according to claim 9, wherein: The second touch switch circuit includes a touch switch SW2, a resistor R16, a resistor R17, a capacitor C5, and a capacitor C6. The resistor R16 is connected to the capacitor C5, the third switch circuit, and the touch switch SW2. The capacitor C5 is also connected to the third switch circuit and the touch switch SW2. The resistor R17 is connected to the fourth switch circuit, the capacitor C6, and the touch switch SW2. The capacitor C6 is also connected to the fourth switch circuit and the touch switch SW2. The touch switch SW2 is grounded.

12. The power supply circuit according to claim 9, wherein: The energy storage circuit includes a capacitor C7 , which is connected to the third switch circuit and grounded.

13. An electrical device, characterized in that: The invention comprises a load and the power supply circuit according to any one of claims 1 to 12.

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