Direct-current brushless ceiling fan speed regulation circuit based on single live wire

Abstract

The utility model relates to the technical field of single live wires, in particular to a direct current brushless ceiling fan speed regulation circuit based on a single live wire, which comprises a chopping unit and a single live wire electricity taking unit which are electrically connected with a live wire of an alternating current circuit, and a speed regulation unit electrically connected with a control unit, the chopping unit is used for receiving the control signal of the control unit, carrying out chopping processing on the alternating current, and outputting a chopped signal through a live wire of an alternating current line; the single-live-wire electricity taking unit is used for voltage electricity taking in a single-live-wire environment; the speed regulation unit is used for outputting different high and low level signals to the control unit; the control unit is used for receiving different high and low level signals and sending different control signals to the chopping unit. According to the utility model, under the condition that a client does not need to change the wiring environment of household electricity, a traditional mechanical switch can be completely replaced, and the state of the ceiling fan can be directly controlled through a single-live-wire inflow control switch and a single-live-wire outflow control signal.

Description

Technical Field

[0001] The utility model relates to the technical field of single live wires, in particular to a DC brushless ceiling fan speed regulating circuit based on a single live wire. Background Art

[0002] In traditional household power environments, based on safety and cost considerations, the control method of mechanical switches is to introduce only one live wire to the switch location. The control switch and the control board are independent in space, and the use scenario does not have an AC neutral wire, which makes it inconvenient to control the working state of the ceiling fan in a low-cost manner without adding additional wires. In the prior art, to achieve this goal, either additional wiring is required or wireless RF transmission remote control is used, which is relatively complicated and costly. Utility Model Content

[0003] The purpose of the utility model is to propose a DC brushless ceiling fan speed regulation circuit based on a single live wire, which can completely replace the traditional mechanical switch without changing the wiring environment of household electricity consumption. The control switch is controlled by the single live wire, and the control signal flows out of the single live wire to directly control the state of the ceiling fan.

[0004] To achieve this purpose, the utility model adopts the following technical solutions:

[0005] A DC brushless ceiling fan speed regulation circuit based on a single live wire comprises a chopper unit, a single live wire power supply unit, a control unit and a speed regulation unit;

[0006] The input end and the output end of the chopping unit are both electrically connected to the live wire of the AC line, the chopping unit is electrically connected to the control unit, the chopping unit is used to receive the control signal of the control unit and chop the AC power, and output the chopped signal through the live wire of the AC line;

[0007] The input end of the single live wire power taking unit is electrically connected to the live wire of the AC line, the output end of the single live wire power taking unit is electrically connected to the control unit, and the single live wire power taking unit is used to take voltage power in a single live wire environment;

[0008] The control unit is electrically connected to the speed regulating unit respectively, and the speed regulating unit is used to output different high and low level signals to the control unit;

[0009] The control unit is used to receive different high and low level signals from the speed regulating unit and send different control signals to the chopping unit.

[0010] Preferably, the chopper unit includes a thyristor SCR1, a resistor R4, a resistor R2, a resistor R3, a resistor R5, a transistor Q3 and a diode D1;

[0011] One end of the resistor R4 is connected to a 10V voltage, and the other end of the resistor R4 is electrically connected to the collector of the transistor Q3 and the control stage of the unidirectional thyristor SCR1 respectively;

[0012] The base of the transistor Q3 is electrically connected to one end of the resistor R2 and one end of the resistor R3 respectively, the other end of the resistor R2 is electrically connected to the control unit 3, and the emitter of the transistor Q3 and the other end of the resistor R3 are both grounded;

[0013] The anode of the unidirectional thyristor SCR1 is electrically connected to the single live wire power supply unit 2, the positive electrode of the diode D1 and one end of the resistor R5 respectively, the cathode of the unidirectional thyristor SCR1 and the other end of the resistor R5 are electrically connected to the live wire input end of the AC line through the inductor L1, and the cathode of the diode D1 is electrically connected to the live wire output end of the AC line.

[0014] Preferably, the single live wire power taking unit includes a bidirectional thyristor SCR2, a resistor R1, a capacitor C2, a voltage regulator tube Z1, a diode D2, a diode D3 and an electrolytic capacitor C1;

[0015] The T2 pole of the bidirectional thyristor SCR2, one end of the resistor R1, one end of the capacitor C2 and one end of the electrolytic capacitor C1 are all electrically connected to the live wire input end of the AC line through the inductor L1 and are grounded. The T1 pole of the bidirectional thyristor SCR2 is electrically connected to the negative pole of the diode D2, the positive pole of the diode D3 and the negative pole of the voltage regulator Z1 respectively. The control pole of the bidirectional thyristor SCR2 is electrically connected to the other end of the resistor R1, the other end of the capacitor C2 and the positive pole of the voltage regulator Z1. The other end of the electrolytic capacitor C1 is electrically connected to the negative pole of the diode D3 and outputs a 10V voltage.

[0016] Preferably, the control unit includes a voltage reduction subunit, a control subunit, a key subunit, an indication subunit and a connection subunit;

[0017] The step-down subunit is used to convert the 10V voltage obtained by the single live wire power supply unit into a 3.3V voltage to supply power to the control subunit, the button subunit, the indication subunit and the connection subunit;

[0018] The control subunit is electrically connected to the key subunit and the indication subunit respectively. The key subunit is used to receive different high and low level signals from the speed regulation unit to the control subunit. The indication subunit is used to indicate the key status of the key subunit. The control subunit will receive different high and low level signals from the speed regulation unit and send different control signals to the chopping unit.

[0019] Preferably, the step-down subunit includes a step-down chip U4 and a capacitor C11;

[0020] The third end of the step-down chip U4 is electrically connected to the chopper unit and the single live wire power supply unit respectively;

[0021] The first end of the step-down chip U4 is electrically connected to one end of the capacitor C11 and outputs a 3.3V voltage to the control subunit 32 and the key subunit 33;

[0022] The second end of the step-down chip U4 and the other end of the capacitor C11 are both grounded.

[0023] Preferably, the control subunit includes a control chip U3;

[0024] The second end of the control chip U3 is electrically connected to the chopping unit;

[0025] The third terminal of the control chip U3 is electrically connected to the indicating subunit;

[0026] The 4th terminal, the 7th terminal and the 14th terminal of the control chip U3 are all electrically connected to the connecting subunit;

[0027] The 5th, 9th, 10th, 11th, 12th, 13th, 15th and 16th terminals of the control chip U3 are all electrically connected to the key subunit;

[0028] The sixth terminal of the control chip U3 is grounded;

[0029] The 8th terminal of the control chip U3 is connected to a 3.3V voltage.

[0030] Preferably, the model of the control chip U3 is ATM8F8040.

[0031] Preferably, the button subunit includes a socket CON2 and 8 pull-up resistors;

[0032] The speed regulating unit 4 includes 8 buttons;

[0033] One end of the 8 buttons is respectively connected to the ground signal, the other end of the 8 buttons is respectively electrically connected to the control chip U3 through a 3.3V pull-up resistor, and the other end of the 8 buttons is respectively electrically connected to the 2nd to 9th ends of the socket CON2;

[0034] The first end of the socket CON2 is grounded;

[0035] The 10th terminal of the socket CON2 is electrically connected to the control chip U3 and the indicating subunit respectively.

[0036] Preferably, the indicating subunit includes a resistor R11 and an indicator light LED1;

[0037] One end of the resistor R11 is electrically connected to the control chip U3 , the other end of the resistor R11 is electrically connected to one end of the indicator light LED1 , and the other end of the indicator light LED1 is grounded.

[0038] One of the above technical solutions has the following beneficial effects: the single live wire power supply unit takes voltage power in a single live wire environment and supplies power to the control unit, the control unit is electrically connected to the chopping unit and the speed regulating unit respectively, and the control unit converts the different high and low level signals received from the speed regulating unit into corresponding control signals and sends them to the chopping unit to control the on and off of the chopping unit. Since the chopping unit is connected in series to the single live wire, a control signal composed of intermittent AC signals loaded on the single live wire is formed, and the control signal is directly transmitted through the single live wire to realize the function of controlling the state of the ceiling fan, which is more intelligent than the single live wire ceiling fan switch solution on the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the principle of a DC brushless ceiling fan speed regulation circuit based on a single live wire in the utility model;

[0040] Figure 2 This is a schematic diagram of the structure of a DC brushless ceiling fan speed regulation circuit based on a single live wire in the utility model;

[0041] Figure 3 This is a working diagram of a DC brushless ceiling fan speed regulation circuit based on a single live wire in the utility model;

[0042] In the attached drawings: a chopper unit 1 , a single live wire power supply unit 2 , a control unit 3 , a speed regulating unit 4 , a voltage reduction subunit 31 , a control subunit 32 , a button subunit 33 , an indication subunit 34 , and a connection subunit 35 . DETAILED DESCRIPTION

[0043] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, the meaning of "plurality" is two or more.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] like Figure 1-3 As shown, a DC brushless ceiling fan speed control circuit based on a single live wire includes a chopper unit 1, a single live wire power supply unit 2, a control unit 3 and a speed control unit 4;

[0048] The input end and the output end of the chopping unit 1 are both electrically connected to the live wire of the AC line, and the chopping unit 1 is electrically connected to the control unit 3. The chopping unit 1 is used to receive the control signal of the control unit 3 and perform chopping processing on the AC power, and output the chopped signal through the live wire of the AC line;

[0049] The input end of the single live wire power taking unit 2 is electrically connected to the live wire of the AC line, and the output end of the single live wire power taking unit 2 is electrically connected to the control unit 3. The single live wire power taking unit 2 is used to take voltage power in a single live wire environment;

[0050] The control unit 3 is electrically connected to the speed regulating unit 4 respectively, and the speed regulating unit 4 is used to output different high and low level signals to the control unit 3;

[0051] The control unit 3 is used to receive different high and low level signals from the speed regulating unit 4 and send different control signals to the chopping unit 1 .

[0052] In the present invention, the single live wire power supply unit 2 takes voltage power in a single live wire environment and supplies power to the control unit 3. The control unit 3 is electrically connected to the chopping unit 1 and the speed regulating unit 4 respectively. The control unit 3 converts the different high and low level signals received from the speed regulating unit 4 into corresponding control signals and sends them to the chopping unit 1 to control the on and off of the chopping unit 1. Since the chopping unit 1 is connected in series to the single live wire, a control signal composed of intermittent AC signals loaded on the single live wire is formed. The control signal is directly transmitted through the single live wire to realize the function of controlling the state of the ceiling fan, which is more intelligent than the single live wire ceiling fan switch solution on the market.

[0053] To further illustrate, the chopper unit 1 includes a thyristor SCR1, a resistor R4, a resistor R2, a resistor R3, a resistor R5, a transistor Q3 and a diode D1;

[0054] One end of the resistor R4 is connected to a 10V voltage, and the other end of the resistor R4 is electrically connected to the collector of the transistor Q3 and the control stage of the unidirectional thyristor SCR1 respectively;

[0055] The base of the transistor Q3 is electrically connected to one end of the resistor R2 and one end of the resistor R3 respectively, the other end of the resistor R2 is electrically connected to the control unit 3, and the emitter of the transistor Q3 and the other end of the resistor R3 are both grounded;

[0056] The anode of the unidirectional thyristor SCR1 is electrically connected to the single live wire power supply unit 2, the positive electrode of the diode D1 and one end of the resistor R5 respectively, the cathode of the unidirectional thyristor SCR1 and the other end of the resistor R5 are electrically connected to the live wire input end of the AC line through the inductor L1, and the cathode of the diode D1 is electrically connected to the live wire output end of the AC line.

[0057] When there is no key action, the ON / OFF control signal output by the control unit 3 defaults to a long low level state, so that the transistor Q3 is in a disconnected state; and the unidirectional thyristor SCR1 is in a conductive state due to its control electrode input high level, and the alternating current can pass normally; when receiving different high and low level signals from the speed regulation unit 4, the control unit 3 will control the ON / OFF signal to output a corresponding high level signal according to the corresponding high and low level signals to turn on the transistor Q3, thereby controlling the unidirectional thyristor SCR1 to turn off to achieve fast chopping processing of the alternating current, which has the advantages of fast speed and short response time, making the circuit very efficient and reliable.

[0058] To further illustrate, the single live wire power taking unit 2 includes a bidirectional thyristor SCR2, a resistor R1, a capacitor C2, a voltage regulator tube Z1, a diode D2, a diode D3 and an electrolytic capacitor C1;

[0059] The T2 pole of the bidirectional thyristor SCR2, one end of the resistor R1, one end of the capacitor C2 and one end of the electrolytic capacitor C1 are all electrically connected to the live wire input end of the AC line through the inductor L1 and are grounded. The T1 pole of the bidirectional thyristor SCR2 is electrically connected to the negative pole of the diode D2, the positive pole of the diode D3 and the negative pole of the voltage regulator Z1 respectively. The control pole of the bidirectional thyristor SCR2 is electrically connected to the other end of the resistor R1, the other end of the capacitor C2 and the positive pole of the voltage regulator Z1. The other end of the electrolytic capacitor C1 is electrically connected to the negative pole of the diode D3 and outputs a 10V voltage.

[0060] The resistor R1 and the capacitor C2 play a filtering role, and the voltage regulator Z1 is used to limit the output voltage value of the switch to less than 10V when it is working and drawing power, thereby solving the problem of the single-live-wire thyristor switch in the prior art generating serious electromagnetic interference due to excessively high output voltage when drawing power when working.

[0061] To further illustrate, the control unit 3 includes a voltage reduction subunit 31, a control subunit 32, a key subunit 33, an indication subunit 34 and a connection subunit 35;

[0062] The step-down subunit 31 is used to convert the 10V voltage obtained by the single live wire power supply unit 2 into a 3.3V voltage to supply power to the control subunit 32, the button subunit 33, the indication subunit 34 and the connection subunit 35;

[0063] The control subunit 32 is electrically connected to the key subunit 33 and the indication subunit 34 respectively. The key subunit 33 is used to receive different high and low level signals of the speed regulation unit 4 to the control subunit 32. The indication subunit 34 is used to indicate the key status of the key subunit 33. The control subunit 32 will receive different high and low level signals of the speed regulation unit 4 and send different control signals to the chopping unit 1.

[0064] To further illustrate, the buck subunit 31 includes a buck chip U4 and a capacitor C11;

[0065] The third end of the step-down chip U4 is electrically connected to the chopper unit 1 and the single live wire power supply unit 2 respectively;

[0066] The first end of the step-down chip U4 is electrically connected to one end of the capacitor C11 and outputs a 3.3V voltage to the control subunit 32 and the key subunit 33;

[0067] The second end of the step-down chip U4 and the other end of the capacitor C11 are both grounded.

[0068] The step-down chip U4 and the capacitor C11 form a step-down circuit to convert the voltage obtained from the single live wire into a 3.3V voltage to supply power to the control chip U3, so as to meet the voltage requirement of the control chip U3.

[0069] To further illustrate, the control subunit 32 includes a control chip U3;

[0070] The second end of the control chip U3 is electrically connected to the chopping unit 1;

[0071] The third terminal of the control chip U3 is electrically connected to the indicating subunit 34;

[0072] The 4th terminal, the 7th terminal and the 14th terminal of the control chip U3 are all electrically connected to the connecting subunit 35;

[0073] The 5th, 9th, 10th, 11th, 12th, 13th, 15th and 16th terminals of the control chip U3 are all electrically connected to the key subunit 33;

[0074] The sixth terminal of the control chip U3 is grounded;

[0075] The 8th terminal of the control chip U3 is connected to a 3.3V voltage.

[0076] To further explain, the model of the control chip U3 is ATM8F8040.

[0077] Specifically, when the speed regulating unit 4 is used to generate high and low level signals, the control chip U3 detects the high and low level changes of the corresponding pins, decodes the high and low level changes, and sends out corresponding control signals to implement corresponding functions.

[0078] To further illustrate, the key subunit 33 includes a socket CON2 and 8 pull-up resistors;

[0079] The speed regulating unit 4 includes 8 buttons;

[0080] One end of the 8 buttons is respectively connected to the ground signal, the other end of the 8 buttons is respectively electrically connected to the control chip U3 through a 3.3V pull-up resistor, and the other end of the 8 buttons is respectively electrically connected to the 2nd to 9th ends of the socket CON2;

[0081] The first end of the socket CON2 is grounded;

[0082] The 10th terminal of the socket CON2 is electrically connected to the control chip U3 and the indicating subunit 34 respectively.

[0083] Specifically, Figure 2As shown, the eight buttons are button S1, button S2, button S3, button S4, button S5, button S6, button S7 and button S8;

[0084] The eight pull-up resistors are resistor R33, resistor R32, resistor R31, resistor R30, resistor R29, resistor R28, resistor R27, resistor R26 and resistor R25.

[0085] It should be noted that the speed regulating unit 4 can be a combination of one or more switches such as pull cord control, toggle switch control or button control, and can generate an action signal, a toggle signal or a button signal through a pull cord, a toggle switch or a button switch.

[0086] To further illustrate, the indicating subunit 34 includes a resistor R11 and an indicator LED1;

[0087] One end of the resistor R11 is electrically connected to the control chip U3 , the other end of the resistor R11 is electrically connected to one end of the indicator light LED1 , and the other end of the indicator light LED1 is grounded.

[0088] The key signal input pins of the control chip U3 default to high-level signals when there is no key action. When a key action is received, the corresponding pin input of the chip becomes a low-level signal, and the indicator LED1 will light up as a prompt.

[0089] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementations of the present invention without creative work, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A DC brushless ceiling fan speed control circuit based on a single live wire, characterized in that: It includes a chopper unit, a single live wire power supply unit, a control unit and a speed regulating unit; The input end and the output end of the chopping unit are both electrically connected to the live wire of the AC line, the chopping unit is electrically connected to the control unit, the chopping unit is used to receive the control signal of the control unit and chop the AC power, and output the chopped signal through the live wire of the AC line; The input end of the single live wire power taking unit is electrically connected to the live wire of the AC line, the output end of the single live wire power taking unit is electrically connected to the control unit, and the single live wire power taking unit is used to take voltage power in a single live wire environment; The control unit is electrically connected to the speed regulating unit respectively, and the speed regulating unit is used to output different high and low level signals to the control unit; The control unit is used to receive different high and low level signals from the speed regulating unit and send different control signals to the chopping unit.

2. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 1, characterized in that: The chopper unit includes a thyristor SCR1, a resistor R4, a resistor R2, a resistor R3, a resistor R5, a transistor Q3 and a diode D1; One end of the resistor R4 is connected to a 10V voltage, and the other end of the resistor R4 is electrically connected to the collector of the transistor Q3 and the control stage of the unidirectional thyristor SCR1 respectively; The base of the transistor Q3 is electrically connected to one end of the resistor R2 and one end of the resistor R3 respectively, the other end of the resistor R2 is electrically connected to the control unit 3, and the emitter of the transistor Q3 and the other end of the resistor R3 are both grounded; The anode of the unidirectional thyristor SCR1 is electrically connected to the single live wire power supply unit 2, the positive electrode of the diode D1 and one end of the resistor R5 respectively, the cathode of the unidirectional thyristor SCR1 and the other end of the resistor R5 are electrically connected to the live wire input end of the AC line through the inductor L1, and the cathode of the diode D1 is electrically connected to the live wire output end of the AC line.

3. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 1, characterized in that: The single live wire power supply unit includes a bidirectional thyristor SCR2, a resistor R1, a capacitor C2, a voltage regulator tube Z1, a diode D2, a diode D3 and an electrolytic capacitor C1; The T2 pole of the bidirectional thyristor SCR2, one end of the resistor R1, one end of the capacitor C2 and one end of the electrolytic capacitor C1 are all electrically connected to the live wire input end of the AC line through the inductor L1 and are grounded. The T1 pole of the bidirectional thyristor SCR2 is electrically connected to the negative pole of the diode D2, the positive pole of the diode D3 and the negative pole of the voltage regulator Z1 respectively. The control pole of the bidirectional thyristor SCR2 is electrically connected to the other end of the resistor R1, the other end of the capacitor C2 and the positive pole of the voltage regulator Z1. The other end of the electrolytic capacitor C1 is electrically connected to the negative pole of the diode D3 and outputs a 10V voltage.

4. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 1, characterized in that: The control unit includes a voltage reduction subunit, a control subunit, a key subunit, an indication subunit and a connection subunit; The step-down subunit is used to convert the 10V voltage obtained by the single live wire power supply unit into a 3.3V voltage to supply power to the control subunit, the button subunit, the indication subunit and the connection subunit; The control subunit is electrically connected to the key subunit and the indication subunit respectively. The key subunit is used to receive different high and low level signals from the speed regulation unit to the control subunit. The indication subunit is used to indicate the key status of the key subunit. The control subunit will receive different high and low level signals from the speed regulation unit and send different control signals to the chopping unit.

5. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 4, characterized in that: The buck subunit includes a buck chip U4 and a capacitor C11; The third end of the step-down chip U4 is electrically connected to the chopper unit and the single live wire power supply unit respectively; The first end of the step-down chip U4 is electrically connected to one end of the capacitor C11 and outputs a 3.3V voltage to the control subunit 32 and the key subunit 33; The second end of the step-down chip U4 and the other end of the capacitor C11 are both grounded.

6. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 5, characterized in that: The control subunit includes a control chip U3; The second end of the control chip U3 is electrically connected to the chopping unit; The third terminal of the control chip U3 is electrically connected to the indicating subunit; The 4th terminal, the 7th terminal and the 14th terminal of the control chip U3 are all electrically connected to the connecting subunit; The 5th, 9th, 10th, 11th, 12th, 13th, 15th and 16th terminals of the control chip U3 are all electrically connected to the key subunit; The sixth terminal of the control chip U3 is grounded; The 8th terminal of the control chip U3 is connected to a 3.3V voltage.

7. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 6, characterized in that: The model of the control chip U3 is ATM8F8040.

8. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 6, characterized in that: The key subunit includes a socket CON2 and 8 pull-up resistors; The speed regulating unit 4 includes 8 buttons; One end of the 8 buttons is respectively connected to the ground signal, the other end of the 8 buttons is respectively electrically connected to the control chip U3 through a 3.3V pull-up resistor, and the other end of the 8 buttons is respectively electrically connected to the 2nd to 9th ends of the socket CON2; The first end of the socket CON2 is grounded; The 10th terminal of the socket CON2 is electrically connected to the control chip U3 and the indicating subunit respectively.

9. A DC brushless ceiling fan speed control circuit based on a single live wire according to claim 6, characterized in that: The indicating subunit includes a resistor R11 and an indicator light LED1; One end of the resistor R11 is electrically connected to the control chip U3 , the other end of the resistor R11 is electrically connected to one end of the indicator light LED1 , and the other end of the indicator light LED1 is grounded.

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