LED light string control system

Abstract

The present invention discloses a light emitting diode light string control system, comprising: a switch unit, having a power input terminal, a power output terminal and a controlled terminal, the power output terminal being connected to the light emitting diode light string; a control unit, the control unit being connected to the controlled terminal of the switch unit; and a second power generating unit, the second power generating unit being connected to the light emitting diode light string. The present invention loads the light emitting control command sent by the control unit to the power line of the light emitting diode in a carrier mode to drive the light emitting diode light string to change, thereby saving costs and simplifying the control circuit of the light emitting diode; the short circuit protection unit detects whether the light emitting diode is short-circuited in real time, has a fast protection response speed when the light emitting diode light string is short-circuited, requires fewer components, has a low production cost, has a simple circuit, is easy to implement, and is safe and reliable.

Description

Technical Field

[0001] The invention relates to the field of lighting control, in particular to a light emitting diode lamp string control system. Background Art

[0002] LED light strings are widely used by users on building exteriors, trees, signs and landscapes to enhance the appearance. At present, they can be roughly divided into two connection methods: series and parallel. The series LED light string is to connect multiple LEDs in series. Although the series connection method makes the LED light string module easy to produce, during use, as long as one LED fails, the current will not be transmitted, causing the entire diode light string to be unable to light up. The parallel LED light string is to connect multiple LEDs in parallel. Each LED light string has a number of LEDs. In order to achieve the synchronous, asynchronous or point control effect of the LED light string, each LED connected to each LED light string will have an addressing code, and each LED must have a control line and an addressing line to control it. If 10 LEDs are connected in parallel, 10 control lines and 10 addressing lines must be used to control the 10 LEDs. The more LEDs are connected in parallel, the more control lines and addressing lines there are, which makes the circuit complex, difficult to manufacture, and costly.

[0003] Chinese invention patent 201510402773.7 discloses a light emitting diode light string control system, wherein the light emitting diode driving device comprises a switch unit, a control unit and a voltage level generating unit, the switch unit is electrically connected to the light emitting diode light string, the control unit is electrically connected to the switch unit, the voltage level generating unit is electrically connected to the output end of the light emitting diode driving device and the light emitting diode light string, the Zener diode ZD of the voltage level generating unit is connected in parallel with the capacitor C, the cathode of the Zener diode ZD is connected in series with the resistor R5 and then connected to the input end after the AC power is rectified and the anode of the series diode D and then electrically connected to the light emitting diode light string, the anode of the Zener diode ZD is grounded, and the Zener diode ZD determines the output voltage value of the voltage level generating unit. When the output voltage of the voltage level generating unit is not high, for example, 3~6V, there are few Zener diodes that meet the requirements, and the Zener diodes below 6V belong to Zener breakdown, and the voltage stabilization characteristics are not as good as avalanche breakdown. When a series-connected LED light string has a short circuit fault, the line current increases, which can easily burn out the LED light string and the power supply, or even cause a dangerous fire, creating a safety hazard. Current LED light strings usually have a short-circuit protection circuit at the output end, but the short-circuit protection circuit is relatively complex and requires many components. Although it can avoid safety hazards, when the short-circuit fault of the light string is resolved, the LED light string control system cannot resume normal operation on its own and can only be discarded, wasting resources. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned existing parallel LED light string circuits, such as being complex, difficult to manufacture, high in cost, and unable to automatically recover after a fault is cleared, the applicant provides a light emitting diode light string control system with a rational structure, thereby reducing the use of transmission lines, having simple circuits, high safety, and being able to automatically recover after a fault is cleared.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A light emitting diode lamp string control system, comprising:

[0007] The switch unit has a power input terminal, a power output terminal and a controlled terminal, and the power output terminal is connected to the light emitting diode light string;

[0008] A control unit, the control unit is connected to a controlled end of the switch unit;

[0009] A second power generation unit, the second power generation unit is connected to the light emitting diode light string;

[0010] When there is no light pulse signal to be transmitted, the control unit controls the switch unit to be turned on, and the power unit transmits a DC power with a first voltage to the light emitting diode light string to drive the light emitting diode light string to emit light; when the light pulse signal generated by the control unit is to be transmitted, the control unit controls the on and off action of the switch unit, and when the control unit controls the switch unit to be turned off, the DC power with a second voltage of the second power generating unit is transmitted to the light emitting diode light string; the second voltage is less than the first voltage.

[0011] As a further improvement of the above technical solution:

[0012] It also includes a short-circuit protection unit, which connects the LED light string and the LED light string; the short-circuit protection unit detects the voltage value at the cathode end of the LED light string, and when the voltage value is greater than the critical value, the short-circuit protection unit sends a second protection signal, and the control unit controls the switch unit to cut off; when the existing voltage is less than the critical value, the short-circuit protection unit sends a first protection signal or does not send a signal.

[0013] It also includes a short circuit protection unit, which includes:

[0014] A third resistor R3, the third resistor R3 is connected to the cathode end of the light emitting diode lamp string;

[0015] A fourth resistor R4, the fourth resistor R4 is connected to the base of the transistor Q2 and the third resistor R3;

[0016] The transistor Q2 has a collector connected to the control unit.

[0017] The short circuit protection unit further includes a second resistor R2, and two ends of the second resistor R2 are respectively connected to the collector of the transistor Q2 and the power supply unit.

[0018] The second power generation unit comprises:

[0019] A first resistor R1, the first resistor R1 is connected to the power supply unit;

[0020] Capacitor C2, capacitor C2 is connected to the first resistor R1;

[0021] A diode D1, wherein the diode D1 is connected to the first resistor R1 and the power output terminal;

[0022] A voltage stabilizing element is connected to the first resistor R1.

[0023] The voltage stabilizing element is a light emitting diode LED1.

[0024] The utility model also comprises a wireless receiving unit, which is connected to the control unit and the power supply unit, and is connected to an external remote controller through radio waves or infrared rays.

[0025] It also includes a storage unit, which is connected to the control unit and stores the address code and color code of the light emitting diode light string.

[0026] The switch unit is a field effect tube, and the control unit includes a microprocessor.

[0027] The beneficial effects of the present invention are as follows:

[0028] The present invention loads the light control command sent by the control unit to the power line of the light emitting diode in a carrier mode to realize the driving of the light emitting diode light string to change the light, so that a plurality of light emitting diodes connected in parallel can be operated synchronously or in a point-controlled manner without the need for additional signal transmission lines, thus saving costs and simplifying the control circuit of the light emitting diode. The light emitting diode with a forward voltage drop range of 1.6 to 3V is used in the second power generation unit, which has a wide selection range, is economical and effective, and has good voltage stabilization characteristics. The light emitting diode plays a fault prompt role when the light string is short-circuited, and its noise is smaller than that of the Zener diode.

[0029] The short-circuit protection unit of the present invention detects in real time whether the light-emitting diode is short-circuited, and has a fast protection response speed when the light-emitting diode light string is short-circuited. Once a short-circuit fault is detected, the short-circuit protection unit sends a low-level second protection signal to the control unit, and the control unit controls the switch unit to be cut off, and the light-emitting diode light string is disconnected from the DC power supply with the first voltage in time, protecting the remaining light-emitting diodes and the power supply unit, thereby reducing maintenance costs and economic losses; when the short-circuit fault is removed, the light-emitting diode light string can produce luminous changes in time according to the luminous pulse signal of the control unit, so as to realize the rapid and normal operation of the light-emitting diode light string control system, reduce maintenance work, and improve resource utilization. The short-circuit protection unit only needs one transistor and two resistors to be realized, requires few components, has low production cost, simple circuit, is easy to realize, and is safe and reliable.

[0030] The invention can be remotely controlled and can freely adjust the brightness, color and light emission change of the light emitting diode lamp string.

[0031] The invention has simple circuit, reliable performance, low production cost and high utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the present invention.

[0033] Figure 2 It is a circuit diagram of the present invention.

[0034] In the figure: 1. LED light string; 2. short circuit protection unit; 3. second power generation unit; 4. switch unit; 41. power input terminal; 42. power output terminal; 43. controlled terminal; 5. control unit; 6. LED light string control system; 7. power supply unit; 8. storage unit; 9. wireless receiving unit. DETAILED DESCRIPTION

[0035] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0036] like Figure 1As shown, the LED light string control system 6 of the present invention is connected to the LED light string 1 and the power supply unit 7. The power supply unit 7 provides a DC voltage to the LED light string control system 6. The LED light string 1 includes a plurality of LEDs connected in parallel, each of which has an address code. The LED light string control system 6 includes a switch unit 4, a control unit 5 and a second power supply generating unit 3, wherein the switch unit 4 has a power input terminal 41, a power output terminal 42 and a controlled terminal 43, the power input terminal 41 is connected to the power supply unit 7, the power output terminal 42 is connected to the anode end of the LED light string 1, the control unit 5 generates a light pulse signal, the control unit 5 is connected to the controlled end 43 of the switch unit 4, and the second power supply generating unit 3 is connected to the LED light string 1 and the power supply unit 7. It also includes a short circuit protection unit 2, which is connected to the control unit 5 and the cathode end of the LED light string 1. It also includes a storage unit 8, which is connected to the control unit 5, and the storage unit 8 stores the address code and color code of the LED light string 1, and the last light pattern used before the control unit 5 is shut down. It also includes a wireless receiving unit 9, which is connected to the control unit 5 and the power supply unit 7. The wireless receiving unit 9 is wirelessly connected to an external remote controller via infrared rays or radio waves.

[0037] The wireless receiving unit 9 receives an external wireless signal with a light pattern code, and converts the wireless signal into a control signal of the control unit 5 and sends it to the control unit 5. The control unit 5 is set with a plurality of light patterns. According to the selected light pattern, the control unit 5 generates a corresponding light pulse signal according to the light pattern code containing address code and color code information. When there is no light pulse signal to be transmitted, the control unit 5 controls the switch unit 4 to be turned on, and the power unit 7 transmits a DC power supply with a first voltage to the light emitting diode light string 1 to drive the light emitting diode light string 1; when the light pulse signal generated by the control unit 5 is to be transmitted, the control unit 5 controls the opening and closing action of the switch unit 4 according to the light pulse signal. When the control unit 5 controls the switch unit 4 to be turned off, the DC power supply with a second voltage of the second power generation unit 3 is transmitted to the light emitting diode light string 1 to provide a working voltage for the internal chip of the light emitting diode. The control unit 5 controls the opening and closing action of the switch unit 4 to form a plurality of light control commands with a first voltage and a second voltage, and outputs the light control command to the electrically connected light emitting diode light string 1, and the light emitting diode light string 1 receives the light control command and performs a corresponding light emission change. The second voltage is less than the first voltage. The short-circuit protection unit (2) detects the voltage value at the cathode end of the light-emitting diode lamp string (1); when the voltage value is greater than a critical value, the short-circuit protection unit (2) sends a second protection signal, and the control unit (5) controls the switch unit (4) to be turned off, and then controls the switch unit (4) to be turned on after a predetermined time T; when the current voltage is less than the critical value, the short-circuit protection unit (2) sends a first protection signal or does not send a signal.

[0038] like Figure 2As shown, the power supply unit 7 is a +5V DC power supply VDD. The power supply end of the control unit 5 is connected to the DC power supply VDD. The control unit 5 includes a microprocessor and a voltage stabilizing circuit. The input end of the voltage stabilizing circuit is connected to the DC power supply VDD, and the output end is connected to the power supply end of the microprocessor. The voltage stabilizing circuit is used to convert the DC power supply VDD into the working voltage of the microprocessor. The switch unit 4 is a P-channel enhancement type field effect transistor Q1. The gate of the field effect transistor Q1 is connected to the control unit 5, the source is connected to the DC power supply VDD, and the drain is connected to the anode end of the light-emitting diode light string 1. The second power supply generating unit 3 includes a first resistor R1, a second capacitor C2, a diode D1, and a voltage stabilizing element; the first resistor R1 is used for voltage division, the second capacitor C2 is used for filtering, and the voltage stabilizing element is a light-emitting diode LED1, which is used to determine the value of the second voltage. One end of the first resistor R1 is connected to the DC power supply VDD, and the other end is respectively connected to the anode of the diode D1, the anode of the grounded light-emitting diode LED1 and the grounded second capacitor C2, and the cathode of the diode D1 is connected to the anode end of the light-emitting diode light string 1. The short-circuit protection unit 2 includes a third resistor R3, a fourth resistor R4, a transistor Q2 and a second resistor R2, wherein the cathode end of the light-emitting diode lamp string 1 is connected to the grounded third resistor R3 and the fourth resistor R4, and the other end of the fourth resistor R4 is connected to the base of the transistor Q2; the emitter of the transistor Q2 is grounded, and the collector is respectively connected to the control unit 5 and the DC power supply VDD via the second resistor R2, and the second resistor R2 is used to improve the reliability of the signal output of the short-circuit protection unit 2. In other embodiments, since the port connecting the control unit 5 and the short-circuit protection unit 2 is automatically high when there is no signal input, the collector can be directly connected to the control unit 5, and the connection between the second resistor R2 and the DC power supply VDD is omitted; when the transistor Q2 is turned off, the short-circuit protection unit 2 does not output a signal to the control unit 5. The wireless receiving unit 9 includes a voltage stabilizing chip and a wireless receiving chip. The voltage stabilizing chip is connected to a DC power supply VDD and is used to convert the DC power supply VDD into an operating voltage of the wireless receiving chip. The voltage stabilizing chip is connected to a power supply end of the wireless receiving chip. The output end of the wireless receiving chip is connected to the control unit 5. The input end of the wireless receiving chip receives a wireless signal from an external remote control.

[0039] The working principle of the LED light string control system 6 is:

[0040] 1. When the power is turned on, the wireless receiving unit 9 receives the wireless signal with the light pattern code sent by the external remote control, and converts the wireless signal into a control signal of the control unit 5 and sends it to the control unit 5.

[0041] 2. The DC power supply VDD turns on the light-emitting diode LED1 through the first resistor R1; the DC power supply VDD supplies power to the control unit 5. When there is no light pulse signal to be transmitted, the control unit 5 sends a low level to the gate of the field effect tube Q1, so the gate potential of the field effect tube Q1 is low, and the source potential is high. Therefore, the field effect tube Q1 is turned on, and its drain potential is higher than the anode potential of the diode D1. The diode D1 is cut off, and the current flows from the DC power supply VDD through the source and drain of the field effect tube Q1 to the light-emitting diode lamp string 1. The DC power supply with the first voltage supplies power to the light-emitting diode lamp string 1, driving the light-emitting diode lamp string 1 to emit light.

[0042] 3. When the control unit 5 is to send a light pulse signal consisting of a plurality of low levels and high levels, when the control unit 5 sends a high level to the gate of the field effect tube Q1, the gate potential of the field effect tube Q1 is high, the source potential is also high, and the voltage difference between the gate and the source is less than 2V, so the field effect tube Q1 is cut off, and its drain potential is pulled down, and the drain potential is lower than the anode potential of the diode D1, thereby turning on the diode D1, and the current flows from the DC power supply VDD through the first resistor R1 and the diode D1 to the LED light string 1, and the DC power supply with the second voltage supplies power to the LED light string 1; the control unit 5 controls the continuous opening and closing actions of the field effect tube Q1 to form a plurality of light control commands with the first voltage or the second voltage, and outputs the light control command to the electrically connected LED light string 1, and the LED light string 1 receives the light control command and performs corresponding light emission changes.

[0043] 4. When the LED light string 1 works normally, the field effect tube Q1 is turned on, and the current flowing through the third resistor R3 is less than 300MA. The voltage at the cathode end of the LED light string 1 is about 0.225V, and the turn-on voltage V BE of the transistor Q2 is about 0.5V. The voltage difference between the base and the emitter of the transistor Q2 is less than 0.225V, which is smaller than the turn-on voltage of the transistor Q2. Therefore, the transistor Q2 is in the cut-off state, and the current flows from the DC power supply VDD through the second resistor R2 to the control unit 5. The control unit 5 receives the first protection signal of a high level, and the control unit 5 controls the on and off action of the field effect tube Q1 according to the light pulse signal. When a certain LED in the LED light string 1 is short-circuited, the DC power supply VDD is connected to the cathode end of the LED light string 1, i.e., the end of the third resistor R3, through the turned-on field effect transistor Q1. The potential of the third resistor R3 increases, and the voltage value is equivalent to the first voltage. The turn-on voltage V BE of the transistor Q2 is the critical value. When the voltage at the cathode end is greater than the turn-on voltage V When BE, the voltage difference between the base and the emitter of the transistor Q2 is much greater than 0.5V, so the transistor Q2 is turned on, and the DC power supply VDD is grounded through the second resistor R2, the collector and the emitter of the transistor Q2. The control unit 5 receives the second protection signal of a low level. When the control unit 5 receives the low level, it controls the field effect transistor Q1 to be cut off. At this time, the light-emitting diode lamp string 1 does not emit light, and the light-emitting pulse signal of the control unit 5 cannot generate a light-emitting control command to be transmitted to the light-emitting diode through the switch unit 4. The light-emitting diode lamp string control system 6 enters a short-circuit protection state to prevent the light-emitting diode lamp string 1 from being burned out due to long-term access to the higher first voltage, thereby realizing lamp string protection, and the light-emitting diode LED1 in the second power generation unit does not light up, which serves to prompt a short-circuit fault.After receiving the second protection signal of low level, the control unit 5 controls the field effect tube Q1 to be turned off and controls the field effect tube Q1 to be turned on again after a delay of a predetermined time T. If the LED light string 1 is still short-circuited, the transistor Q2 is turned on. After receiving the low level again, the control unit 5 quickly controls the field effect tube Q1 to be turned off. The control unit 5 controls the field effect tube Q1 to be turned on again after a predetermined time T. The above process is repeated until the fault is removed and the transistor Q3 is turned off. Whether the short-circuit fault is removed is monitored in real time. The conduction time of the field effect tube Q1 is very short, which can prevent the LED light string 1 from burning out. When the short-circuit fault is removed, the LED light string 1 works normally, and the DC power supply with the first voltage supplies power to the LED light string 1. The voltage at the cathode end of the LED light string 1 is pulled down, and the current flowing through the third resistor R3 becomes smaller, and its current is less than 300MA. The voltage at the cathode end is less than 0.225V, which is also less than the turn-on voltage V BE of the transistor Q2. Therefore, the voltage difference between the base and the emitter of the transistor Q2 is less than the turn-on voltage of the transistor Q2, and the transistor Q2 is turned off. The current flows from the DC power supply VDD to the control unit 5 through the second resistor R2. After the control unit 5 receives the high-level first protection signal, the control unit 5 controls the on and off actions of the field effect transistor Q1 according to the light pulse signal, and the light-emitting diode light string control system 6 automatically resumes normal operation.

[0044] The present invention loads the light control command sent by the control unit 5 to the power line of the LED light string 1 in a carrier manner to drive the lighting changes of the LED light string 1, so that a plurality of parallel LEDs can operate synchronously or asynchronously without the need for additional signal transmission lines, thereby saving costs and simplifying the control circuit of the LED light string 1.

[0045] The short-circuit protection unit 2 of the present invention detects in real time whether the light-emitting diode is short-circuited, and has a fast protection response speed when the light-emitting diode light string 1 is short-circuited. Once a short-circuit fault is detected, the short-circuit protection unit 2 sends a low-level second protection signal to the control unit 5, and the control unit 5 controls the switch unit 4 to be cut off, and the light-emitting diode light string 1 is disconnected from the DC power supply with the first voltage in time, protecting the remaining light-emitting diodes and the power supply unit 7, thereby reducing maintenance costs and economic losses; when the short-circuit fault is removed, the light-emitting diode light string control system 3 can automatically resume normal operation, reduce maintenance work, and improve resource utilization. The short-circuit protection unit 2 only needs one transistor and two resistors to be implemented, the circuit is simple, the required components are few, and it is easy to implement. The present invention can be remotely controlled, and the brightness, color and luminous changes of the light-emitting diode light string 1 can be freely adjusted.

[0046] The above description is an explanation of the present invention, not a limitation of the present invention. The present invention may be modified in any form without violating the spirit of the present invention.

Claims

1. A light emitting diode light string control system, Features include: The switch unit (4) has a power input terminal (41), a power output terminal (42) and a controlled terminal (43), wherein the power output terminal (42) is connected to the light emitting diode lamp string (1); A control unit (5), the control unit (5) being connected to a controlled end (43) of the switch unit (4); A second power generation unit (3), the second power generation unit (3) being connected to the light emitting diode light string (1); It also includes a short circuit protection unit (2), which includes: A third resistor R3, the third resistor R3 is connected to the cathode end of the light emitting diode light string (1); A fourth resistor R4, the fourth resistor R4 is connected to the base of the transistor Q2 and the third resistor R3; A transistor Q2, wherein the collector of the transistor Q2 is connected to a control unit (5); When no light pulse signal is to be transmitted, the control unit (5) controls the switch unit (4) to be turned on, and the power supply unit (7) transmits a direct current power with a first voltage to the light emitting diode light string (1) to drive the light emitting diode light string (1) to emit light; when a light pulse signal generated by the control unit (5) is to be transmitted, the control unit (5) controls the on / off action of the switch unit (4); when the control unit (5) controls the switch unit (4) to be turned off, direct current with a second voltage from the second power supply generating unit (3) is transmitted to the light emitting diode light string (1); the second voltage is lower than the first voltage.

2. The light emitting diode light string control system according to claim 1, Features: It also comprises a short circuit protection unit (2), the short circuit protection unit (2) being connected to the control unit (5) and the light emitting diode light string (1); the short circuit protection unit (2) detecting the voltage value at the cathode end of the light emitting diode light string (1); when the voltage value is greater than a critical value, the short circuit protection unit (2) sends a second protection signal, and the control unit (5) controls the switch unit (4) to be cut off; when the current voltage is less than the critical value, the short circuit protection unit (2) sends the first protection signal or does not send a signal.

3. The light emitting diode light string control system according to claim 1, Features: The short-circuit protection unit (2) further comprises a second resistor R2, and two ends of the second resistor R2 are respectively connected to the collector of the transistor Q2 and the power supply unit (7).

4. The light emitting diode light string control system according to claim 1, Features: The second power generation unit (3) comprises: A first resistor R1, the first resistor R1 is connected to a power supply unit (7); Capacitor C2, capacitor C2 is connected to the first resistor R1; A diode D1, the diode D1 is connected to the first resistor R1 and the power output terminal (42); A voltage stabilizing element is connected to the first resistor R1.

5. The light emitting diode light string control system according to claim 4, Features: The voltage stabilizing element is a light emitting diode LED1.

6. The light emitting diode light string control system according to claim 1, Features: It also includes a wireless receiving unit (9), the wireless receiving unit (9) is connected to the control unit (5) and the power supply unit (7), and the wireless receiving unit (9) is connected to an external remote controller via radio waves or infrared rays.

7. The light emitting diode light string control system according to claim 1, Features: It also includes a storage unit (8), which is connected to the control unit (5) and stores the address code and color code of the light emitting diode light string (1).

8. The light emitting diode light string control system according to claim 1, Features: The switch unit (4) is a field effect tube, and the control unit (5) includes a microprocessor.

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