Parallel sequenced LED string

Abstract

The present invention provides a parallel sequenced LED light string comprising a plurality of LED modules. Each of the LED modules is connected in parallel via a power line having a plurality of line resistors. Each of the LED modules comprises an impedance element that can provide impedance characteristics. Each of the LED modules connected in parallel receives a power supply, and the power supply passes through each of the line resistors and each of the impedance elements, so that the voltages generated on each of the LED modules are different, and each of the LED modules is sequenced.

Description

Technical Field

[0001] The present invention relates to a light emitting diode light string, and more particularly to a parallel sequenced light emitting diode light string with impedance compensation technology. Background Art

[0002] Since light-emitting diodes (LEDs) have the advantages of high luminous efficiency, low power consumption, long life, fast response speed, high reliability, etc., LEDs have been widely used in lighting fixtures or decorative lighting in the form of series, parallel or series-parallel connection of light bars or light strings, such as Christmas tree lights, sports shoe lighting effects, etc.

[0003] Taking festival lighting as an example, a complete LED lamp basically includes an LED light string (with a number of lamps) and a driving unit for driving the lamps. The driving unit is electrically connected to the light string, and by providing the lamps with the required power and a control signal with light-emitting data, the lamps are controlled in a point-controlled or synchronous manner to achieve a variety of light output effects and changes of the LED lamps.

[0004] According to the existing technology, in order to drive each LED of the LED light string to emit light in a diversified manner, each LED has different address sequence data. Each LED receives a light signal including light emission data and address data: if the address sequence data of the LED is the same as the address data of the light emission signal, the LED emits light according to the light emission data of the light emission signal; if the address sequence data of the LED is different from the address data of the light emission signal, the LED skips the light emission data of the light emission signal.

[0005] Currently, the sequencing methods of the LEDs of the LED light string are mostly complicated or difficult; for example, before the LEDs are combined into the LED light string, different address sequence data need to be burned into each LED. Afterwards, the LEDs are placed in sequence according to the address sequence data and combined into the LED light string. If the LEDs are not placed in sequence according to the address sequence data, the diversified light emission of the LEDs cannot be achieved correctly. Summary of the invention

[0006] The object of the present invention is to provide a parallel sequenced LED light string with impedance compensation technology to solve the problems existing in the prior art of using addresses as LED sequencing.

[0007] To achieve the above-mentioned purpose, the parallel sequenced LED light string proposed in the present invention comprises a plurality of LED modules. Each of the LED modules is connected in parallel via a power line having a plurality of line resistors. Each LED module comprises an impedance element that can provide impedance characteristics. Each of the LED modules connected in parallel receives a power supply, and the power supply passes through each of the line resistors and each of the impedance elements, so that the voltages generated on each of the LED modules are different, and each of the LED modules is sequenced.

[0008] In one embodiment, the magnitude of each of the generated voltages is compared with a plurality of voltage ranges to determine the sequence of each of the light emitting diode modules.

[0009] In one embodiment, each of the voltage ranges is established in a lookup table.

[0010] In one embodiment, each of the voltage ranges is determined according to the size of the power supply, the number of each of the light emitting diode modules, the size of each of the line resistances, and the size of each of the impedance elements.

[0011] In one embodiment, the power supply is a constant voltage source, each of the impedance elements is a controllable resistor with an adjustable resistance value, and the resistance value of the controllable resistor is designed to be reduced.

[0012] In one embodiment, the voltage generated by the front LED module is greater than the voltage generated by the rear LED module.

[0013] In one embodiment, the power supply is a constant current source, each of the impedance elements is a controllable resistor with an adjustable resistance value, and the resistance value of the controllable resistor is designed to be increased.

[0014] In one embodiment, the voltage generated by the front LED module is smaller than the voltage generated by the rear LED module.

[0015] In one embodiment, the parallel sequenced LED light string further comprises a signal generating unit. The signal generating unit provides a sequence signal; each of the impedance elements is a controllable resistor with an adjustable resistance value.

[0016] In one embodiment, the order of each of the light-emitting diode modules is determined according to the periodic order of the sequence signal; the power supply is a constant voltage source, and when the sequencing of a light-emitting diode module is completed, the corresponding impedance element is turned off, and the resistance value of the impedance element corresponding to the unsequenced light-emitting diode module is reduced.

[0017] In one embodiment, the order of each of the light-emitting diode modules is determined according to the periodic order of the sequence signal; the power supply is a constant current source, and when the sequencing of one light-emitting diode module is completed, the corresponding impedance element is turned off, and the resistance value of the impedance element corresponding to the unsequenced light-emitting diode module is increased.

[0018] In one embodiment, the parallel sequenced LED light string further comprises a switch unit. The switch unit is connected in series with the controllable resistor.

[0019] In one embodiment, each of the light emitting diode modules comprises a plurality of resistors and a plurality of switch units, and each of the switch units is correspondingly connected in series with each of the plurality of resistors.

[0020] In one embodiment, the parallel-sequenced LED light string further comprises a compensation unit. The compensation unit is coupled in parallel to the last LED module. The compensation unit comprises a controllable resistor with adjustable resistance value.

[0021] In one embodiment, the power supply is a constant voltage source; when the light emitting diode modules are sequenced sequentially, the resistance of the controllable resistor decreases sequentially.

[0022] In one embodiment, the power supply is a constant current source; when the light emitting diode modules are sequenced sequentially, the resistance of the controllable resistor increases sequentially.

[0023] The proposed parallel sequenced LED light string provides a corresponding search for the detected voltage through the voltage range information provided by the built-in lookup table, and determines the light sequence of the LED module based on the difference in voltage magnitude, thereby simplifying the circuit design and quickly completing the sequencing of the LED light string. In addition, by using a controllable resistor with adjustable resistance or a parallel design of several resistors or adjusting the resistance of a compensation unit, the accuracy of comparison, judgment, and identification between the detected voltage and the voltage range of the lookup table can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1A : Circuit diagram of a first embodiment of a parallel sequenced LED light string powered by a constant voltage source of the present invention.

[0025] Figure 1B : Circuit diagram of a first embodiment of a parallel sequenced LED light string powered by a constant current source of the present invention.

[0026] Figure 2A : Circuit diagram of a second embodiment of a parallel sequenced LED light string powered by a constant voltage source of the present invention.

[0027] Figure 2B: Circuit diagram of a second embodiment of a parallel sequenced LED light string powered by a constant current source of the present invention.

[0028] Figure 3A : is a voltage schematic diagram of the first embodiment of the parallel sequenced LED light string of the present invention.

[0029] Figure 3B : is a voltage schematic diagram of the second embodiment of the parallel sequenced LED light string of the present invention.

[0030] Figure 4 : is a circuit block diagram of a controllable resistor implementation method of the present invention.

[0031] Figure 5 : is a circuit block diagram of a multi-resistance implementation method of the present invention.

[0032] Figure 6 : is a circuit block diagram of the counting operation of the present invention.

[0033] In the figure:

[0034] 10: power line; 11, 12, ..., 1N: light emitting diode module;

[0035] R L1 ,R L2 ,…,R LN ,R L1’ ,R L2’ ,…,R LN’ : Line resistance; R 1 ,R 2 ,…,R N :resistance;

[0036] C 1 ,C 2 ,…,C N : Parasitic capacitance; V 1 ,V 2 ,…,V N :Voltage;

[0037] Vdc: power supply; Idc: power supply; R11, R21, R22: resistors; Q11, Q21, Q22: switch units;

[0038] 31: voltage stabilizing unit; 32: analog-to-digital conversion unit. DETAILED DESCRIPTION

[0039] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0040] See also Figure 1A As shown in FIG. 1 , it is a circuit diagram of a first embodiment of a parallel sequenced LED light string powered by a constant voltage source of the present invention. The parallel sequenced LED light string comprises a plurality (N) of LED modules 11, 12, ..., 1N. Each of the LED modules 11, 12, ..., 1N is connected in parallel via a power line 10. For an actual circuit, the power line 10 has a line resistance, so the power line 10 has a plurality of line resistances R L1 ,R L2 ,…,R LN ,R L1’ ,R L2’ ,…,R LN’ Each of the light emitting diode modules 11, 12, ..., 1N comprises a resistor R 1 ,R 2 ,…,R N , and can be equivalent to the corresponding resistance R 1 ,R 2 ,…,R N Parallel parasitic capacitance C 1 ,C 2 ,…,C N , that is, the first light emitting diode module 11 includes a first resistor R 1 The first parasitic capacitor C in parallel 1 The second light emitting diode module 12 includes a second resistor R 2 The second parasitic capacitor C in parallel 2 , ... the Nth light emitting diode module 1N includes the Nth resistor R N The Nth parasitic capacitor C in parallel N .

[0041] like Figure 1A As shown, each of the LED modules 11, 12, ..., 1N connected in parallel receives a power supply Vdc. In this embodiment, the power supply Vdc is a constant voltage source, which is used to provide a voltage source with a fixed voltage. The power supply Vdc is connected to the resistor R L1 ,R L2 ,…,R LN ,R L1’ ,R L2’ ,…,R LN’ and each of the resistors R in each of the light emitting diode modules 11, 12, ..., 1N 1 ,R 2 ,…,R N , so that the voltages generated on the light emitting diode modules 11, 12, ..., 1N are different in magnitude.

[0042] When powered on, since the circuits in the LED modules 11, 12, ..., 1N have not yet started and operated, the LED modules 11, 12, ..., 1N can be equivalent to corresponding resistors R 1 ,R 2 ,…,R N Furthermore, for the convenience of explanation, the line resistance R L1 With line resistance R L1’ Equivalent to a single line resistance R L1 Similarly, the line resistance R L2 With line resistance R L2’ Equivalent to a single line resistance R L2 ,…Line resistance R LN With line resistance R LN’ Equivalent to a single line resistance R LN .

[0043] When powered on, the power supply Vdc supplies power to each of the light emitting diode modules 11, 12, ..., 1N. As the current flows through each line resistor R L1 ,R L2 ,…,R LN The voltage difference caused by the constant voltage source Vdc is passed through each line resistor R L1 ,R L2 ,…,R LN The voltage difference caused is a voltage drop, so the voltages generated on the light emitting diode modules 11, 12, ..., 1N are different in magnitude. Figure 3A As shown, it is a voltage schematic diagram of the first embodiment of the parallel sequenced LED light string of the present invention, a first voltage V on the first LED module 11 1 is greater than a second voltage V on the second LED module 12 2 , the second voltage V 2 is greater than a third voltage V on the third LED module 13 3 , ... and so on, that is, the voltage generated by the front (upstream) LED module is greater than the voltage generated by the rear (downstream) LED module (V 1 >V 2 >…>V N ). Thus, according to the generated voltage V 1 ,V 2 ,…,V N The sizes of the LED modules 11, 12, ..., 1N are sequenced. 1 ,V 2 ,…,V N The sequencing principle of the light emitting diode modules 11, 12, ..., 1N with different sizes is explained.

[0044] In one embodiment, this can be achieved by building a corresponding lookup table. For example, the circuit designer can calculate the power supply Vdc, the number of each of the LED modules 11, 12, ..., 1N, and the line resistance R L1 ,R L2 ,…,R LN The (estimated) size of each resistor R 1 ,R 2 ,…,R N The size of the lookup table is pre-established to generate the voltage V 1 ,V 2 ,…,V N , so as to achieve the sequencing of each of the light emitting diode modules 11, 12, ..., 1N.

[0045] As shown below, an implementation of the lookup table is shown, wherein 100 light emitting diode modules 11, 12, ..., 1N are taken as an example for explanation.

[0046] Light sequence Voltage Range (Volts) #1 5.10~4.90 #2 4.90~4.70 #3 4.70~4.54 #4 4.54~4.38 #5 4.38~4.26 #6 4.26~4.14 … … #100 2.36~2.32

[0047] When the LED light string is powered on, the power supply Vdc supplies power to each of the LED modules 11, 12, ..., 1N, thereby generating a first voltage V on the first LED module 11. 1 , a second voltage V is generated on the second LED module 12 2 , ...will generate the Nth voltage V on the Nth light emitting diode module 1N N For example, when a voltage (eg, a first voltage V 1 ) is 5.00 volts, since the voltage is within the voltage range (5.10-4.90 volts) of the first light sequence (#1), the LED module can be sequenced as the first LED module 11. Similarly, when the voltage (e.g., the second voltage V 2 ) is 4.80 volts, since the voltage is within the voltage range (4.90-4.70 volts) of the second light sequence (#2), the LED module can be sequenced as the second LED module 12. Similarly, when the voltage (e.g., the sixth voltage V 6) is 4.20 volts, since the voltage is within the voltage range (4.26-4.14 volts) of the sixth light sequence (#6), the LED module can be sequenced as the sixth LED module 16.

[0048] Thus, after the LED light string is powered on, the voltage V generated by each of the LED modules 11, 12, ..., 1N can be detected. 1 ,V 2 ,…,V N , the corresponding voltage range of the built-in lookup table can obtain the light sequence of each of the light-emitting diode modules 11, 12, ..., 1N. The above voltage range is not limited to the voltage value given as an example, and can be adjusted according to the size of the power supply Vdc, the number of each of the light-emitting diode modules 11, 12, ..., 1N, and the line resistance R L1 ,R L2 ,…,R LN The (estimated) size of each resistor R 1 ,R 2 ,…,R N The size, or other parameters, of the voltage range of the pre-established lookup table that can achieve the corresponding detection voltage should all be included in the scope of the present invention.

[0049] See also Figure 1B , which is a circuit diagram of the first embodiment of the parallel sequenced LED light string powered by a constant current source of the present invention. In addition to realizing the power supply Vdc in the form of a constant voltage source, the present invention can also be realized in the form of a constant current source, that is, in this embodiment, the power supply Idc is a constant current source, which is used to provide a current source with a fixed current size. The power supply Idc is connected to the line resistor R L1 ,R L2 ,…,R LN ,R L1’ ,R L2’ ,…,R LN’ and each of the resistors R in each of the light emitting diode modules 11, 12, ..., 1N 1 ,R 2 ,…,R N , so that the voltages generated on the light emitting diode modules 11, 12, ..., 1N are different in magnitude.

[0050] When powered on, since the circuits in the LED modules 11, 12, ..., 1N have not yet started and operated, the LED modules 11, 12, ..., 1N can be equivalent to corresponding resistors R 1 ,R 2 ,…,RN Furthermore, for the convenience of explanation, the line resistance R L1 With line resistance R L1’ Equivalent to a single line resistance R L1 Similarly, the line resistance R L2 With line resistance R L2’ Equivalent to a single line resistance R L2 ,…Line resistance R LN With line resistance R LN’ Equivalent to a single line resistance R LN .

[0051] When powered on, the power supply Idc supplies power to each of the light emitting diode modules 11, 12, ..., 1N. Since the current flows through each line resistor R L1 ,R L2 ,…,R LN The voltage difference caused by the constant current source Idc is L1 ,R L2 ,…,R LN The resulting voltage difference is a voltage rise, so the voltages generated on the light emitting diode modules 11, 12, ..., 1N are different in magnitude. Figure 3B As shown, it is a voltage schematic diagram of the second embodiment of the parallel sequenced LED light string of the present invention, a first voltage V 1 is less than a second voltage V on the second LED module 12 2 , the second voltage V 2 is less than a third voltage V on the third LED module 13 3 , ... and so on, that is, the voltage generated by the front (upstream) LED module is smaller than the voltage generated by the rear (downstream) LED module (V 1 <V 2 <… <V N ). Thus, according to the generated voltage V 1 ,V 2 ,…,V N The sizes of the LED modules 11, 12, ..., 1N are sequenced. 1 ,V 2 ,…,V N The sequencing principle of the light emitting diode modules 11, 12, ..., 1N with different sizes is explained.

[0052] In one embodiment, this can be achieved by building a corresponding lookup table. For example, the circuit designer can calculate the power supply Idc based on the size of the power supply Idc, the number of the light emitting diode modules 11, 12, ..., 1N, and the line resistance R L1 ,R L2 ,…,R LN The (estimated) size of each resistor R 1 ,R 2 ,…,R N The size of the lookup table is pre-established to generate the voltage V 1 ,V 2 ,…,V N , so as to achieve the sequencing of each of the light emitting diode modules 11, 12, ..., 1N.

[0053] As shown below, an implementation of the lookup table is shown, wherein 100 light emitting diode modules 11, 12, ..., 1N are taken as an example for explanation.

[0054] Light sequence Voltage Range (Volts) #1 2.36~2.32 #2 2.40~2.36 #3 2.46~2.40 #4 2.52~2.46 #5 2.60~2.52 #6 2.68~2.60 … … #100 5.10~4.90

[0055] When the LED light string is powered on, the power supply Idc supplies power to each of the LED modules 11, 12, ..., 1N, thereby generating a first voltage V on the first LED module 11. 1 , a second voltage V is generated on the second LED module 12 2 , ...will generate the Nth voltage V on the Nth light emitting diode module 1N N For example, when a voltage (eg, a first voltage V 1 ) is 2.34 volts, since the voltage is within the voltage range (2.36-2.32 volts) of the first light sequence (#1), the LED module can be sequenced as the first LED module 11. Similarly, when the voltage (e.g., the second voltage V 2 ) is 2.38 volts, since the voltage is within the voltage range (2.40-2.36 volts) of the second light sequence (#2), the LED module can be sequenced as the second LED module 12. Similarly, when the voltage (e.g., the sixth voltage V 6 ) is 2.64 volts, since the voltage is within the voltage range (2.68-2.60 volts) of the sixth light sequence (#6), the LED module can be sequenced as the sixth LED module 16.

[0056] Thus, after the LED light string is powered on, the voltage V generated by each of the LED modules 11, 12, ..., 1N can be detected. 1 ,V 2 ,…,V N , the corresponding voltage range of the built-in lookup table can obtain the light sequence of each of the light-emitting diode modules 11, 12, ..., 1N. The above voltage range is not limited to the voltage value given as an example, and can be adjusted according to the size of the power supply Idc, the number of each of the light-emitting diode modules 11, 12, ..., 1N, and the line resistance R L1 ,R L2 ,…,R LN The (estimated) size of each resistor R 1 ,R 2 ,…,R N The size, or other parameters, of the voltage range of the pre-established lookup table that can achieve the corresponding detection voltage should all be included in the scope of the present invention.

[0057] by Figure 1A In the first embodiment shown (i.e., the constant voltage source power supply mode), in order to improve the accuracy of the comparison, judgment, and identification of the detected voltage and the voltage range of the lookup table, therefore, each of the resistors R in each of the light-emitting diode modules 11, 12, ..., 1N 1 ,R 2 ,…,R N It can be a controllable resistor with adjustable resistance. And, when the LED modules 11, 12, ..., 1N are sequenced at power-on, each controllable resistor (ie, each resistor R 1 ,R 2 ,…,R N ) is designed to be the minimum value so that the current flowing through each resistor R 1 ,R 2 ,…,R N The current is the largest, so the voltage V generated on each of the light emitting diode modules 11, 12, ..., 1N is 1 ,V 2 ,…,V N It can be the maximum, thereby improving the accuracy of comparison, judgment, and identification of the detected voltage and the voltage range of the lookup table.

[0058] Furthermore, in circuit applications, due to the power supply Vdc that provides a constant voltage source and the equivalent resistance effect, the current at the back is smaller, resulting in a smaller voltage difference between the back LED modules. Figure 3A As shown, for example, a first voltage V generated on the first light emitting diode module 1and the second voltage V generated on the second light emitting diode module 2 The voltage difference will be greater than the second voltage V 2 and the third voltage V generated on the third light emitting diode module 3 The voltage difference (i.e., V 3 -V 2 <V 2 -V 1 ), and the voltage difference between the two LED modules at the back will be smaller. Figure 1B and Figure 3B As shown, for the power supply Idc providing a constant current source, its circuit effect is similar to that of the power supply Vdc providing a constant voltage source, but the effect is opposite. Therefore, the operating principle of the power supply Vdc providing a constant voltage source hereinafter is also applicable to the power supply Idc providing a constant current source, and will not be described in detail. Only the operating principle of the power supply Vdc providing a constant voltage source is described as follows.

[0059] Therefore, in order to avoid the decrease in the accuracy of comparison, judgment and identification of the detected voltage and the voltage range of the lookup table due to the smaller voltage difference between the LED modules at the rear, the LED light string of the present invention is arranged in parallel and sequenced by adjusting each of the resistors R 1 ,R 2 ,…,R N The resistance value is adjusted to maintain the current consistency, so that the voltage difference between any two light-emitting diode modules remains constant, so as to improve the accuracy of the comparison, judgment and identification of the detected voltage and the voltage range of the lookup table. 1 ,R 2 ,…,R N The specific description is as follows.

[0060] The sequence signal is a pulse signal, that is, a signal with alternating high and low levels, and each high level (or low level) can be used as a basis for the sequence. That is, the first cycle can be regarded as the first sequence, the second cycle can be regarded as the second sequence, and so on.

[0061] Therefore, when the power is first turned on, because each resistor R 1 ,R 2 ,…,R N The first voltage V corresponding to the first order (first cycle) of the pulse signal can be obtained. 1 size.

[0062] When the first power-on is completed, the first resistor R1 Close, for example, the first resistor R 1 The resistance value is adjusted to a relatively large value, which is like an open circuit for the current, so that the current flowing through the first resistor R 1 The current approaches zero, or by connecting the first resistor R in series 1 The switch element is turned off, so that the current flowing through the first resistor R 1 The current is zero, and the second resistor R 2 The resistance of the last LED module (e.g., the 100th resistor), that is, the resistance of the remaining 99 resistors, is reduced, for example but not limited to 1 / 100 of the original resistance. Therefore, since the resistance of the remaining resistors is reduced, the equivalent resistance value after parallel connection will be the same, so that the current flowing through can be the same. When the power is turned on again, the second voltage V corresponding to the second order (second cycle) of the pulse signal can be obtained. 2 size.

[0063] Similarly, when the second power-on is completed, the first resistor R 1 With the second resistor R 2 are all closed, for example, the first resistor R 1 With the second resistor R 2 The resistance value is adjusted to a relatively large value, which is like an open circuit for the current, so that the current flowing through the first resistor R 1 With the second resistor R 2 The current approaches zero, and the third resistor R of the third LED module 12 is 3 The resistance of the last LED module (e.g., the 100th resistor), that is, the resistance of the remaining 98 resistors, is reduced, for example but not limited to 1 / 100 of the previous resistance. Therefore, since the resistance of the remaining resistors is reduced, the equivalent resistance value after parallel connection will be the same, so that the current flowing through can be the same. When the power is turned on again, the third voltage V corresponding to the third order (third cycle) of the pulse signal can be obtained. 3 Thus, the sequence signal can be used as the basis of the sequence, and the resistance value of the remaining resistor can be adjusted (reduced) to maintain the current consistent, so that the voltage difference between any two light-emitting diode modules remains fixed, so as to improve the accuracy of comparison, judgment, and identification of the detected voltage and the voltage range of the lookup table.

[0064] Compared to Figure 1A Constant voltage power supply, Figure 1BThe impedance compensation of the constant current power supply is achieved by increasing the resistance of the remaining resistors so that the equivalent resistance after parallel connection will increase, which can reduce the current flowing through. In this way, the sequence signal can be used as the basis of the sequence, and the resistance of the remaining resistors can be adjusted (increased) to maintain the current consistency, so that the voltage difference between any two light-emitting diode modules remains fixed, so as to improve the accuracy of the comparison, judgment, and identification of the detected voltage and the voltage range of the lookup table.

[0065] See also Figure 2A and Figure 2B As shown, they are respectively the circuit diagram of the second embodiment of the parallel sequenced LED light string powered by the constant voltage source of the present invention and the circuit diagram of the second embodiment of the parallel sequenced LED light string powered by the constant current source of the present invention. Figure 2A and Figure 3A For example, and can be applied to Figure 2B The power supply Idc that provides a constant current source will not be described in detail, and only the operating principle of the power supply Vdc that provides a constant voltage source will be described as follows.

[0066] Figure 2A The LED light string shown is Figure 1A The biggest differences between the LED light strings shown are: Figure 2A The resistance value of each LED module 11, 12, ..., 1N in the LED light string does not have the same Figure 1A is a controllable characteristic, that is, to achieve the effect of resistance compensation, Figure 2A The LED light string shown in the figure further comprises a compensation unit 20, which is used to replace the Figure 1A The resistance value of each light emitting diode module 11, 12, ..., 1N can be controlled and adjusted. In other words, Figure 1A and Figure 1B The implemented compensation method with adjustable resistance (i.e. controllable resistance) is realized by the compensation unit 20, thus not only simplifying the circuit control but also saving the circuit cost. The compensation unit 20 is an integrated circuit (IC) having a counting function, or the compensation unit 20 is a circuit composed of a ratio circuit and a digital circuit having a counting function.

[0067] When the power is first turned on, the resistor R 1 ,R 2 ,…,R N The first voltage V corresponding to the first order (first cycle) of the pulse signal can be obtained. 1 size.

[0068] When the first power-on is completed, the first resistor R 1 The second voltage V corresponding to the second sequence (second cycle) of the pulse signal can be obtained when the power is turned on again. 2 size.

[0069] Similarly, when the second power-on is completed, the first resistor R 1 With the second resistor R 2 are all closed, and the impedance of the compensation unit 20 is controlled to be reduced so that the equivalent resistance value after parallel connection is the same, that is, the first resistor R 1 With the second resistor R 2 When both are turned off, the impedance of the compensation unit 20 is smaller than that of only the first resistor R 1 The impedance when turned off (i.e., the impedance compensation of the compensation unit 20) can make the current flowing through the same. When the power is turned on again, the third voltage V corresponding to the third order (third cycle) of the pulse signal can be obtained. 3 Thus, the sequence signal can be used as the basis of the sequence, and the impedance of the compensation unit 20 can be adjusted (reduced) to maintain the current consistency, so that the voltage difference between any two light-emitting diode modules is kept constant, so as to improve the accuracy of the detected voltage recognition.

[0070] Compared to Figure 2A Constant voltage power supply, Figure 2B The impedance compensation of the constant current power supply is achieved by increasing the resistance of the compensation unit 20 so that the equivalent resistance value after parallel connection will increase, which can reduce the current flowing through. In this way, the sequence signal can be used as the basis of the sequence, and the resistance of the compensation unit 20 can be adjusted (increased) to maintain the current consistency, so that the voltage difference between any two light-emitting diode modules remains fixed, thereby improving the accuracy of the detected voltage recognition.

[0071] See also Figure 4 As shown, it is a circuit block diagram of the controllable resistor implementation method of the present invention. As mentioned above, the resistor R of each of the light emitting diode modules 11, 12, ..., 1N 1 ,R 2 ,…,R NIt can be a controllable resistor R11 with adjustable resistance. Furthermore, the controllable resistor R11 is connected in series with a switch unit Q11, such as but not limited to a transistor switch. Thus, by adjusting the resistance of the controllable resistor R11 to a reduced value, especially when it is designed to be the minimum value, the current flowing through each of the control resistors R11 will be maximized, so that the voltage V generated on each of the light emitting diode modules 11, 12, ..., 1N is 1 ,V 2 ,…,V N It can be the maximum, thereby improving the accuracy of comparison, judgment, and identification of the detected voltage with the voltage range of the lookup table. Alternatively, the resistance of the controllable resistor R11 can be adjusted to a relatively large value, or the switch unit Q11 can be turned off so that the current flowing through the controllable resistor R11 approaches zero or is equal to zero, thereby maintaining the current consistency and maintaining the voltage difference between any two light-emitting diode modules fixed, so as to improve the accuracy of comparison, judgment, and identification of the detected voltage with the voltage range of the lookup table.

[0072] See also Figure 5 As shown, it is a circuit block diagram of a multi-resistance implementation method of the present invention. Figure 4 The controllable resistor with adjustable resistance shown in the figure can also achieve different resistance designs by connecting multiple resistors in parallel (such as the two resistors R21 and R22 shown in the figure). Each of the resistors R21 and R22 corresponds to a switch unit Q21 and Q22 connected in series, that is, the resistor R21 is connected in series with the switch unit Q21, and the resistor R22 is connected in series with the switch unit Q22. Taking the two resistors R21 and R22 and the two switch units Q21 and Q22 as an example, if a smaller resistance value is to be generated, the switch units Q21 and Q22 can be turned on so that the resistors R21 and R22 are connected in parallel. If a larger resistance value is to be generated, at least one switch unit Q21 and Q22 can be turned off, or even both switch units Q21 and Q22 can be turned off at the same time, so that the equivalent state is an open circuit. By this, the aforementioned improvement in the accuracy of comparison, judgment, and identification of the detected voltage and the voltage range of the lookup table and the maintenance of current consistency can also be achieved, so that the voltage difference between any two light-emitting diode modules is maintained constant to improve the accuracy of comparison, judgment, and identification of the detected voltage and the voltage range of the lookup table. In addition, it also includes a voltage stabilizing unit 31 and an analog-to-digital conversion unit 32. The voltage stabilizing unit 31 is coupled in parallel to each of the resistors R21, R22 and each of the switch units Q21, Q22 to provide a voltage stabilizing operation. The analog-to-digital conversion unit 32 is coupled to the voltage stabilizing unit 31 to provide an operation of converting an analog signal into a digital signal.

[0073] See also Figure 6As shown, it is a circuit block diagram of the counting operation of the present invention, and is also a block diagram of the compensation unit, which is used to implement a compensation method with adjustable resistance (ie, controllable resistance).

[0074] In summary, the present invention has the following features and advantages:

[0075] 1. The voltage range information provided by the built-in lookup table provides the corresponding search for the detected voltage, and the light sequence of the LED module is determined according to the difference in voltage, thereby simplifying the circuit design and quickly completing the sequencing of the LED light string.

[0076] 2. By using a controllable resistor with adjustable resistance or a parallel design of several resistors or adjusting the resistance of the compensation unit 20, the accuracy of comparison, judgment and identification of the detected voltage and the voltage range of the lookup table can be improved.

[0077] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A parallel sequenced LED string, It is characterized in that Include: A plurality of light emitting diode modules are connected in parallel via a power line having a plurality of line resistances, each of the light emitting diode modules comprising an impedance element capable of providing impedance characteristics; Among them, each of the light-emitting diode modules connected in parallel receives a power supply, and the power supply passes through each of the line resistors and each of the impedance elements, so that the voltage generated on each of the light-emitting diode modules is different, and the voltage range information provided by the built-in lookup table corresponds to the different voltage sizes generated to sequence each of the light-emitting diode modules.

2. The parallel sequenced LED light string as claimed in claim 1, It is characterized in that The generated voltage magnitudes are compared with several voltage ranges in the voltage range information of the built-in lookup table to determine the order of each light-emitting diode module, wherein each voltage range is determined according to the magnitude of the power supply, the number of each light-emitting diode module, the magnitude of each line resistance, and the magnitude of each impedance element.

3. The parallel sequenced LED light string as claimed in claim 2, It is characterized in that Each of the voltage ranges is established in a lookup table.

4. The parallel sequenced LED light string as claimed in claim 1, It is characterized in that The power supply is a certain voltage source; Each of the impedance elements is a controllable resistor with an adjustable resistance value, and the resistance value of the controllable resistor is designed to be reduced.

5. The parallel sequenced LED light string as claimed in claim 4, It is characterized in that The voltage generated by the front light emitting diode module is greater than the voltage generated by the rear light emitting diode module.

6. The parallel sequenced LED light string as claimed in claim 1, It is characterized in that The power supply is a constant current source; Each of the impedance elements is a controllable resistor with an adjustable resistance value, and the resistance value of the controllable resistor is designed to be increased.

7. The parallel sequenced LED light string as claimed in claim 6, It is characterized in that The voltage generated by the front light emitting diode module is smaller than the voltage generated by the rear light emitting diode module.

8. The parallel sequenced LED light string as claimed in claim 1, It is characterized in that Also includes: A signal generating unit, providing a sequence signal; Wherein, each of the impedance elements is a controllable resistor with adjustable resistance.

9. The parallel sequenced LED light string as claimed in claim 8, It is characterized in that The order of each light-emitting diode module is determined according to the periodic order of the sequence signal; the power supply is a certain voltage source, and when the sequencing of a light-emitting diode module is completed, the corresponding impedance element is turned off, and the resistance value of the impedance element corresponding to the unsequenced light-emitting diode module is reduced.

10. The parallel sequenced LED light string as claimed in claim 8, It is characterized in that The order of each of the light-emitting diode modules is determined according to the periodic order of the sequence signal; the power supply is a certain current source, and when the sequencing of a light-emitting diode module is completed, the corresponding impedance element is turned off, and the resistance value of the impedance element corresponding to the unsequenced light-emitting diode module is increased.

11. The parallel sequenced LED light string of claim 8, It is characterized in that Also includes: A switch unit is connected in series with the controllable resistor.

12. The parallel sequenced LED string of claim 1, It is characterized in that Each of the light emitting diode modules comprises: certain resistors; and A plurality of switch units are connected in series with the plurality of resistors accordingly.

13. The parallel sequenced LED light string of claim 1, It is characterized in that Also includes: a compensation unit coupled in parallel to the last light emitting diode module; Wherein, the compensation unit includes a controllable resistor with adjustable resistance.

14. The parallel sequenced LED string of claim 13, It is characterized in that The power supply is a certain voltage source; When the light emitting diode modules are sequenced sequentially, the resistance of the controllable resistor decreases sequentially.

15. The parallel sequenced LED light string of claim 13, It is characterized in that The power supply is a constant current source; When the light emitting diode modules are sequenced sequentially, the resistance of the controllable resistor increases sequentially.

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