CN115379616A - Parallel sequenced light-emitting diode lamp string - Google Patents

Abstract

The invention provides a parallel sequential LED lamp string including several LED modules. Each of the LED modules is connected in parallel through a power line with several line resistances. Each of the LED modules includes 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 resistances and each of the impedance elements, so that the voltages generated on each of the LED modules are different, Sequencing is performed on each of the LED modules.

Description

Parallel sequenced strings of LED lights

technical field

The invention relates to a light-emitting diode lamp string, in particular to a parallel-sequenced light-emitting diode lamp string with impedance compensation technology.

Background technique

Because light-emitting diodes (light-emitting diodes, LEDs) have the advantages of high luminous efficiency, low power consumption, long life, fast response, high reliability, etc., light-emitting diodes have been widely used as light bars Or the connection mode of series, parallel or series-parallel connection of light string (light string), which is applied to lighting lamps or decorative lighting, such as Christmas tree lighting, sports shoes lighting special effects, etc.

Taking festive lighting decorations as an example, a complete LED lighting basically includes a string of LED lights (with several lights) and a driving unit for driving the lights. The drive unit is electrically connected to the light string, and by providing the required power and a control signal with luminous data to the light, it is controlled in a point-controlled or synchronous manner to achieve a variety of light output effects for LED lamps with change.

According to the current technology, in order to drive each of the LEDs of the LED light string to emit light in various ways, each of the LEDs has different address sequence data. Each of the light-emitting diodes receives a light-emitting signal including light-emitting data and address data: if the address sequence data of the light-emitting diode is the same as the address data of the light-emitting signal, the light-emitting diode emits light according to the light-emitting data of the light-emitting signal; The address sequence data of the diode is different from the address data of the light emitting signal, and the light emitting diode skips the light emitting data of the light emitting signal.

At present, the sequencing method of each of the LEDs in the LED light string is mostly complicated or difficult; for example, before each of the LEDs is combined into a LED light string, it is necessary to burn a different address for each LED sequential data. Afterwards, each of the LEDs is sequentially placed according to the address sequence data and combined to form the LED string. If the light emitting diodes are not placed sequentially according to the address sequence data, the diversified lighting of the light emitting diodes cannot be correctly achieved.

Contents of the invention

The purpose of the present invention is to provide a parallel sequenced light string of light emitting diodes, which has impedance compensation technology, so as to solve the problem in the prior art that the address is used as the sequence of light emitting diodes.

In order to achieve the foregoing objectives, the parallel sequenced LED light string proposed by the present invention includes a plurality of LED modules. Each of the LED modules is connected in parallel through power lines with several line resistances. Each LED module includes 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 resistances and each of the impedance elements, so that the voltages generated on each of the LED modules are different, Sequencing is performed on each of the LED modules.

In one embodiment, the generated voltages are compared with several voltage ranges to determine the sequence of the LED modules.

In one embodiment, each of the voltage ranges is established in a look-up table.

In one embodiment, each of the voltage ranges is determined according to the size of the power supply, the number of each of the LED modules, the size of each of the line resistances, and the size of each of the impedance elements.

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

In one embodiment, the voltage generated by the front LED modules is greater than the voltage generated by the rear LED modules.

In one embodiment, the power supply is a constant current source, each of the impedance elements is a controllable resistor with adjustable resistance, and the resistance of the controllable resistor is designed to increase.

In one embodiment, the voltage generated by the front LED modules is smaller than the voltage generated by the rear LED modules.

In one embodiment, the LED light strings sequenced in parallel further include a signal generating unit. The signal generating unit provides a sequence of signals; each of the impedance elements is a controllable resistor with adjustable resistance.

In one embodiment, each of the LED modules determines the order of each of the LED modules according to the cycle sequence of the sequence signal; the power supply is a constant voltage source, and when the sequence of a LED module is completed , turning off the corresponding impedance elements, and reducing the resistance values of the impedance elements corresponding to the unsequenced LED modules.

In one embodiment, each of the LED modules determines the order of each of the LED modules according to the periodic sequence of the sequence signal; the power supply is a constant current source, and when the sequence of a LED module is completed , turning off the corresponding impedance element, and increasing the resistance value of the impedance element corresponding to the unsequenced LED module.

In one embodiment, the LED light strings sequenced in parallel further include a switch unit. The switch unit is connected in series with the controllable resistor.

In one embodiment, each of the LED modules includes a plurality of resistors and a plurality of switch units. Each of the switch units is correspondingly connected in series with each of the plurality of resistors.

In one embodiment, the LED light strings sequenced in parallel further include a compensation unit. The compensation unit is coupled in parallel to the last LED module. The compensation unit includes a controllable resistor with adjustable resistance.

In one embodiment, the power supply is a constant voltage source; when the LED modules are sequenced sequentially, the resistance values of the controllable resistors decrease sequentially.

In one embodiment, the power supply is a constant current source; when the LED modules are sequentially sequenced, the resistance value of the controllable resistors increases sequentially.

With the proposed parallel-sequenced LED strings, the voltage range information provided by the built-in look-up table provides a corresponding search for the detected voltage, and determines the sequence of the LED modules according to the difference in voltage , thereby simplifying the circuit design, quickly completing the sequencing of the light-emitting diode strings, and by using a controllable resistor with adjustable resistance or a parallel design of several resistors or adjusting the resistance of the compensation unit, it is possible to improve the detected The accuracy of comparison, judgment and identification between the received voltage and the voltage range of the lookup table.

Description of drawings

Fig. 1A: The circuit diagram of the first embodiment of the LED light strings connected in parallel and sequenced for the constant voltage source of the present invention.

FIG. 1B : a circuit diagram of a first embodiment of parallel-sequenced LED strings for powering a constant current source of the present invention.

Fig. 2A: The circuit diagram of the second embodiment of the LED light strings connected in parallel and sequenced for the constant voltage source of the present invention.

Fig. 2B: A circuit diagram of a second embodiment of a parallel-sequenced LED string for powering a constant current source of the present invention.

FIG. 3A is a voltage schematic diagram of the first embodiment of the LED light strings connected in parallel and sequenced according to the present invention.

FIG. 3B is a voltage schematic diagram of the second embodiment of the LED light strings connected in parallel and sequenced according to the present invention.

FIG. 4 is a circuit block diagram of an embodiment of a controllable resistance of the present invention.

FIG. 5 is a circuit block diagram of a multi-resistor embodiment of the present invention.

Fig. 6: is the circuit block diagram of the counting operation of the present invention.

In the picture:

10: Power cord; 11, 12,..., 1N: LED module;

R _L1 ,R _L2 ,…,R _LN ,R _L1' ,R _L2' ,…,R _LN' : wire resistance; R ₁ ,R ₂ ,....,R _N : resistance;

C ₁ ,C ₂ ,...,C _N : parasitic capacitance; V ₁ ,V ₂ ,...,V _N :voltage;

Vdc: power supply; Idc: power supply; R11, R21, R22: resistance; Q11, Q21, Q22: switch unit;

31: a voltage stabilizing unit; 32: an analog-to-digital conversion unit.

Detailed ways

The present invention will be 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 examples given are not intended to limit the present invention.

Please refer to FIG. 1A , which is a circuit diagram of a first embodiment of a parallel sequence LED light string powered by a constant voltage source of the present invention. The parallel sequenced LED light strings include several (N) LED modules 11 , 12 , . . . , 1N. Each of the LED modules 11 , 12 , . . . , 1N is connected in parallel through a power line 10 . For the actual circuit, the power line 10 has line resistance, so the power line 10 has several line resistances R _L1 , _RL2 , . . . , R _LN , _{RL1' , RL2'} , . Each of the LED modules 11, 12, ..., 1N includes a resistor R ₁ , R ₂ , ..., R _N , and equivalent and corresponding resistors R ₁ , R ₂ , ..., R _N parallel parasitic capacitances C ₁ , C ₂ ,..., C _N , that is, the first light emitting diode module 11 includes a first resistor R ₁ and parallel first parasitic capacitance C ₁ , the second light emitting diode module 12 The Nth _light emitting diode module 1N includes the second resistor R ₂ and the second parasitic capacitance C ₂ connected in parallel _, .

As shown in FIG. 1A , 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 each of the LED modules 11, 12, ..., 1N via each of the line resistances _RL1 , _RL2 , ..., _RLN , _RL1' , _RL2' , ..., RLN _' Each of the resistors R ₁ , R ₂ , ..., R _N in the internal resistors makes the voltages generated on each of the LED modules 11, 12, ..., 1N different.

When powered on, since the circuits in each of the LED modules 11, 12, ..., 1N have not started and operated, each of the LED modules 11, 12, ..., 1N can be equivalent to the corresponding Resistors R ₁ , R ₂ , . . . , R _N . Furthermore, for the convenience of explanation, the line resistance _RL1 and the line resistance _RL1' can be equivalent to the line resistance _RL1 of a single line, and similarly, the line resistance _RL2 and the line resistance _RL2' are equivalent to the line resistance R of a single line _L2 , ... the line resistance R _LN and the line resistance R _LN' are equivalent to the line resistance R _LN of a single line.

When powered on, the power supply Vdc supplies power to each of the LED modules 11, 12, ..., 1N, and the voltage difference caused by the current flowing through each line resistance R _L1 , R _L2 , ..., R _LN , For this embodiment, the voltage difference caused by the power supply Vdc of the constant voltage source through the wire resistances R _L1 , R _L2 , ..., R _LN is a voltage drop. Therefore, in each of the LED modules 11, 12,...,1N have different voltages. As shown in FIG. 3A , which is a voltage schematic diagram of the first embodiment of the LED lamp string connected in parallel sequence according to the present invention, a first voltage V ₁ on the first LED module 11 is greater than that on the second LED module. A second voltage V ₂ on the group 12, said second voltage V ₂ being greater than a third voltage V ₃ on the third LED module 13, ... and so on, ie, the front (upstream) light emitting The voltage generated by the diode module is greater than the voltage generated by the following (downstream) LED modules (V ₁ >V ₂ >...>V _N ). In this way, each of the light emitting diode modules ₁₁ , _{12 ,} . Hereinafter, the principles of the different sizes of the generated voltages V ₁ , V ₂ , . . . , V _N and the sequence of the LED modules 11, 12, .

In an embodiment, it may be implemented by building a corresponding lookup table (lookup table). For example, the circuit designer can according to the size of the power supply Vdc, the number of each of the LED modules 11, 12,..., 1N, the line resistances R _L1 , R _L2 ,..., R _LN The (estimated) size, and the size of each of the resistors R ₁ , R ₂ ,...,R _N , the look-up table is established in advance for the generated voltages V ₁ , V ₂ ,...,V _N Correspondence, so as to achieve the sequencing of each of the LED modules 11, 12, . . . , 1N.

As shown below, it is an implementation manner of the look-up table, where 100 LED modules 11, 12, . . . , 1N are taken as an example for illustration.

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

When the LED light string is powered on, the power supply Vdc supplies power to each of the LED modules 11, 12, ..., 1N, so the first voltage V ₁ will be generated on the first LED module 11, and the Generating the second voltage V ₂ , . . . on the second LED module 12 generates an Nth voltage V _N on the Nth LED module 1N. For example, when the voltage (such as the first voltage V 1 ) obtained by a certain LED module (such as the first LED module ₁₁ ) is 5.00 volts, since the voltage is between the first lamp sequence (# 1) within the voltage range (5.10-4.90 volts), so the LED modules can be sequenced as the first LED module 11 . Similarly, when the voltage (such as the second voltage V 2 ) obtained by a certain LED module (such as the second LED module ₁₂ ) is 4.80 volts, since the voltage is between the second lamp sequence (#2 ) within the voltage range (4.90~4.70 volts), so the LED module can be sequenced as the second LED module 12. Similarly, when the voltage (such as the sixth voltage V 6 ) obtained by a certain LED module (such as the sixth LED module ₁₆ ) is 4.20 volts, since the voltage is between the sixth lamp sequence (#6 ) voltage range (4.26~4.14 volts), so the LED module can be sequenced as the sixth LED module 16.

In this way, after the LED light string is powered on, it can detect the voltages V ₁ , V ₂ , _. The voltage range of the table can be used to obtain the light sequence of each of the LED modules 11, 12, . . . , 1N. The above-mentioned voltage range is not limited by the exemplified voltage value. For example, it can be based on the size of the power supply Vdc, the number of each of the LED modules 11, 12, ..., 1N, each of the line resistances R _L1 , The (estimated) size of R _L2 ,..., R _LN , the size of each of the resistors R ₁ , R ₂ ,..., _RN , or other parameters, the voltage range of the pre-established look-up table, can realize The corresponding detection voltage should be included in the scope of the present invention.

Please refer to FIG. 1B , which is a circuit diagram of a first embodiment of a parallel sequence LED light string powered by a constant current source of the present invention. In addition to realizing the power supply Vdc as a constant voltage source, the present invention can also be realized as a constant current source, which means that in this embodiment, the power supply Idc is a constant current source (constant current source). To provide a current source with a fixed current magnitude. The power supply Idc is connected to each of the light emitting diode modules 11, 12, ..., 1N via each of the line resistances _RL1 , _RL2 , ..., _RLN , RL1 _' , _RL2' , ..., _RLN' Each of the resistors R ₁ , R ₂ , ..., R _N in the internal resistors makes the voltages generated on each of the LED modules 11, 12, ..., 1N different.

When powered on, since the circuits in each of the LED modules 11, 12, ..., 1N have not started and operated, each of the LED modules 11, 12, ..., 1N can be equivalent to the corresponding Resistors R ₁ , R ₂ , . . . , R _N . Furthermore, for the convenience of explanation, the line resistance _RL1 and the line resistance _RL1' can be equivalent to the line resistance _RL1 of a single line, and similarly, the line resistance _RL2 and the line resistance _RL2' are equivalent to the line resistance R of a single line _L2 , ... the line resistance R _LN and the line resistance R _LN' are equivalent to the line resistance R _LN of a single line.

When powered on, the power supply Idc supplies power to each of the LED modules 11, 12, ..., 1N, and the voltage difference caused by the current flowing through each line resistance R _L1 , R _L2 , ..., R _LN , For this embodiment, the voltage difference caused by the power supply Idc of the constant current source through each line resistance R _L1 , R _L2 ,..., R _LN is a voltage rise. Therefore, in each of the LED modules 11, 12,...,1N have different voltages. As shown in FIG. 3B , which is a voltage schematic diagram of the second embodiment of the LED light string connected in parallel sequence according to the present invention, a first voltage V ₁ on the first LED module 11 is lower than that on the second LED module 11. A second voltage V ₂ on the group 12 , said second voltage V ₂ is lower than a third voltage V ₃ on the third LED module 13 , ... and so on, ie, the front (upstream) light emitting The voltage generated by the diode module is smaller than the voltage generated by the following (downstream) LED modules (V ₁ <V ₂ <...<V _N ). In this way, each of the light emitting diode modules ₁₁ , _{12 ,} . Hereinafter, the principles of the different sizes of the generated voltages V ₁ , V ₂ , . . . , V _N and the sequence of the LED modules 11, 12, .

In an embodiment, it may be implemented by building a corresponding lookup table (lookup table). For example, according to the size of the power supply Idc, the number of each of the LED modules 11, 12, ..., 1N, the line resistances R _L1 , R _L2 , ..., R _LN The (estimated) size, and the size of each of the resistors R ₁ , R ₂ ,...,R _N , the look-up table is established in advance for the generated voltages V ₁ , V ₂ ,...,V _N Correspondence, so as to achieve the sequencing of each of the LED modules 11, 12, . . . , 1N.

As shown below, it is an implementation manner of the look-up table, where 100 LED modules 11, 12, . . . , 1N are taken as an example for illustration.

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

When the light-emitting diode light string is powered on, the power supply Idc supplies power to each of the light-emitting diode modules 11, 12, ..., 1N, so the first voltage V ₁ will be generated on the first light-emitting diode module 11. Generating the second voltage V ₂ , . . . on the second LED module 12 generates an Nth voltage V _N on the Nth LED module 1N. For example, when the voltage (such as the first voltage V 1 ) obtained by a certain LED module (such as the first LED module ₁₁ ) is 2.34 volts, since the voltage is between the first lamp sequence (# 1) within the voltage range (2.36-2.32 volts), so the LED modules can be sequenced as the first LED module 11 . Similarly, when the voltage (such as the second voltage V 2 ) obtained by a certain LED module (such as the second LED module ₁₂ ) is 2.38 volts, since the voltage is between the second lamp sequence (#2 ) within the voltage range (2.40~2.36 volts), so the LED module can be sequenced as the second LED module 12. Similarly, when the voltage (such as the sixth voltage V 6 ) obtained by a certain LED module (such as the sixth LED module ₁₆ ) is 2.64 volts, since the voltage is between the sixth lamp sequence (#6 ) voltage range (2.68~2.60 volts), so the LED module can be sequenced as the sixth LED module 16.

In this way, after the LED light string is powered on, it can detect the voltages V ₁ , V ₂ , _. The voltage range of the table can be used to obtain the light sequence of each of the LED modules 11, 12, . . . , 1N. The above-mentioned voltage range is not limited by the exemplified voltage values. For example, it can be based on the size of the power supply Idc, the number of each of the LED modules 11, 12, ..., 1N, each of the line resistances R _L1 , The (estimated) size of R _L2 ,..., R _LN , the size of each of the resistors R ₁ , R ₂ ,..., _RN , or other parameters, the voltage range of the pre-established look-up table, can realize The corresponding detection voltage should be included in the scope of the present invention.

In the first embodiment shown in FIG. 1A (that is, the power supply mode of a constant voltage source), in order to improve the accuracy of comparison, judgment, and identification between the detected voltage and the voltage range of the look-up table, each institute Each of the resistors R ₁ , R 2 , ..., RN in the LED modules 11, ₁₂ , ..., _1N can be a controllable resistor with adjustable resistance. In addition, when powering on the LED modules 11, 12, ..., 1N to sequence, each of the controllable resistors (that is, each of the resistors R ₁ , R ₂ , ... ,R _N ) is designed to be the minimum resistance value, so that the current flowing through each of the resistors R ₁ , R ₂ ,...,R _N is the largest, so in each of the light-emitting diode modules 11,12,... , the voltages V ₁ , V ₂ , _.

Furthermore, in the application of the circuit, since the power supply Vdc of the constant voltage source is provided, and because of the equivalent resistance effect, the current at the rear is smaller, resulting in a gap between the LED modules at the rear. The voltage difference will be smaller. As shown in FIG. 3A , for example, the voltage difference between the first voltage V ₁ generated on the first LED module and the second voltage V ₂ generated on the second LED module will be greater than the second voltage V ₂ and the voltage difference between the third voltage V ₃ generated on the third LED module (that is, V ₃ -V ₂ <V ₂ -V ₁ ), and the lower LED module between the two The voltage difference will be smaller. Incidentally, as shown in FIG. 1B and FIG. 3B , for the power supply Idc that provides a constant current source, its circuit effect is similar to that of the power supply Vdc that is a constant voltage source, but the effect is opposite. The operation principle of the power supply Vdc of the constant voltage source is also applicable to the power supply Idc of the constant current source, and will not be described in detail, only the operation principle of the power supply Vdc of the constant voltage source will be described. described as follows.

Therefore, in order to avoid the decrease in the accuracy of the comparison, judgment and identification between the detected voltage and the voltage range of the look-up table due to the smaller voltage difference between the LED modules at the rear, the present invention connects them in parallel. The sequenced LED light string maintains the same current by adjusting the resistance value of each of the resistors R ₁ , R ₂ ,..., _RN , so that the voltage difference between any two LED modules maintains Fixed to improve the accuracy of comparison, judgment and identification between the detected voltage and the voltage range of the look-up table. The adopted method is achieved by adjusting the resistance of each of the resistors R ₁ , R ₂ , . . . , R _N through a sequence of signals. The details are as follows.

The sequence signal is a pulse wave 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 considered as the first order, the second cycle as the second order...and so on.

Therefore, when the power is turned on for the first time, because the resistors R ₁ , R ₂ , ... , R _N are connected in parallel, the equivalent resistance value is the smallest, so the current flowing is the largest. The magnitude of the first voltage _V1 corresponding to the first sequence (first period) of the pulse signal can be obtained.

When the first power-on is completed, the first resistor _R1 can be turned off, for example, the resistance value of the first resistor _R1 can be adjusted to a relatively large value, which is like an open circuit for the current, so that the current flowing through the The current of the first resistor _R1 approaches zero, or the switching element connected in series with the first resistor _R1 is turned off, so that the current flowing through the first resistor _R1 is zero, and the second light-emitting diode From the second resistor _R2 of the module 12 to the resistor of the last light-emitting diode module (for example, the 100th resistor), that is, the resistance values of the remaining 99 resistors are all reduced, for example but not limited to 1/ of the original resistance value 100. Therefore, since the resistance values of the remaining resistors are all reduced, the equivalent resistance values after parallel connection will be the same, so that the flowing currents will be the same. When the power is turned on again, the magnitude of the second voltage _V2 corresponding to the second sequence (second cycle) of the pulse signal can be obtained.

Similarly, when the second power-on ends, both the first resistor _R1 and the second resistor _R2 can be turned off, for example, the resistance values of the first resistor _R1 and the second resistor _R2 can be adjusted to A relatively large value is like an open circuit for the current, making the current flowing through the first resistor _R1 and the second resistor _R2 approach to zero, and the third resistor _R3 of the third LED module 12 Up to the resistor of the last LED module (for example, the 100th resistor), that is, the resistance values of the remaining 98 resistors are all reduced, for example but not limited to 1/100 of the previous resistance value. Therefore, since the resistance values of the remaining resistors are all reduced, the equivalent resistance values after parallel connection will be the same, so that the flowing currents will be the same. When the power is turned on again, the magnitude of the third voltage _V3 corresponding to the third sequence (third cycle) of the pulse signal can be obtained. In this way, 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 same current, so that the voltage difference between any two LED modules can be kept constant, so as to improve the detection efficiency. The accuracy of comparison, judgment and identification between the measured voltage and the voltage range of the look-up table.

Compared with the constant voltage power supply in Figure 1A, the impedance compensation of the constant current power supply in Figure 1B is to increase the resistance value of the remaining resistors, so that the equivalent resistance value after parallel connection will increase, so that the flow through The current becomes smaller. In this way, the sequence signal can be used as the basis of the sequence, and the resistance value of the remaining resistor can be adjusted (increased) to maintain the same current, so that the voltage difference between any two LED modules can be kept constant, so as to improve the detection efficiency. The accuracy of comparison, judgment and identification between the measured voltage and the voltage range of the look-up table.

Please refer to FIG. 2A and FIG. 2B , which are respectively the circuit diagram of the second embodiment of the parallel sequenced LED lamp string powered by the constant voltage source of the present invention and the parallel sequenced LED lamp powered by the constant current source of the present invention. Circuit diagram of the second embodiment of the string. For the convenience of description, also take the example of FIG. 2A and FIG. 3A that provide a constant voltage source, and is applicable to the power supply Idc that provides a constant current source in FIG. 2B . The operating principle of the power supply Vdc described above is explained as follows.

The biggest difference between the LED light string shown in FIG. 2A and the LED light string shown in FIG. 1A is: the resistance value of each LED module 11, 12, ..., 1N in the LED light string shown in FIG. 2A It does not have the controllable characteristics as shown in Figure 1A, that is, in order to achieve the effect of resistance compensation, the LED light string shown in Figure 2A also includes a compensation unit 20, which is used to replace each LED module as shown in Figure 1A Controllable adjustment of resistance values within groups 11, 12, ..., 1N. In other words, the compensation method with adjustable resistance (that is, controllable resistance) implemented in FIG. 1A and FIG. 1B will be realized by the compensation unit 20, so that not only the circuit control can be simplified, but also the circuit cost can be saved. Wherein, the compensation unit 20 is an integrated circuit (IC), which has a counting function, or the compensation unit 20 is a circuit formed by a ratio circuit and a digital circuit, which has a counting function.

When the power is turned on for the first time, because the resistors R ₁ , R ₂ , ... , R _N are connected in parallel, the equivalent resistance value is the smallest, so the flowing current is the largest. The magnitude of the first voltage _V1 corresponding to the first sequence (first period) of the pulse signal can be obtained.

When the first power-on ends, the first resistor _R1 can be turned off, and the impedance of the compensation unit 20 can be reduced by controlling (that is, the impedance compensation of the compensation unit 20), so that the equivalent resistance value after parallel connection will be the same, This allows the same current to flow. When the power is turned on again, the magnitude of the second voltage _V2 corresponding to the second sequence (second cycle) of the pulse signal can be obtained.

Similarly, when the second power-on ends, both the first resistor R ₁ and the second resistor R ₂ can be turned off, and the impedance of the compensation unit 20 can be controlled to reduce again, so that the equivalent resistance value after parallel connection will be Same, that is, when both the first resistor _R1 and the second resistor _R2 are turned off, the impedance of the compensation unit 20 will be smaller than the impedance when only the first resistor _R1 is turned off (that is, the impedance compensation of the compensation unit 20), so that the flowing same current. When the power is turned on again, the magnitude of the third voltage _V3 corresponding to the third sequence (third cycle) of the pulse signal can be obtained. In this way, the sequence signal can be used as the basis for the sequence, and the impedance of the compensation unit 20 can be adjusted (reduced) to maintain a consistent current, so that the voltage difference between any two LED modules remains constant, so as to improve the detected The accuracy of the voltage identification.

Compared with the constant voltage power supply in FIG. 2A , the impedance compensation of the constant current power supply in FIG. 2B is to increase the resistance value of the compensation unit 20, so that the equivalent resistance value after parallel connection will increase, so that the flowing current get smaller. In this way, the sequence signal can be used as the basis of the sequence, and the way of adjusting (increasing) the resistance of the compensation unit 20 can be used to maintain the same current, so that the voltage difference between any two LED modules can be kept constant, so as to improve the Accuracy of detected voltage identification.

Please refer to FIG. 4 , which is a circuit block diagram of a controllable resistance embodiment of the present invention. As mentioned above, the resistors R ₁ , R ₂ , . . . , _RN of each of the LED modules 11 , 12 , . Furthermore, the controllable resistor R11 is connected in series with a switch unit Q11 , such as but not limited to a transistor switch. In this way, by adjusting the resistance value 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 each of the luminescent The voltages V ₁ , V ₂ , ..., V _N generated on the diode modules 11, 12, ..., 1N can be maximized, thereby improving the comparison, judgment, and The accuracy of the identification can be adjusted, or by adjusting the resistance value of the controllable resistor R11 to a relatively large value, or turning off the switch unit Q11, so that the current flowing through the controllable resistor R11 approaches zero Or equal to zero, so as to keep the current consistent, so that the voltage difference between any two LED modules remains constant, so as to improve the accuracy of comparison, judgment and identification between the detected voltage and the voltage range of the look-up table.

Please refer to FIG. 5 , which is a circuit block diagram of a multi-resistor embodiment of the present invention. Compared with the controllable resistor with adjustable resistance shown in FIG. 4 , the present invention can also achieve different resistance designs by connecting multiple resistors in parallel (two resistors R21 and R22 as shown in the figure). Each of the resistors R21, R22 is correspondingly connected in series with a switch unit Q21, Q22, 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 two resistors R21, R22 and two switch units Q21, Q22 as an example, if a smaller resistance value is to be generated, the resistors R21, R22 can be connected in parallel by turning on the switch units Q21, Q22. To generate a larger resistance value, at least one switch unit Q21, Q22 can be turned off, or even both switch units Q21, Q22 can be turned off at the same time, so that the state is equivalent to an open circuit. In this way, it is also possible to improve the accuracy of the comparison, judgment and identification between the detected voltage and the voltage range of the look-up table, as well as maintain the consistency of the current, so that the voltage difference between any two LED modules remains constant. , so as to improve the accuracy of comparison, judgment and identification between the detected voltage and the voltage range of the look-up table. In addition, a voltage stabilizing unit 31 and an analog-to-digital converting unit 32 are also included. The voltage stabilizing unit 31 is coupled in parallel with each of the resistors R21, R22 and each of the switching units Q21, Q22 to provide a voltage stabilizing operation. The analog-to-digital conversion unit 32 is coupled to the voltage stabilizing unit 31 for converting an analog signal into a digital signal.

Please refer to FIG. 6 , which is a circuit block diagram of the counting operation of the present invention, and is also a block diagram of a compensation unit, which is used to realize a compensation method with adjustable resistance (that is, controllable resistance).

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

1. Through the voltage range information provided by the built-in lookup table, provide the corresponding search for the detection voltage, and determine the light sequence of the LED module according to the difference in voltage, so as to simplify the circuit design and quickly complete the light emission Sequencing of diode strings.

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 comparison, judgment and identification of the detected voltage and the voltage range of the look-up table can be improved. Accuracy.

The above-mentioned 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 transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention shall be determined by the claims.

Claims (16)

1. A parallel sequenced light emitting diode light string comprising:

the LED modules are connected in parallel through a power line with a plurality of line resistors, and each LED module comprises an impedance element capable of providing impedance characteristics;

the LED modules connected in parallel receive a power supply, and the power supply makes the voltages generated on the LED modules different in magnitude through the wire resistors and the impedance elements, so as to sequence the LED modules.

2. The parallel sequenced led light string of claim 1 wherein each of said generated voltage levels is compared to a plurality of voltage ranges to determine the sequence of each of said led modules.

3. The parallel sequenced led light string of claim 2 wherein each of said voltage ranges is established in a look-up table.

4. The parallel sequenced led light string of claim 2 wherein each of said voltage ranges is determined by the size of said power supply, the number of said led modules, the size of said wire resistors, and the size of said impedance elements.

5. The parallel sequenced led light string of claim 1 wherein said power supply is a constant voltage source;

each impedance element is a controllable resistor with adjustable resistance value, and the resistance value of the controllable resistor is designed in a reducing way.

6. The parallel sequenced led light string of claim 5 wherein the voltage generated by a preceding led module is greater than the voltage generated by a subsequent led module.

7. The parallel sequenced led light string of claim 1 wherein said power supply is a source of current;

each impedance element is a controllable resistor with adjustable resistance value, and the resistance value of the controllable resistor is designed to be increased.

8. The parallel sequenced led light string of claim 7 wherein the voltage generated by a preceding led module is less than the voltage generated by a following led module.

9. The parallel sequenced led light string as described in claim 1 further comprising:

a signal generating unit for providing a sequence signal;

wherein each impedance element is a controllable resistor with adjustable resistance.

10. The parallel sequenced led light string of claim 9 wherein each of said led modules sequences according to a periodic sequence of said sequence signal; the power supply is a certain voltage source, and when sequencing of one light-emitting diode module is completed, the corresponding impedance element is closed, and the resistance value of the impedance element corresponding to the light-emitting diode module which is not sequenced is reduced.

11. The parallel sequenced led light string of claim 9 wherein each of said led modules sequences according to a periodic sequence of said sequence signal; the power supply is a certain current source, and after sequencing of one light-emitting diode module is completed, the corresponding impedance element is closed, and the resistance value of the impedance element corresponding to the light-emitting diode module which is not sequenced is increased.

12. The parallel sequenced led light string of claim 9 further comprising:

and the switching unit is connected in series with the controllable resistor.

13. The parallel sequenced led light string of claim 1 wherein each of said led modules comprises:

a plurality of resistors; and

and the switch units are correspondingly connected in series with the resistors.

14. The parallel sequenced led light string as described in claim 1 further comprising:

a compensation unit coupled in parallel with the last LED module;

wherein, the compensation unit comprises a controllable resistor with adjustable resistance.

15. The parallel sequenced led light string of claim 14 wherein said power supply is a constant voltage source;

when the light emitting diode modules are sequenced in sequence, the resistance values of the controllable resistors are reduced in sequence.

16. The parallel sequenced light-emitting diode light string as described in claim 14 wherein said power supply is a constant current source;

when the light emitting diode modules are sequenced in sequence, the resistance value of the controllable resistor is increased in sequence.

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