TWI767698B - Parallel sequenced led light string - Google Patents

Abstract

A parallel sequenced LED light string includes a plurality of LED modules. The LED modules are connected in parallel through a power wire with a plurality of wire resistances. Each LED module includes an impedance component capable of providing an impedance characteristic. The parallel-connected LED modules receive a supply power, and the supply power generates different voltages on each of the LED modules through the wire resistances and the impedance components so as to sequence the LED modules.

Description

Light-emitting diode light string sequenced in parallel

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

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

Taking festival lighting as an example, a complete LED lighting basically includes a LED string (having a plurality of lamps) and a driving unit for driving the lamps. The driving unit is electrically connected to the light string, and is controlled in a point-controlled manner or a synchronous manner by supplying the required power and a control signal with luminous data to the light to realize various light output effects of the light-emitting diode lamps. with change.

According to the current technology, in order to drive the light-emitting diodes of the light-emitting diode light string to emit light in a diversified manner, the light-emitting diodes have different address sequence data. The light-emitting diodes receive light-emitting signals including light-emitting data and address data: if the address sequence data of the light-emitting diodes is the same as the address data of the light-emitting signal, the light-emitting diodes emit light according to the light-emitting signal The data emits light; if the address sequence data of the light-emitting diode is different from the address data of the light-emitting signal, the light-emitting diode skips the light-emitting data of the light-emitting signal.

At present, the sequencing methods of the LEDs of the LED light string are mostly complicated or difficult; The diodes are programmed with different address sequence data. Afterwards, the light emitting diodes are sequentially placed according to the address sequence data and assembled into the light emitting diode light string. If the light emitting diodes are not placed sequentially according to the address sequence data, the diversified light emission of the light emitting diodes cannot be correctly achieved.

Therefore, how to design a parallel sequenced LED light string with impedance compensation technology to solve the problems in the prior art is an important subject studied by the inventor of the present application.

The purpose of the present invention is to provide a parallel sequenced LED light string, which solves the problem existing in the prior art that addresses are used as LED sequencers.

In order to achieve the aforementioned purpose, the parallel sequenced LED light string provided by the present invention includes a plurality of LED modules. The light-emitting diode modules are connected in parallel through power lines with a plurality of line resistances. Each light-emitting diode module includes an impedance element that can provide impedance characteristics. The light-emitting diode modules connected in parallel receive a power supply, and the power supply is passed through the line resistances and the impedance elements, so that the voltages generated on the light-emitting diode modules are different in magnitude. The LED modules are sequenced.

In one embodiment, the magnitudes of the generated voltages are compared with a plurality of voltage ranges to determine the order of the LED modules.

In one embodiment, the voltage ranges are established in a look-up table.

In one embodiment, the voltage ranges are determined according to the size of the power supply, the number of the light-emitting diode modules, the size of the line resistances, and the size of the impedance elements.

In one embodiment, 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.

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

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

In one embodiment, the voltage generated by the front LED module is lower than the voltage generated by the rear LED module.

In one embodiment, the LED light string sequenced in parallel further includes 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, the light-emitting diode modules determine the order of the light-emitting diode modules according to the periodic sequence of the sequence signal; After sequencing, 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.

In one embodiment, the light-emitting diode modules determine the sequence of the light-emitting diode modules according to the periodic order of the sequence signal; After sequencing, 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.

In one embodiment, the parallel sequenced LED light string further includes a switch unit. The switch unit is connected in series with the controllable resistance.

In one embodiment, each of the light emitting diode modules includes a plurality of resistors and a plurality of switch units. The switch units are correspondingly connected in series with the complex resistors.

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

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

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

Through the proposed parallel sequenced LED light string, through the voltage range information provided by the built-in lookup table, the corresponding search of the detection voltage is provided, and the LED mode is determined according to the difference in voltage size The light sequence of the group can simplify the circuit design, quickly complete the sequence of the LED light string, and through the use of controllable resistors with adjustable resistance or the parallel design of complex resistors or the adjustment of the resistance of the compensation unit, The accuracy of comparing, judging and identifying the detected voltage and the voltage range of the look-up table can be improved.

In order to further understand the technology, means and effect adopted by the present invention to achieve the predetermined purpose, please refer to the following detailed description of the present invention and the accompanying drawings. It is believed that the purpose, features and characteristics of the present invention can be obtained in depth and specific from this. It is understood that, however, the accompanying drawings are only provided for reference and illustration, and are not intended to limit the present invention.

10: Power cord

11,12,…,1N: LED module

R _L1 ,R _L2 ,…,R _LN ,R _L1' ,R _L2' ,…,R _LN' : Line 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: Resistors

Q11, Q21, Q22: switch unit

31: Voltage Stabilizer Unit

32: Analog-to-digital conversion unit

FIG. 1A is a circuit diagram of a first embodiment of a parallel sequenced LED light string powered by a constant voltage source according to the present invention.

FIG. 1B is a circuit diagram of a first embodiment of a parallel sequenced LED light string powered by a constant current source according to the present invention.

2A is a circuit diagram of a second embodiment of a parallel sequenced LED light string powered by a constant voltage source according to the present invention.

2B is a circuit diagram of a second embodiment of a parallel sequenced LED light string powered by a constant current source according to the present invention.

3A is a schematic diagram of the voltage of the first embodiment of the parallel sequenced light-emitting diode light string of the present invention.

FIG. 3B is a schematic diagram of the voltage of the second embodiment of the light-emitting diode light string sequenced in parallel according to the present invention.

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

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

FIG. 6 is a circuit block diagram of the counting operation of the present invention.

The technical content and detailed description of the present invention are described as follows in conjunction with the drawings.

Please refer to FIG. 1A , which is a circuit diagram of a first embodiment of a parallel sequenced LED light string powered by a constant voltage source according to the present invention. The light-emitting diode light string sequenced in parallel includes a plurality (N) of light-emitting diode modules 11, 12, . . . , 1N. The LED modules 11 , 12 , . . . , 1N are connected in parallel through a power line 10 . For the actual line, the power line 10 has a wire resistance, so the power line 10 has a complex number of line resistances R _L1 , R _L2 ,...,R _LN ,R _L1' ,R _L2' ,...,R _LN' . Each _of the light _{- emitting diode} modules ₁₁ , ₁₂ , . Parasitic capacitances C ₁ , C ₂ , . . . , _CN , that is, the first LED module 11 includes a first resistor R ₁ and a first parasitic capacitance C ₁ in parallel, and the second LED module 12 includes The second resistor R ₂ and the parallel second parasitic capacitor C ₂ , . . . The Nth light-emitting diode module 1N includes the Nth resistor R _N and the parallel Nth parasitic capacitor C _N .

As shown in FIG. 1A , the light-emitting diode modules 11 , 12 , . . . , 1N connected in parallel receive a power supply Vdc. In this embodiment, the power supply Vdc is a constant voltage source for providing a voltage source with a fixed voltage. The power supply _Vdc is _connected to the _{LED modules 11} , ₁₂ , . The _resistors R ₁ , R ₂ , .

At power-on, since the circuits in each of the LED modules 11, 12, . Corresponding resistors R ₁ , R ₂ , . . . , R _N . Furthermore, for the convenience of description, the line resistance R _L1 and the line resistance R _L1' can be equivalent to the line resistance R _L1 of a single line, and similarly, the line resistance R _L2 and the line resistance R _L2' 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 the LED modules 11, 12,..., 1N. Due to the voltage difference caused by the current flowing through the line resistances R _L1 , R _L2 ,..., R _LN , the In the embodiment, the voltage difference caused by the power supply Vdc of the constant voltage source through the line resistances R _L1 , R _L2 , . . . , R _LN is the voltage drop. ,…,1N produces different voltages. As shown in FIG. 3A , which is a schematic diagram of the voltage of the first embodiment of the LED light string sequenced in parallel according to the present invention, a first voltage V ₁ on the first LED module 11 is greater than that on A second voltage V ₂ on the second LED module 12 , the second voltage V ₂ is greater than a third voltage V ₃ on the third LED module 13 , . . . and so on, meaning 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 ). In this way, according to the different magnitudes of the generated voltages V ₁ , _{V 2} , . In the following, the principle of _sequencing the LED modules ₁₁ , ₁₂ , .

In one embodiment, it can be implemented by means of a built-in corresponding lookup table. For example, the circuit designer can determine the size of the power supply _Vdc , the number of the light-emitting _diode modules 11, ₁₂ , . _{Estimate )} size, and the size _of the resistors R ₁ , _{R 2} , . Sequencing of the LED modules 11, 12, . . . 1N.

As shown below, it is an embodiment of the look-up table, in which 100 light-emitting diode modules 11, 12, . . . , 1N are used as an example for description.

When the LED light string is powered on, the power supply Vdc supplies power to the LED modules 11 , 12 , . . . , 1N, so a first voltage is generated on the first LED module 11 V ₁ , will generate the second voltage V ₂ on the second light emitting diode module 12 , . . . will generate the N th voltage V _N on the N th light emitting diode module 1N. For example, when the voltage (eg, the first voltage V ₁ ) obtained by a certain LED module (eg, the first LED module 11 ) is 5.00 volts, because the voltage is between the first lamp Therefore, the LED module can be sequenced as the first LED module 11 . Similarly, when the voltage (eg, the second voltage V ₂ ) obtained by a certain LED module (eg, the second LED module 12 ) is 4.80 volts, since the voltage is between the second lamp sequence (#2) is 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 (eg, the sixth voltage V ₆ ) obtained by a certain LED module (eg, the sixth LED module 16 ) is 4.20 volts, because the voltage is between the sixth lamp sequence (#6) is within the voltage range (4.26~4.14 volts), so the LED module can be sequenced as the sixth LED module 16 .

Therefore, after the LED light string is powered on, the voltages V ₁ , V ₂ ,..., V _N generated by the LED modules 11 , 12 , . . . , 1N can be detected, corresponding to The voltage range of the built-in look-up table can be used to obtain the lamp sequence of each of the LED modules 11, 12, . . . , 1N. However, the above voltage range is not limited by the exemplified voltage values. For example, it can be determined according to the size of the power supply Vdc, the number of the light-emitting diode modules 11, 12, . . . , 1N, the line resistance R _L1 , The (estimated) size of R _L2 ,…,R _LN , the size of these resistors R ₁ , R ₂ ,…., R _N , or other parameters, the voltage range of the pre-established look-up table, can realize the detection voltage The correspondence 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 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 for A current source with a fixed current size is provided. The power supply Idc passes through the line resistances R _L1 , R _L2 ,..., R _LN , R _L1' , R _L2' ,..., R _LN' and the LED modules 11, 12,..., 1N The _resistors R ₁ , R ₂ , .

At power-on, since the circuits in each of the LED modules 11, 12, . Corresponding resistors R ₁ , R ₂ , . . . , R _N . Furthermore, for the convenience of description, the line resistance R _L1 and the line resistance R _L1' can be equivalent to the line resistance R _L1 of a single line, and similarly, the line resistance R _L2 and the line resistance R _L2' 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 the LED modules 11, 12, ..., 1N. Due to the voltage difference caused by the current flowing through the line resistances R _L1 , R _L2 , ..., R _LN , the In an embodiment, the voltage difference caused by the power supply Idc of the constant current source through the line resistances R _L1 , R _L2 , . . . , R _LN is the voltage rise. ,…,1N produces different voltages. 3B, which is a schematic diagram of the voltage of the second embodiment of the LED light string sequenced in parallel according to the present invention, a first voltage V1 on the _first LED module 11 is smaller than that on A second voltage V ₂ on the second LED module 12 , the second voltage V ₂ is smaller than a third voltage V ₃ on the third LED module 13 , . . . and so on, meaning 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 ). In this way, according to the different magnitudes of the generated voltages V ₁ , _{V 2} , . In the following, the principle of _sequencing the LED modules ₁₁ , ₁₂ , .

In one embodiment, it can be implemented by means of a built-in corresponding lookup table. For example, the circuit designer can determine the size of the power supply _Idc , the _number of the light-emitting diode modules 11, ₁₂ , . _{Estimate )} size, and the size _of the resistors R ₁ , _{R 2} , . Sequencing of the LED modules 11, 12, . . . 1N.

As shown below, it is an embodiment of the look-up table, in which 100 light-emitting diode modules 11, 12, . . . , 1N are used as an example for description.

When the LED light string is powered on, the power supply Idc supplies power to the LED modules 11 , 12 , . . . , 1N, so a first voltage is generated on the first LED module 11 V ₁ , will generate the second voltage V ₂ on the second light emitting diode module 12 , . . . will generate the N th voltage V _N on the N th light emitting diode module 1N. For example, when the voltage (eg, the first voltage V ₁ ) obtained by a certain LED module (eg, the first LED module 11 ) is 2.34 volts, because the voltage is between the first lamp Therefore, the LED module can be sequenced as the first LED module 11 . Similarly, when the voltage (eg, the second voltage V ₂ ) obtained by a certain LED module (eg, the second LED module 12 ) is 2.38 volts, because the voltage is between the second lamp sequence (#2) is 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 obtained by a certain LED module (eg, the sixth LED module 16 ) (eg, the sixth voltage V ₆ ) is 2.64 volts, because the voltage is between the sixth lamp sequence (#6) is within the voltage range (2.68~2.60 volts), so the LED module can be sequenced as the sixth LED module 16 .

Therefore, after the LED light string is powered on, the voltages V ₁ , V ₂ ,..., V _N generated by the LED modules 11 , 12 , . . . , 1N can be detected, corresponding to The voltage range of the built-in look-up table can be used to obtain the lamp sequence of each of the LED modules 11, 12, . . . , 1N. However, the above-mentioned voltage range is not limited by the exemplified voltage values. For example, it can be determined according to the size of the power supply Idc, the number of the LED modules 11, 12, . . . , 1N, the line resistance R _L1 , The (estimated) size of R _L2 ,…,R _LN , the size of these resistors R ₁ , R ₂ ,…., R _N , or other parameters, the voltage range of the pre-established look-up table, can realize the detection voltage The correspondence 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 the 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 of the Each of the resistors R ₁ , R ₂ , . . . , R _N in the light-emitting diode modules 11 , 12 , . In addition, when the light _- emitting diode modules ₁₁ , ₁₂ , . ) is designed to be the minimum value, so that the current flowing through each of the resistors R ₁ , R ₂ ,…., R _N is the largest, so the current generated on each of the light-emitting diode modules 11, 12,…, 1N _The voltages _V1 , _V2 , .

Furthermore, in circuit applications, since the power supply Vdc of the constant voltage source is provided, and because of the relationship of the equivalent resistance effect, the current at the back is smaller, resulting in the gap between the LED modules at the back. The voltage difference will be smaller. As shown in FIG. 3A , for example, the voltage difference between the first voltage V1 generated on the _first LED module and the _second voltage V2 generated on the second LED module will be greater than The voltage difference between the second voltage V ₂ and the third voltage V ₃ generated on the third LED module (ie, V ₃ -V ₂ <V ₂ -V ₁ ), and the further back LEDs are The voltage difference between the two bulk modules will be smaller. Incidentally, as shown in FIG. 1B and FIG. 3B , the circuit effect of the power supply Idc that provides a constant current source is similar to that of the power supply Vdc of a constant voltage source, but the effect is opposite. The operation principle of the power supply Vdc of the source is also applicable to the power supply Idc that provides a constant current source, and will not be repeated here.

Therefore, in order to avoid the decrease in the accuracy of comparing, judging, and identifying 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, this The invention of the parallel sequenced LED light string maintains the same current by _adjusting the resistance values of the resistors R ₁ , R ₂ , . The voltage difference is kept 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 value of each of the resistors R ₁ , R ₂ , . . . , R _N through a series of signals. The specific description is as follows.

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 the basis for the sequence. That is, the first cycle can be regarded as the first order, the second cycle can be regarded 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 , . The magnitude of the first voltage V ₁ corresponding to the first sequence (first cycle) of the pulse signal can be obtained.

When the first power-on is completed, the first resistor R ₁ can be turned off, for example, the resistance value of the first resistor R ₁ can be adjusted to a relatively large value, which is like an open circuit for the current, so that the first resistor R 1 flows through the first resistor R 1 . _The current of the 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 module 12 From the second resistor R ₂ to the resistance of the last LED module (such as the 100th resistor), that is, the resistance values of the remaining 99 resistors are reduced, such as but not limited to 1/100 of the original resistance value . Therefore, since the resistance values of the remaining resistors are reduced, the equivalent resistance values after parallel connection will be the same, so that the flowing currents can be the same. When powered on again, the magnitude of the second voltage V ₂ corresponding to the second sequence (second cycle) of the pulse signal can be obtained.

Similarly, when the second power-on is completed, 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 be relatively large The value of , acts as an open circuit for the current, so that the current flowing through the first resistor R ₁ and the second resistor R ₂ is close to zero, and the third resistor R ₃ of the third light-emitting diode module 12 is connected to The resistance of the last LED module (for example, the 100th resistance), that is, the resistances of the remaining 98 resistances are reduced, for example but not limited to 1/100 of the previous resistances. Therefore, since the resistance values of the remaining resistors are reduced, the equivalent resistance values after parallel connection will be the same, so that the flowing currents can 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 for the sequence, and the resistance value of the remaining resistors can be adjusted (reduced) to keep the current consistent, so that the voltage difference between any two light-emitting diode modules can be kept constant, so as to improve the The accuracy of comparing, judging, and identifying the detected voltage and the voltage range of the look-up table.

Compared with the constant voltage power supply shown in FIG. 1A , the impedance compensation of the constant current power supply shown in FIG. 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 The current becomes smaller. In this way, the sequence signal can be used as the basis for the sequence, and the resistance value of the remaining resistors can be adjusted (increased) to maintain the same current, so that the voltage difference between any two light-emitting diode modules can be kept constant, so as to improve the The accuracy of comparing, judging, and identifying the detected voltage and the voltage range of the look-up table.

Please refer to FIG. 2A and FIG. 2B , which are the circuit diagrams of the second embodiment of the parallel sequenced LED light string powered by the constant voltage source of the present invention and the parallel sequenced circuit diagram of the constant current source powered by the present invention, respectively. The circuit diagram of the second embodiment of the LED light string. 2A and 3A which provide a constant voltage source are also taken as examples for the convenience of description, and can be applied to the power supply Idc which provides a constant current source in FIG. The principle of operation of the power supply Vdc is explained below.

The biggest difference between the light-emitting diode light string shown in FIG. 2A and the light-emitting diode light string shown in FIG. 1A is that each light-emitting diode module 11 , 12 in the light-emitting diode light string shown in FIG. 2A is , . To replace the controllable adjustment of the resistance value in each light-emitting diode module 11 , 12 , . . . , 1N as shown in FIG. 1A . In other words, the compensation method with adjustable resistance (ie, controllable resistance) implemented in FIG. 1A and FIG. 1B will be realized by the compensation unit 20 , so not only can the circuit control be simplified, but also the circuit cost can be saved. Wherein, the compensation unit 20 is an integrated circuit (IC), It has a counting function, or the compensation unit 20 is a circuit formed by a ratio circuit and a digital circuit, and has a counting function.

When the power is turned on for the first time, because the _resistors R ₁ , R ₂ , . The magnitude of the first voltage V ₁ corresponding to the first sequence (first cycle) of the pulse signal can be obtained.

When the first power-on is completed, the _first resistor R1 can be turned off and the impedance of the compensation unit 20 (that is, the impedance compensation of the compensation unit 20) can be reduced by control, so that the equivalent resistance value after parallel connection will be the same, so The current that flows can be made the same. When powered on again, the magnitude of the second voltage V ₂ corresponding to the second sequence (second cycle) of the pulse signal can be obtained.

Similarly, when the second power-on is completed, 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 reduced by control, so that the equivalent resistance value after parallel connection will be the same , that is, when both the first resistor R ₁ and the second resistor R ₂ are turned off, the impedance of the compensation unit 20 will be smaller than the impedance when only the first resistor R ₁ is turned off (ie, the impedance compensation of the compensation unit 20 ), so that the current flowing through 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 for the sequence, and the impedance of the compensation unit 20 can be adjusted (reduced) to keep the current consistent, so that the voltage difference between any two light-emitting diode modules remains fixed, so as to improve the detection rate. The accuracy of the measured voltage identification.

Compared with the constant voltage power supply shown in FIG. 2A , the impedance compensation of the constant current power supply shown 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 current flowing through it can be increased. become smaller. In this way, the sequence signal can be used as the basis for the sequence, and the resistance value of the compensation unit 20 can be adjusted (increased) to keep the current consistent, so that the voltage difference between any two light-emitting diode modules remains fixed, so that the Improve the accuracy of the detected voltage identification.

Please refer to FIG. 4 , which is a circuit block diagram of an embodiment of the controllable resistance of the present invention. As mentioned above, the resistors R ₁ , R ₂ , . . , _RN of each of the light-emitting diode 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, the resistance value of the controllable resistor R11 can be adjusted 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. Therefore, in each of the light-emitting diodes The voltages V ₁ , V ₂ , ..., V _N generated on the modules 11 , 12 , . 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 tends to be zero or equal to zero. The maintaining current is consistent, so that the voltage difference between any two light-emitting diode modules is kept constant, so as to improve the accuracy of comparing, judging, and identifying 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 value shown in FIG. 4 , the present invention can also achieve the design of different resistance values by connecting multiple resistors in parallel (two resistors R21 and R22 as shown in the figure). Each of the resistors R21 and R22 is respectively connected to a switch unit Q21 and Q22 in series, that is, the resistor R21 is connected to the switch unit Q21 in series, and the resistor R22 is connected to the switch unit Q22 in series. Taking two resistors R21, R22 and two switch units Q21, Q22 as an example, to generate a smaller resistance value, the switch units Q21, Q22 can be turned on, so that the resistors R21, R22 are connected in parallel. 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, the above-mentioned comparison, judgment, and identification accuracy of the detected voltage and the voltage range of the look-up table can also be improved, and the current is kept consistent, so that the voltage difference between any two light-emitting diode modules can be improved. Keep it fixed to improve the accuracy of comparing, judging, and identifying the detected voltage and the voltage range of the look-up table. In addition, a voltage regulator unit 31 and an analog digital conversion unit 32 are further included. The voltage-stabilizing unit 31 is coupled in parallel with the resistors R21 and R22 and the switching units Q21 and Q22 to provide voltage-stabilizing operations. The analog-to-digital conversion unit 32 is coupled to the voltage regulator unit 31, and is used for converting analog signals into digital signals.

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

To sum up, the present invention has the following features and advantages:

1. Through the voltage range information provided by the built-in look-up table, the corresponding search of the detection voltage is provided, and the lamp sequence of the LED module is determined according to the difference of the voltage, which can simplify the circuit design and quickly Complete the sequencing of the LED string.

2. By using a controllable resistance with adjustable resistance or a parallel design of a complex number of resistances or the resistance adjustment 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 descriptions are only detailed descriptions and drawings of the preferred embodiments of the present invention, but the features of the present invention are not limited thereto, and are not intended to limit the present invention. The entire scope of the present invention should be defined as the following claims All the embodiments that conform to the spirit of the scope of the patent application of the present invention and similar variations thereof shall be included in the scope of the present invention. Modifications can be covered by the following patent scope of this case.

10: Power cord

11,12,…,1N: LED module

R _L1 ,R _L2 ,…,R _LN ,R _L1' ,R _L2' ,…,R _LN' : Line 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

Claims (16)

A parallel sequenced light-emitting diode light string, comprising: a plurality of light-emitting diode modules connected in parallel through a power supply line having a plurality of line resistances, each of the light-emitting diode modules including an impedance capable of providing impedance characteristics Components; wherein, the light-emitting diode modules connected in parallel receive a power supply, and the power supply passes through the line resistances and the impedance elements, so that the voltage generated on each of the light-emitting diode modules If the sizes are different, the LED modules are sequenced to determine the sequence of the LED modules. The LED light string sequenced in parallel as claimed in claim 1, wherein the magnitudes of the generated voltages are compared with a plurality of voltage ranges to determine the sequence of the LED modules. The parallel sequenced LED light string of claim 2, wherein the voltage ranges are established in a look-up table. The parallel sequenced LED light string as claimed in claim 2, wherein the voltage ranges are based on the size of the power supply, the number of the LED modules, the size of the line resistance, and The size of these impedance elements is determined. The light-emitting diode light string sequenced in parallel as claimed in claim 1, wherein the power supply is a certain voltage source; each of the impedance elements is a controllable resistor with adjustable resistance, and the design is reduced in size. The resistance value of the resistor can be controlled. The LED light string sequenced in parallel according to claim 5, wherein the voltage generated by the front LED modules is greater than the voltage generated by the latter LED modules. The light-emitting diode light string sequenced in parallel according to claim 1, wherein the power supply is a certain 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. The LED light string sequenced in parallel as claimed in claim 7, wherein the voltage generated by the front LED modules is lower than the voltage generated by the latter LED modules. The parallel sequenced light emitting diode light string as claimed in claim 1 further comprises: a signal generating unit for providing a sequence of signals; wherein each of the impedance elements is a controllable resistor with an adjustable resistance value. The LED light string sequenced in parallel according to claim 9, wherein the LED modules determine the sequence of the LED modules according to the periodic sequence of the sequence signal; the power supply It is a certain voltage source. After completing the sequencing of a light-emitting diode module, 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. . The LED light string sequenced in parallel according to claim 9, wherein the LED modules determine the sequence of the LED modules according to the periodic sequence of the sequence signal; the power supply It is a certain current source. When the sequence 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. . The light-emitting diode light string sequenced in parallel as claimed in claim 9, further comprising: a switch unit connected in series with the controllable resistor. The light-emitting diode light string sequenced in parallel as claimed in claim 1, wherein each of the light-emitting diode modules comprises: a plurality of resistors; and a plurality of switch units, the plurality of resistors are correspondingly connected in series. The light-emitting diode light string sequenced in parallel as described in claim 1, further comprising: A compensation unit is coupled in parallel with the last light-emitting diode module; wherein, the compensation unit includes a controllable resistor whose resistance value can be adjusted. The light-emitting diode light string sequenced in parallel as claimed in claim 14, wherein the power supply is a certain voltage source; when the light-emitting diode modules are sequenced in sequence, the controllable resistance The resistance value decreases sequentially. The LED light string sequenced in parallel as claimed in claim 14, wherein the power supply is a certain current source; when the LED modules are sequenced in sequence, the controllable resistance The resistance value increases sequentially.

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