JP2020079728A - Led current consumption measurement method, led disconnection defect detection method and system using the same - Google Patents

Abstract

To highly accurately measure LED current consumption of a color signal light traffic signal apparatus, and thus to enhance detection accuracy of LED disconnection defects.SOLUTION: An LED current consumption measurement method of the present invention, which is intended for a color signal light traffic signal apparatus 50 that includes a plurality of LEDs 52, a transformer 54 with a gap and a full-wave rectifier 56, is configured to: first calculate an excitation current of the transformer 54 with a gap on the basis of a current instantaneous value of an input AC current to the color signal light traffic signal apparatus 50 in a timing of a zero-crossing input voltage to the color signal light traffic signal apparatus 50, and a sine-wave waveform corresponding to a frequency of the input AC current of which phase is late at 90° from the timing of the zero-crossing input voltage; subtract the excitation current of the transformer 54 with a gap from the input AC current to the color signal light traffic signal apparatus 52; and calculate current consumption of the plurality of LEDs 52. Accordingly, the current consumption of the plurality of LEDs 52 of the color signal light traffic signal apparatus 50 can be highly accurately measured.SELECTED DRAWING: Figure 1

Description

  The present invention is directed to a method for measuring current consumption of an LED, a method for detecting an LED disconnection failure using the same, and an LED disconnection failure detection targeting a colored light traffic signal including a transformer with a gap, a full-wave rectifier, and a plurality of LEDs. It is about the system.

  Lighting of a traffic light targeting a railway, an automobile, an airplane, a person, etc. is an event that must be avoided, and this is the same even in the case of a color light traffic light using an LED, when a disconnection failure of the LED occurs. .. For this reason, in an actual color light traffic light using a plurality of LEDs, the plurality of LEDs are arranged, for example, in the color light traffic light 50 shown in FIG. 5 so that the disconnection failure of one LED does not cause the color light traffic light to be extinguished. It is connected like this. That is, in the color light traffic signal 50 of FIG. 5, the plurality of LEDs 52 constitutes an LED circuit in which the plurality of LEDs 52 connected in series in each column are connected in parallel over the plurality of columns. With such a configuration, even if one LED 52 has a disconnection failure, the LED 52 serially connected to the LED 52 is turned off, and the color light signal device 50 is not turned off. Further, in the color light traffic signal 50 as shown in FIG. 5, it is necessary to monitor the disconnection failure of the LED 52. The conventional method is to measure the input current to the color light traffic light 50 and determine whether or not the current value decreases. The failure detection is performed by the method (for example, refer to Patent Document 1).

JP-A-2000-230959

  Here, in addition to the plurality of LEDs 52, the color lamp traffic light 50 shown in FIG. 5 includes a transformer 54 with a gap that receives an input AC current, a full-wave rectifier 56 that converts the AC current into a DC current, and an LED circuit. And a plurality of resistors 58 installed for each series-connected column of. Therefore, as indicated by an arrow in FIG. 5, the input current to the color light signal device 50 is roughly branched into the current consumed by the plurality of LEDs 52 and the exciting current of the transformer with gap 54. Therefore, even if some of the LEDs 52 have a disconnection failure and the current consumption of the plurality of LEDs 52 decreases, the input current does not exhibit a corresponding decrease in value as shown in the graph of FIG. There is only a slight decrease in current. For reference, FIG. 6 shows the graph positions when 50% of the plurality of LEDs 52 are disconnected. Therefore, the conventional disconnection failure detection method described above, in which the current consumption of the LEDs 52 itself is not grasped, but the input current to the color light signal 50 is measured, detects the disconnection failure of the LEDs 52 from a slight current drop. It is necessary to consider the change of the electric current according to various environments, and it cannot be said to be an effective method.

  The present invention has been made in view of the above problems, and an object of the present invention is to accurately measure the LED current consumption of a color light traffic signal, and further to improve the detection accuracy of an LED disconnection failure. ..

(Aspect of the invention)
The following aspects of the invention exemplify the constitution of the present invention, and are explained separately for each item in order to facilitate understanding of various constitutions of the present invention. Each section does not limit the technical scope of the present invention, while referring to the best mode for carrying out the invention, a part of the constituent elements of each section is replaced, deleted, or further The addition of the constituent elements of (5) is also included in the technical scope of the present invention.

  (1) A plurality of LEDs including a transformer with a gap, a full-wave rectifier that converts an alternating current input via the transformer with a gap into a direct current, and a plurality of LEDs that are turned on by receiving the direct current Is a method for measuring the current consumption of the plurality of LEDs for color light traffic signals connected in series for each of a plurality of rows connected in parallel, the input voltage to the color light traffic light is a method. Based on the instantaneous current value of the input AC current to the colored light traffic light at the timing of zero-crossing, and the sine wave waveform corresponding to the frequency of the input AC current, the phase of which is delayed by 90° from the timing of the zero-crossing of the input voltage. Then, the exciting current of the transformer with the gap is calculated, and the exciting current of the transformer with the gap is subtracted from the input AC current to the color light traffic signal to calculate the consumption current of the plurality of LEDs. Measuring method (claim 1).

  The LED current consumption measuring method described in this item is a transformer with a gap, a full-wave rectifier that converts an alternating current input through the transformer with a gap into a direct current, and a lamp that receives a converted direct current and lights up. The present invention is directed to a color light traffic signal including a plurality of LEDs that operate. In addition, in order to prevent the color light traffic lights from being extinguished due to the disconnection failure of some of the LEDs, the plurality of LEDs of the color light traffic lights are connected to each of a plurality of rows connected in parallel for each arbitrary number of plural LEDs. It is connected in series. In order to measure the current consumption of a plurality of LEDs having such a configuration, the LED current consumption measurement method described in this section is such that the input current to the color light traffic signal is Focusing on branching into the consumed current and the exciting current of the transformer with a gap, first, the exciting current of the transformer with a gap is calculated.

  It is known that the ideal exciting current of a transformer has a phase delay of 90° from the voltage on the primary side. When this is applied to a transformer with a gap of a color light signal, the exciting current of the transformer with a gap is It is considered that the phase is delayed by 90° from the input voltage to the traffic signal. The exciting current of the transformer with a gap exhibits a sine wave having the same cycle as the AC input voltage. Furthermore, the amplitude (peak) of the sine wave is the instantaneous value of the input current to the color light signal at the timing when the secondary side current of the transformer with a gap becomes 0 (in other words, the timing when only the exciting current flows). Required from. Considering that no current flows to the LED on the secondary side of the transformer with a gap until a certain voltage is applied, the timing at which the current on the secondary side of the transformer with a gap becomes 0 is set to the color light signal. It is considered to be the timing when the input voltage crosses zero.

  Therefore, the LED current consumption measurement method described in this section is based on the current instantaneous value of the input AC current to the color light signal and the phase from the timing when the input voltage crosses zero at the timing when the input voltage to the color light signal crosses zero. Based on the sine wave waveform corresponding to the frequency of the input AC current with a delay of 90°, the exciting current of the transformer with a gap is calculated. Further, the exciting current of the transformer with a gap calculated in this way is subtracted from the input AC current to the color light traffic signal to calculate the current consumption of the plurality of LEDs. As a result, the current consumption by the plurality of LEDs of the color light traffic signal can be accurately measured. It should be noted that the current consumption of the plurality of LEDs measured in this way includes the LEDs that are not lit due to the disconnection failure among the plurality of LEDs when a disconnection failure occurs in some of the LEDs. The ratio will be reflected as it is as the reduction ratio.

  (2) In the above item (1), a timing detection step of detecting a timing at which the input voltage to the color light traffic signal crosses zero, and a waveform of an alternating current input to the color light traffic light signal are acquired and converted into digital data. A/D conversion step, a detection result in the timing detection step, and an instantaneous value calculation step of calculating the current instantaneous value based on the conversion data in the A/D conversion step, and detection in the timing detection step. A sine wave calculating step of calculating a sine wave waveform whose phase is delayed by 90° from the zero-cross timing of the input voltage, based on the result and digital data of a sine wave waveform corresponding to the frequency of the input AC current, which is set in advance. And a sine wave waveform whose phase is delayed by 90° from the zero-cross timing of the input voltage, which peaks at the current instantaneous value, based on the calculation result in the instantaneous value calculation step and the calculation result in the sine wave calculation step. Is calculated as an exciting current waveform of the transformer with a gap, based on the exciting current calculating step, the conversion data in the A/D converting step, and the calculating result in the exciting current calculating step, the current consumption of the plurality of LEDs A method of measuring current consumption of an LED, comprising:

  The LED current consumption measuring method described in this section includes various steps for calculating the LED current consumption as described in (1) above, that is, a timing detection step, an A/D conversion step, and an instantaneous value. The calculation process, the sine wave calculation process, the exciting current calculation process, and the consumed current calculation process are included. In the timing detection step, the waveform of the input voltage to the color light signal is acquired, and the timing at which the input voltage crosses zero is detected from the waveform. In the A/D conversion process, the waveform of the alternating current input to the color light traffic signal is acquired and the waveform is converted into digital data. Then, in the instantaneous value calculation step, based on the detection result in the timing detection step and the conversion data in the A/D conversion step, the input AC current to the color light signal at the timing when the input voltage to the color light signal crosses zero. Calculate the current instantaneous value of.

  In the sine wave calculation step, based on the detection result in the timing detection step and the preset digital data of the sine wave waveform corresponding to the frequency of the input alternating current to the color light signal, the zero cross timing of the input voltage is calculated. A sine wave waveform having the same frequency as the input AC current with a phase delayed by 90° is calculated by digital data. Further, in the exciting current calculating step, the exciting current waveform of the transformer with a gap is calculated based on the calculation result in the instantaneous value calculating step and the calculation result in the sine wave calculating step. That is, digital data of a sine wave waveform, which has an amplitude with the current instantaneous value obtained in the instantaneous value calculation step as a peak and is 90° in phase from the zero-cross timing of the input voltage obtained in the sine wave calculation step, is added with a gap. Calculated as the excitation current waveform of the transformer.

  Then, in the consumption current calculation step, the consumption current of the plurality of LEDs is calculated based on the conversion data in the A/D conversion step and the calculation result in the excitation current calculation step. That is, from the digital data of the AC current waveform input to the color light traffic light obtained in the A/D conversion process, the digital data of the excitation current waveform of the transformer with a gap obtained in the excitation current calculation process is subtracted to obtain a plurality of data. The current consumption of the LED is calculated. As a result, only the voltage waveform and the current waveform of the AC power source input to the color light traffic signal are used as input values, and the consumption currents of the plurality of LEDs are calculated from them by digital data. The measurement can be easily and accurately realized.

(3) LED disconnection failure detection for detecting disconnection failure of the plurality of LEDs by using consumption currents of the plurality of LEDs measured by the LED current consumption measurement method according to the above (1) and (2). Method (claim 3).
The LED disconnection failure detection method described in this section uses a plurality of LED consumption currents measured by the LED consumption current measurement methods described in (1) and (2) above to disconnect the plurality of LEDs. Is to detect. That is, as described in (1) above, the current consumption of the plurality of LEDs is lit due to the influence of the disconnection failure among the plurality of LEDs when a disconnection failure occurs in a part of the plurality of LEDs. The ratio of the LEDs that are not reflected is reflected as it is as a reduction rate. By detecting the disconnection failure of a plurality of LEDs by utilizing the current consumption of such LEDs, the disconnection failure of the LED can be detected with high accuracy.

  (4) A plurality of LEDs including a transformer with a gap, a full-wave rectifier that converts an alternating current input via the transformer with a gap into a direct current, and a plurality of LEDs that light up by receiving the direct current. Is a system for detecting a disconnection failure of the plurality of LEDs for a plurality of serially connected color light traffic lights in each of a plurality of columns connected in parallel, wherein the input voltage to the color light traffic lights is A timing detection unit that detects the timing of zero-crossing, an A/D conversion unit that acquires the waveform of the input AC current to the color light signal and converts it into digital data, the detection result by the timing detection unit, and the A An instantaneous value calculation unit that calculates an instantaneous current value of the input AC current to the color light signal at a timing at which the input voltage crosses zero based on the conversion data by the /D conversion unit; and a detection result by the timing detection unit. And a sine wave calculation unit that calculates a sine wave waveform whose phase is delayed by 90° from the zero-cross timing of the input voltage, based on preset digital data of the sine wave waveform corresponding to the frequency of the input AC current. And a sine wave waveform having a phase delayed by 90° from the zero-cross timing of the input voltage, which peaks at the current instantaneous value, based on the calculation result by the instantaneous value calculation unit and the calculation result by the sine wave calculation unit. Is calculated as an excitation current waveform of the transformer with a gap, based on the conversion data by the A/D conversion unit and the calculation result by the excitation current calculation unit, the current consumption of the plurality of LEDs LED disconnection failure detection system including a consumption current calculation unit that calculates a disconnection failure detection unit that detects a disconnection failure of the plurality of LEDs based on a calculation result by the consumption current calculation unit (claim 4). ..

  The LED disconnection failure detection system according to this section is for executing the LED disconnection failure detection method according to (3) above, which utilizes the LED current consumption measurement method according to (2) above. It is a thing. For this reason, the same actions as those of the LED current consumption measuring method and the disconnection failure detecting method of the above (2) and (3) can be obtained.

  Since the present invention has the above-described configuration, it is possible to accurately measure the LED current consumption of the color light traffic signal, and it is possible to improve the detection accuracy of the disconnection failure of the LED.

It is a schematic diagram which shows typically the LED disconnection failure detection system and color light signal device which concern on embodiment of this invention. For the color light signal shown in FIG. 1, there are shown an input voltage waveform to the color light signal and an excitation current waveform of the transformer with a gap when no current is supplied to all LEDs. For the color light traffic light shown in FIG. 1, there are shown an input voltage waveform to the color light traffic light and a current waveform on the secondary side of the transformer with a gap. Regarding the color light signal shown in FIG. 1, (a) shows an input current waveform to the color light signal, (b) shows an exciting current waveform of the transformer with a gap, and (c) shows consumption current waveforms of a plurality of LEDs. .. It is a schematic diagram of the color light traffic light which added the rough flow of the input current. It is a graph which shows the relationship between the input current to a color light signal, and the disconnection rate of the LED circuit of a color light signal.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Throughout the drawings, the same parts or corresponding parts are denoted by the same reference numerals. Further, detailed description of the same or corresponding portions as those of the conventional technique will be omitted.
FIG. 1 shows an embodiment of the present invention for executing an LED current consumption measuring method according to an embodiment of the present invention and an LED disconnection failure detecting method according to an embodiment of the present invention. An example of the configuration of the LED disconnection failure detection system 10 is schematically shown together with the color light signal device 50. The dashed arrows in the figure indicate the flow of data.

  First, the configuration of the color light signal device 50 will be briefly described. The color light signal device 50 is similar to that shown in FIG. 5, in that the transformer 54 with a gap for receiving an input AC current and the AC current is converted into a DC current. It includes a full-wave rectifier 56, a plurality of LEDs 52, and a plurality of resistors 58. The plurality of LEDs 52 form an LED circuit in which a plurality of LEDs 52 connected in series in each column are connected in parallel over a plurality of columns. Further, the plurality of resistors 58 are connected for each series-connected column of LED circuits. The full-wave rectifier 56 does not have to be configured by one element, and may be implemented as a full-wave rectifier circuit.

  Next, as shown in FIG. 1, the LED disconnection failure detection system 10 according to the embodiment of the present invention includes a timing detection unit 12, an A/D conversion unit 14, an instantaneous value calculation unit 16, and a sine wave calculation unit 18. , An excitation current calculation unit 20, a consumption current calculation unit 22, and a disconnection failure detection unit 24. The timing detection unit 12 acquires the waveform of the AC input voltage from the line of the AC power source input to the color light signal device 50. The waveform of the input voltage is a periodic sine wave waveform that alternately oscillates in positive and negative directions, such as the voltage waveforms shown in FIGS. 2 and 3. Then, the timing detection unit 12 detects the zero-cross timing at which the positive/negative of the input voltage is switched from the acquired waveform of the input voltage (timing detection process), and the detection result is used as the instantaneous value calculation unit 16 and the sine wave calculation unit 18. Send to. The timing detection unit 12 as described above is realized by, for example, a photocoupler, an A/D converter, or the like.

The A/D conversion unit 14 acquires a waveform of an AC input current from a line of an AC power source input to the color light traffic signal 50 via a CT sensor (AC current sensor) or the like. Then, the acquired waveform is converted into digital data (A/D conversion step) and output to the instantaneous value calculation unit 16 and the consumption current calculation unit 22. Various A/D converters are used for the A/D conversion unit 14, for example.
The instantaneous value calculation unit 16 uses the timing at which the input voltage is zero-crossed, which is input from the timing detection unit 12, and the digital data of the input current waveform, which is input from the A/D conversion unit 14, to determine the input voltage The current instantaneous value of the input current waveform at the zero-cross timing is calculated with digital data (instantaneous value calculation step). Then, the calculated value is stored and is transmitted to the exciting current calculating unit 20. When there is only a slight difference between the current instantaneous value already stored and the newly calculated current instantaneous value, the current instantaneous value already stored may be used as it is.

  The sine wave calculator 18 stores in advance, as digital data, a sine wave waveform having the same frequency as the frequency of the alternating current input to the color light signal device 50. That is, this sine wave waveform is represented by “sin(2πft)”, where f is the frequency of the alternating current and t is the time. Then, the sine wave calculation unit 18 uses the digital data of the sine wave waveform and the timing at which the input voltage is zero-crossed, which is input from the timing detection unit 12, so as to correspond to the waveform of the current in FIG. 2, for example. The digital data of the sine wave waveform whose phase is delayed by 90° from the timing of zero crossing of the input voltage is calculated (sine wave calculation step). The calculated sine wave waveform is represented by “sin(2πft−π/2)”. After that, the sine wave calculation unit 18 outputs the calculated digital data of the sine wave waveform to the excitation current calculation unit 20.

The exciting current calculation unit 20 receives the instantaneous current value of the input current waveform at the zero-cross timing of the input voltage, which is input from the instantaneous value calculation unit 16, and the digital data of the sine wave waveform, which is input from the sine wave calculation unit 18. By utilizing this, the exciting current of the transformer 54 with a gap is calculated (exciting current calculating step). Specifically, a sine wave waveform whose phase is delayed by 90° from the zero-cross timing, in which the instantaneous current value of the input current waveform at the zero-cross timing is the amplitude (peak), is multiplied by the above two input values to obtain digital data. Calculate with. That is, the sinusoidal waveform when the current instantaneous value of the input current waveform and _{i m,} is represented by _{"i m · sin (2πft-π} / 2) ". Then, the excitation current calculation unit 20 transmits the calculated digital data of the sine wave waveform to the consumption current calculation unit 22.

  The consumption current calculation unit 22 receives the digital data of the input current waveform to the color light signal 50, which is input from the A/D conversion unit 14, and the excitation current of the transformer 54 with a gap, which is input from the excitation current calculation unit 20. The consumption current of the plurality of LEDs 52 is calculated using the digital data of the sine wave waveform shown (consumption current calculation step). Here, FIGS. 4A to 4C respectively show an input current waveform to the color light signal device 50, an excitation current waveform of the transformer 54 with a gap, and a consumption current waveform of the plurality of LEDs 52. That is, the input current waveform to the color light signal device 50 is the sum of the excitation current waveform of the transformer 54 with a gap and the consumption current waveform of the plurality of LEDs 52. Therefore, the current consumption calculation unit 22 subtracts the digital data indicating the excitation current waveform of the transformer 54 with a gap from the digital data indicating the input current waveform to the color light traffic signal 50, thereby reducing the current consumption of the plurality of LEDs 52. Calculate with digital data. After that, the consumption current calculation unit 22 outputs digital data indicating the calculated consumption currents of the plurality of LEDs 52 to the disconnection failure detection unit 24.

The disconnection failure detection unit 24 detects the presence/absence of a disconnection failure of the plurality of LEDs 52 by using the digital data input from the consumption current calculation unit 22 and indicating the current consumption of the plurality of LEDs 52. For example, the disconnection failure detection unit 24 may detect the disconnection failure of the plurality of LEDs 52 by comparing a predetermined threshold value stored in advance with the consumption current values of the plurality of input LEDs 52, or The disconnection failure of the plurality of LEDs 52 may be detected from the temporal change in the current consumption value of the plurality of LEDs 52 input.
The instantaneous value calculation unit 16, the sine wave calculation unit 18, the excitation current calculation unit 20, the consumption current calculation unit 22, and the disconnection failure detection unit 24 all handle digital data. All may be configured by one digital component, or may be configured by a circuit using a plurality of digital components. Further, as long as it can convert the input analog data into digital data and use it, the timing detection unit 12 and the A/D conversion unit 14 may be included in one component.

  By the way, according to the embodiment of the present invention having the above-mentioned configuration, the following operational effects can be obtained. That is, the LED current consumption measuring method according to the embodiment of the present invention converts a transformer 54 with a gap and an alternating current input through the transformer 54 with a gap into a direct current as shown in FIG. It is intended for a color light signal device 50 including a full-wave rectifier 56 and a plurality of LEDs 52 that are turned on by receiving a converted direct current. Further, the plurality of LEDs 52 of the color light traffic signal 50 are arranged in parallel in a plurality of rows so that the color light traffic light 50 does not go out due to the disconnection failure of some of the LEDs 52. The LEDs 52 are connected in series. In order to measure the current consumption of the plurality of LEDs 52 having such a configuration, in the LED current consumption measuring method according to the embodiment of the present invention, the input current to the color light traffic signal 50 is inside the color light traffic light 50. Focusing on branching into the current consumed by the plurality of LEDs 52 and the exciting current of the transformer 54 with gap (see FIGS. 4 and 5), first, the exciting current of the transformer 54 with gap is calculated.

  It is known that the ideal exciting current of the transformer has a phase delay of 90° with respect to the voltage on the primary side. When this is applied to the transformer 54 with a gap of the color light signal device 50, as shown in FIG. It is considered that the exciting current of the attached transformer 54 is delayed in phase by 90° from the input voltage to the color light signal device 50. The exciting current of the transformer 54 with a gap exhibits a sine wave having the same cycle as the AC input voltage. Further, the amplitude (peak) of the sine wave is the input current to the color light signal device 50 at the timing when the current on the secondary side of the transformer with gap 54 becomes 0 (in other words, the timing at which only the exciting current flows). Calculated from the instantaneous value. Here, FIG. 3 shows the waveform of the input voltage (voltage on the primary side of the transformer 54 with a gap) to the color light traffic signal 50 and the waveform of the current on the secondary side of the transformer 54 with a gap. As can be seen in FIG. 3, considering that the LED 52 on the secondary side of the transformer with gap 54 does not flow a current until a certain voltage or more is applied, the current on the secondary side of the transformer with gap 54 becomes smaller. It is considered that the timing when it becomes 0 is the timing when the input voltage to the color light signal device 50 crosses zero.

Therefore, LED current consumption measurement method according to an embodiment of the present invention, at the time when the input voltage to Iroto traffic 50 crosses zero, the current instantaneous value of the input AC current to the Iroto traffic 50 (i _m) , Based on the sinusoidal waveform (sin(2πft−π/2)) corresponding to the frequency of the input AC current, the phase of which is delayed by 90° from the timing of the zero crossing of the input voltage, the exciting current (i _m ·sin(2πft−π/2)) is calculated. Further, the current consumption of the plurality of LEDs 52 is calculated by subtracting the exciting current of the transformer 54 with gap calculated in this way from the input AC current to the color light signal device 50. This makes it possible to accurately measure the current consumption by the plurality of LEDs 52 of the color light signal device 50.

Further, the LED current consumption measuring method according to the embodiment of the present invention includes various steps for calculating the current consumption of the LED 52 as described above, that is, a timing detection step, an A/D conversion step, and an instantaneous value calculation. It includes a process, a sine wave calculating process, an exciting current calculating process, and a consumed current calculating process. FIG. 1 illustrates an LED disconnection failure detection system 10 according to an embodiment of the present invention, which is provided with a plurality of functional units that execute each of these steps. In the timing detection process executed by the timing detection unit 12, the waveform of the input voltage to the color light signal device 50 is acquired, and the timing at which the input voltage crosses zero is detected from the waveform. In the A/D conversion process executed by the A/D conversion unit 14, the waveform of the alternating current input to the color light signal device 50 is acquired and the waveform is converted into digital data. Then, in the instantaneous value calculation step executed by the instantaneous value calculation unit 16, the input voltage to the color light traffic signal 50 crosses zero based on the detection result by the timing detection unit 12 and the conversion data by the A/D conversion unit 14. in the timing, and calculates the current instantaneous value of the input AC current to the Iroto traffic 50 (i _m).

Further, in the sine wave calculation step executed by the sine wave calculation unit 18, the detection result by the timing detection unit 12 and a sine wave waveform (sin(2πft) corresponding to a preset frequency of the input AC current to the color light signal 50 are set. )) based on the digital data, a sine wave waveform (sin(2πft−π/2)) with the same frequency as the input AC current with a phase delay of 90° from the zero cross timing of the input voltage, as shown in FIG. Is calculated with digital data. Further, in the exciting current calculating step executed by the exciting current calculating unit 20, the exciting current waveform of the transformer 54 with a gap is calculated based on the calculation result by the instantaneous value calculating unit 16 and the calculation result by the sine wave calculating unit 18. .. That is, digital data of a sine wave waveform, which has an amplitude with the instantaneous current value obtained by the instantaneous value calculation unit 16 as a peak and is obtained by the sine wave calculation unit 18 and whose phase is delayed by 90° from the zero-cross timing of the input voltage, calculated as an excitation current waveform of the gapped transformer _{54 (i m · sin (2πft} -π / 2)).

  Then, in the current consumption calculation step executed by the current consumption calculation unit 22, the current consumption of the plurality of LEDs 52 is calculated based on the conversion data by the A/D conversion unit 14 and the calculation result by the excitation current calculation unit 20. That is, the digital data of the excitation current waveform of the transformer 54 with a gap, which is obtained by the excitation current calculation unit 20, is subtracted from the digital data of the AC current waveform that is input to the color light signal device 50 that is obtained by the A/D conversion unit 14. Then, the current consumption of the plurality of LEDs 52 is calculated. As a result, since only the voltage waveform and the current waveform of the AC power source input to the color light traffic signal 50 are used as the input values, the consumption currents of the plurality of LEDs 52 can be calculated from the digital values, and thus the plurality of LEDs 52 can be calculated. It becomes possible to easily and accurately measure the consumption current.

  Furthermore, the LED disconnection failure detection method according to the embodiment of the present invention utilizes the consumption currents of the plurality of LEDs 52 measured by the above-described LED consumption current measurement method, for example, the disconnection failure detection unit shown in FIG. The disconnection failure of the plurality of LEDs 52 is detected by 24. That is, in the current consumption of the plurality of LEDs 52 measured as described above, when the disconnection failure occurs in a part of the plurality of LEDs 52, among the plurality of LEDs 52, the LED 52 that is not lit due to the influence of the disconnection failure. The ratio is reflected as it is as a reduction ratio. By detecting the disconnection failure of the plurality of LEDs 52 by utilizing the current consumption of the LED 52 as described above, it becomes possible to detect the disconnection failure of the LED 52 with high accuracy.

On the other hand, the LED disconnection failure detection system 10 according to the embodiment of the present invention uses the LED current consumption measurement method according to the embodiment of the present invention to detect the LED disconnection failure. It is for carrying out the method. Therefore, it is possible to achieve the same operational effect corresponding to the LED current consumption measuring method and the disconnection failure detecting method according to the embodiment of the present invention.
In the LED current consumption measuring method and the disconnection failure detecting method according to the embodiment of the present invention, the instantaneous current value of the input AC current to the color light traffic signal 50 at the timing when the input voltage to the color light traffic light 50 crosses zero. And a sine wave waveform corresponding to the frequency of the input AC current, which is delayed by 90° in phase from the timing at which the input voltage crosses zero, and the exciting current of the transformer 54 with a gap is calculated. If the current consumption of the plurality of LEDs 52 is calculated by subtracting it from the input AC current to the color light traffic signal 50, even if the configuration is different from that of the LED disconnection failure detection system 10 shown in FIG. Good.

  10: LED disconnection failure detection system, 12: Timing detection unit, 14: A/D conversion unit, 16: Instantaneous value calculation unit, 18: Sine wave calculation unit, 20: Excitation current calculation unit, 22: Current consumption calculation unit , 24: disconnection failure detection unit, 50: color light signal, 52: LED, 54: transformer with gap, 56: full-wave rectifier

Claims (4)

A transformer with a gap, a full-wave rectifier that converts an alternating current input via the transformer with a gap into a direct current, and a plurality of LEDs that are turned on by receiving the direct current, and the plurality of LEDs are connected in parallel. A method for measuring the current consumption of the plurality of LEDs for color light traffic signals connected in series for each of a plurality of connected rows, comprising:
The frequency of the input AC current, in which the phase is delayed by 90° from the current instantaneous value of the input AC current to the color light signal and the timing at which the input voltage crosses zero, at the timing when the input voltage to the color light signal crosses zero. Based on the sine wave waveform corresponding to, calculate the exciting current of the transformer with a gap,
A method of measuring current consumption of an LED, wherein current consumption of the plurality of LEDs is calculated by subtracting an exciting current of the transformer with a gap from an input AC current to the traffic light signal. A timing detection step of detecting the timing at which the input voltage to the color light signal crosses zero,
An A/D conversion step of acquiring the waveform of the input alternating current to the color light signal and converting it into digital data;
An instantaneous value calculation step of calculating the current instantaneous value based on the detection result of the timing detection step and the conversion data of the A/D conversion step;
Based on the detection result in the timing detection step and the preset digital data of the sine wave waveform corresponding to the frequency of the input AC current, a sine wave waveform whose phase is delayed by 90° from the zero cross timing of the input voltage is generated. A sine wave calculation step for calculating,
Based on the calculation result in the instantaneous value calculation step and the calculation result in the sine wave calculation step, a sine wave waveform whose phase is delayed by 90° from the zero-cross timing of the input voltage, which peaks at the current instantaneous value, An exciting current calculation step of calculating as an exciting current waveform of the transformer with a gap,
2. A current consumption calculation step of calculating current consumption of the plurality of LEDs based on conversion data in the A/D conversion step and a calculation result in the excitation current calculation step. A method for measuring current consumption of an LED as described.   A method for detecting a disconnection failure of an LED, wherein a disconnection failure of the plurality of LEDs is detected by utilizing the consumption currents of the plurality of LEDs measured by the method of measuring the consumption current of the LED according to claim 1. .. A transformer with a gap, a full-wave rectifier that converts an alternating current input via the transformer with a gap into a direct current, and a plurality of LEDs that are turned on by receiving the direct current, and the plurality of LEDs are connected in parallel. A system for detecting a disconnection failure of the plurality of LEDs for a color light traffic signal connected in series for each of a plurality of connected rows,
A timing detection unit for detecting the timing at which the input voltage to the color light signal crosses zero,
An A/D conversion unit that acquires the waveform of the input AC current to the color light signal and converts it into digital data;
An instantaneous value for calculating the current instantaneous value of the input alternating current to the color light signal at the timing when the input voltage crosses zero based on the detection result by the timing detection unit and the conversion data by the A/D conversion unit. A calculator,
A sine wave waveform whose phase is delayed by 90° from the zero-cross timing of the input voltage based on the detection result by the timing detection unit and preset digital data of the sine wave waveform corresponding to the frequency of the input AC current. A sine wave calculation unit that calculates
Based on the calculation result by the instantaneous value calculation unit and the calculation result by the sine wave calculation unit, a sine wave waveform whose phase is delayed by 90° from the zero-cross timing of the input voltage, which peaks at the current instantaneous value, An exciting current calculation unit that calculates the exciting current waveform of the transformer with a gap,
A current consumption calculating unit that calculates current consumption of the plurality of LEDs based on the conversion data by the A/D conversion unit and the calculation result by the excitation current calculating unit;
A disconnection failure detection system for an LED, comprising: a disconnection failure detection section that detects a disconnection failure of the plurality of LEDs based on a calculation result by the consumption current calculation section.

Images