JP2010165505A - Monitoring circuit and illumination drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring circuit of lamp life capable of reducing manufacturing costs. <P>SOLUTION: The monitoring circuit includes a memory for recording accumulated time showing lighting time of a light-emitting device and operating time of an output control unit while specified time is recorded in advance on the basis of life of the light-emitting device or the output control unit, a timer starting time measurement from accumulated time read out from the memory on the basis of starting of power supply and periodically updating measuring time as accumulated time and updating the measuring time as accumulated time when there are instructions for recording of measuring time, a comparator for comparing the specified time and the accumulated time and transmitting a report signal to the output control unit in order to report that the measuring time reaches to the specified time when both time is coincided, a voltage detection unit for supplying power to a timer, the memory, and the comparator while the light-emitting device is lighted up and instructing recording of the measuring time to the timer when applied voltage becomes a threshold or below, and an auxiliary power supply element for supplying power to the timer when power supply is stopped from the voltage detection unit to the timer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a monitoring circuit and an illumination driving device for monitoring the life of a lamp.

  Lighting device lamps have a lifetime. At the end of the life, which is near the end of the service life, a phenomenon occurs in which the electrode portion of the lamp becomes hot and the socket portion may be thermally deformed. Moreover, the power supply circuit element of the illumination driving device for supplying power to the lamp also has a lifetime. When the illumination driving device is used for a certain period or more, an electrolytic capacitor which is a kind of power circuit element may be deteriorated.

  The above problems can be avoided by replacing the lamp or power circuit element before the end of its life. There is known a method in which a processor such as a general-purpose microcomputer is mounted on an illumination driving device, the processor manages the lamp lighting time, and notifies the user of the lamp replacement time (see Patent Document 1).

JP 2005-222960 A

  Since the method disclosed in Patent Document 1 requires a general-purpose microcomputer with a high unit price as a component, there is a problem that the price of the illumination driving device is increased.

  The present invention has been made to solve the above-described problems of the technology, and an object of the present invention is to provide a monitoring circuit and an illumination driving device for monitoring the lamp life with reduced manufacturing costs.

In order to achieve the above object, the monitoring circuit of the present invention comprises:
A memory for recording a predetermined time based on a lifetime of a light emitting device or an output control unit that supplies power to the light emitting device, and recording an accumulated time indicating a lighting time of the light emitting device or an operation time of the output control unit When,
When power supply is started, time measurement starts from the accumulated time read from the memory, the measurement time is periodically updated as the accumulated time, and if there is an instruction to record the measurement time, A timer for updating time as the cumulative time;
Comparing the specified time and the accumulated time, and when these times match, a comparator that sends a notification signal for notifying that the specified time has been reached to the output control unit;
A voltage detector for supplying power to the timer, the memory and the comparator while the light emitting device is lit, and instructing the timer to record a measurement time when an externally applied voltage falls below a threshold; ,
When power supply from the voltage detection unit to the timer is stopped, an auxiliary power supply element that supplies power to the timer;
It is the structure which has.

  According to the present invention, since a general-purpose microcomputer with a high unit cost is not required, the manufacturing cost can be reduced.

It is a figure which shows one structural example at the time of connecting the illumination drive device of this embodiment to the light emitting device. FIG. 2 is a block diagram illustrating a configuration example of a timer IC illustrated in FIG. 1. FIG. 2 is a block diagram illustrating a configuration example of an output control unit illustrated in FIG. 1. It is a flowchart which shows the operation | movement procedure of the timer IC in this embodiment. It is a block diagram which shows another structural example of the timer IC in this embodiment.

  A configuration of the illumination driving device of the present embodiment will be described. FIG. 1 shows an example of the configuration when the illumination driving apparatus of the present embodiment is connected to a light emitting device.

  As shown in FIG. 1, the illumination driving device 1 is connected to the light emitting device 3 through a power supply line 21. The illumination driving apparatus 1 includes an output control unit 4 that supplies power to the light emitting device 3 and a timer IC (Integrated Circuit) 2 that records the lighting time of the light emitting device 3. The output control unit 4 and the timer IC 2 are connected by a power supply line 22 and a signal line 23. The light emitting device 3 is, for example, a light emitting element such as a fluorescent lamp, a light emitting diode, or an electroluminescence panel. In the present embodiment, it is assumed that the lifetimes of the power supply circuit elements of the light emitting device 3 and the output control unit 4 are the same. The timer IC is an example of the monitoring circuit of the present invention.

  FIG. 2 is a block diagram showing a configuration example of the timer IC shown in FIG. The timer IC 2 includes a voltage detection unit 8, a memory 7, a comparator 9, and a timer 10. The voltage detection unit 8 is connected to the output control unit 4 through a power supply line 22 and is connected to the timer 10 through a signal line. The timer 10 is connected to the memory 7 through a signal line. In the comparator 9, each of two input terminals is connected to the memory 7 via a signal line, and an output terminal is connected to the output control unit 4 via a signal line 23.

  Power is supplied from the output control unit 4 to the timer IC 2 via the power supply line 22. A terminal provided in the voltage detection unit 8 and connected to the power supply line 22 corresponds to a power input terminal of the timer IC 2. In addition, an operating voltage is supplied from the voltage detection unit 8 to each of the memory 7, the comparator 9, and the timer 10 via wiring not shown in the drawing.

  The memory 7 has an accumulated time recording area 5 for recording the time measured by the timer 10 and a specified time recording area 6 for recording a predetermined specified time. The specified time is determined based on the lifetime of the light emitting device 3 and the power supply circuit element, and is normally set to a time shorter than the time when the light emitting device 3 or the power supply circuit element reaches the lifetime. A terminal 27 for inputting a reset signal for the purpose of erasing data recorded in the accumulated time recording area 5 is provided in the memory 7. The memory 7 is a non-volatile memory such as an EEPROM (Electrically Erasable and Programmable ROM).

  A capacitor is connected to the timer 10 as the auxiliary power element 12. When the timer 10 receives a recording instruction signal that is an instruction to record the measurement time from the voltage detector 8, the timer 10 records the measurement time in the accumulated time recording area 5. When the operating voltage supplied to the timer 10 drops, the auxiliary power supply element 12 supplies the timer 10 with the minimum power necessary for recording the measurement time in the memory 7. Charge is accumulated in the auxiliary power supply element 12 when an operating voltage is applied from the voltage detection unit 8 to the timer 10. In addition, when the voltage applied from the voltage detector 8 becomes 0 V or higher, the timer 10 reads information on the accumulated time from the accumulated time recording area 5 and starts measuring time from the accumulated time. Then, the measurement time recorded in the accumulated time recording area 5 is periodically updated.

  The voltage detection unit 8 monitors the voltage applied from the output control unit 4, and when the voltage falls below a threshold value, in order to cause the timer 10 to record the measurement time in the accumulated time recording area 5, the recording instruction signal is sent to the timer 10. Send to. This threshold value is lower than the voltage applied from the output control unit 4 when the light emitting device 3 is lit in the normal state, but is preferably larger than the operating voltage of the timer 10.

  The comparator 9 compares the accumulated time recorded in the accumulated time recording area 5 with the specified time recorded in the specified time recording area 6. If the accumulated time does not match the specified time, a first signal that is a signal having a predetermined voltage level is output. If the accumulated time matches the specified time, a signal having a level different from the specified voltage level is output. The second signal is output. This second signal is a notification signal for notifying that the specified time has been reached. For example, when the first signal is set to the high level, the second signal is set to the low level. On the other hand, when the first signal is at a low level, the second signal is at a high level. In the following description, the first signal is set to the high level and the second signal is set to the low level.

  Next, the configuration of the output control unit 4 will be described. FIG. 3 is a block diagram illustrating a configuration example of the output control unit illustrated in FIG. As shown in FIG. 3, the output control unit 4 includes a power supply circuit element 35, a protection circuit 31, a signal processing circuit 32, and a warning processing unit 33.

  The protection circuit 31 supplies power input via the power supply line 26 to the light emitting device 3 and the timer IC 2. When the power supply voltage applied via the power supply line 26 deviates from a predetermined range, the power supply to the light emitting device 3 and the timer IC 2 is stopped. Thereby, it is possible to prevent the light emitting device 3 and the timer IC 2 from being destroyed due to the abnormal voltage value.

  The power circuit element 35 stabilizes the voltage applied from the protection circuit 31 and supplies it to the light emitting device 3. When the electricity input via the power supply line 26 is alternating current and the timer IC 2 is direct current driven, it is assumed that the protection circuit 31 is provided with an alternating current-direct current conversion circuit.

  When the signal received from the timer IC 2 via the signal line 23 changes from the high level to the low level, the signal processing circuit 32 transmits a control signal to the warning processing unit 33.

  The warning processing unit 33 is for notifying the user that the light emitting device 3 or the output control unit 4 has reached the end of its life. The warning processing unit 33 is a warning lamp light emitting unit or a warning sound output unit. The warning lamp is an LED or a light bulb. The warning sound output unit is an audio IC. When the warning processing unit 33 is a warning lamp light emitting unit, the warning processing unit 33 turns on the warning lamp when receiving a control signal from the signal processing circuit 32. When the warning processing unit 33 is a warning sound output unit, the warning processing unit 33 sounds a warning sound when receiving a control signal from the signal processing circuit 32.

  Next, the operation of the timer IC 2 in the illumination driving device of the present embodiment will be described. FIG. 4 is a flowchart showing the operation procedure of the timer IC of the present embodiment.

  When the user turns on the power of the proof drive device 1, the light emitting device 3 is turned on, and the timer IC 2 reads the accumulated time from the accumulated time recording area 5, and starts time measurement following the accumulated time (step 101). . Subsequently, it is determined whether or not the voltage applied from the output control unit 4 is greater than a threshold value (step 102). If the applied voltage is greater than the threshold value, time measurement is continued (step 103). Then, it is determined whether or not the accumulated time and the specified time match (step 104). If the accumulated time and the specified time match, the level of the output signal of the comparator 9 is changed and the warning processing unit 33 is informed in advance. The process is executed (step 105). The warning processing unit 33 performs processing such as turning on a warning lamp or outputting a warning sound. If the accumulated time does not match the specified time in step 104, the process returns to step 102.

  When the voltage applied to the timer IC2 becomes equal to or lower than the threshold value in step 102, the timer IC2 records the measurement time in the accumulated time recording area 5 (step 106). The operation at this time will be described in detail. When the voltage applied to the timer IC2 becomes equal to or lower than the threshold value, the timer IC2 shifts to the recording mode for the cumulative time recording area 5. At this time, the supply of power from the auxiliary power supply element 12 connected to the timer 10 prevents the voltage applied to the timer 10 from instantaneously becoming 0, and the applied voltage drops gently. Further, the auxiliary power supply element 12 suppresses the voltage applied to the timer 10 from becoming smaller than the operating voltage while the timer 10 is recording in the cumulative time recording area 5.

  When the warning lamp is turned on or a warning sound is output based on the processing in step 105, the user replaces the light emitting device 3 and the power supply circuit element 35 with new ones. , The data recorded in the accumulated time recording area 5 is erased.

  The signal processing circuit 32 and the protection circuit 31 may be connected by a signal line. When the signal received from the timer IC 2 via the signal line 23 changes from the high level to the low level, the signal processing circuit 32 forcibly stops the power supply to the light emitting device 3 from the protection circuit 31. With this configuration, the warning processing unit 33 may not be provided.

  In the above embodiment, the case where the lifetimes of the light emitting device 3 and the power supply circuit element 35 are the same has been described. However, these lifetimes may not be the same. FIG. 5 is a block diagram showing another configuration example of the timer IC in this embodiment. The same components as those illustrated in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the memory 7 of the timer IC 25 shown in FIG. 5, a specified time recording area 6a in which a specified time based on the lifetime of the light emitting device 3 is registered, and an accumulated time for recording the accumulated time corresponding to the lighting time of the light emitting device 3. A recording area 5a is provided. Further, in the memory 7, a specified time recording area 6 b in which a specified time based on the life of the power supply circuit element 35 is registered, and an accumulated time recording area 5 b for recording the accumulated time corresponding to the operation time of the output control unit 4. Is provided.

  The terminal 27a is for erasing data recorded in the accumulated time recording area 5a, and the terminal 27b is for erasing data recorded in the accumulated time recording area 5b. Since the terminal for inputting the reset signal is provided separately, the accumulated time can be individually reset even if the replacement timing of the light emitting device 3 and the power supply circuit element 35 is different.

  Further, as shown in FIG. 5, two comparators 9 a and 9 b are provided in the timer IC 25. The comparator 9a compares the specified time registered in the specified time recording area 6a and the accumulated time recorded in the accumulated time recording area 5a, and if these times match, the specified time based on the lifetime of the light emitting device 3 is reached. A notification signal for notifying that it has been sent is transmitted to the output control unit 4. The comparator 9b compares the specified time registered in the specified time recording area 6b and the accumulated time recorded in the accumulated time recording area 5b. If these times match, the comparator 9b sets the specified time based on the lifetime of the power supply circuit element 35. A notification signal for notifying that it has been reached is transmitted to the output control unit 4.

  The output control unit 4 causes the warning processing unit 33 to execute when a notification signal is received from the comparator 9a via the signal line 23a and when a communication signal is received from the comparator 9b via the signal line 23b. Or may be the same. If the warning processing unit 33 changes the type of warning processing depending on the comparison of the notification signal transmission sources 9a and 9b, the user can determine whether the light emitting device 3 is nearing the end of its life from the content of the processing. It can be seen that the power supply circuit element 35 is.

  Also in this case, the signal processing circuit 32 may cause the protection circuit 31 to stop supplying power to the light emitting device 3 upon receiving any notification signal instead of operating the warning processing unit 33.

  Here, the case where one timer IC 2 is used as a method for separately monitoring the lifetimes of the light-emitting device 3 and the power supply circuit element 35 has been described. A dedicated timer IC or a power supply circuit element dedicated timer IC may be used.

  In the monitoring circuit of the present embodiment, a power input terminal provided in the voltage detector 8, a ground potential terminal (not shown), an output terminal of the comparator 9, and a terminal 27 for inputting a reset signal. There should be at least terminals. The number of terminals is about 2/3 to 1/2 of the general-purpose microcomputer.

  In the illumination driving apparatus of the present embodiment, the manufacturing cost can be reduced by using a dedicated monitoring circuit (corresponding to the timer IC) specialized for time accumulation calculation without using a general-purpose microcomputer. Then, by reducing the number of IC pins mounted on the circuit board of the illumination driving device 1, it is possible to simultaneously achieve downsizing and space saving of the circuit board. In the above-described embodiment, the lifetimes of both the light emitting device 3 and the power supply circuit element 35 are monitored, but either one may be used.

1 Illumination drive device 2 Timer IC
DESCRIPTION OF SYMBOLS 3 Light emitting device 4 Output control part 5 Cumulative time recording area 6 Specified time recording area 7 Memory 8 Voltage detection part 9 Comparator 10 Timer 12 Auxiliary power supply element 31 Protection circuit 32 Signal processing circuit 33 Warning processing part 35 Power supply circuit element

Claims (4)

A memory for recording a predetermined time based on a lifetime of a light emitting device or an output control unit that supplies power to the light emitting device, and recording an accumulated time indicating a lighting time of the light emitting device or an operation time of the output control unit When,
When power supply is started, time measurement starts from the accumulated time read from the memory, the measurement time is periodically updated as the accumulated time, and if there is an instruction to record the measurement time, A timer for updating time as the cumulative time;
Comparing the specified time and the accumulated time, and when these times match, a comparator that sends a notification signal for notifying that the specified time has been reached to the output control unit;
A voltage detector for supplying power to the timer, the memory and the comparator while the light emitting device is lit, and instructing the timer to record a measurement time when an externally applied voltage falls below a threshold; ,
When power supply from the voltage detection unit to the timer is stopped, an auxiliary power supply element that supplies power to the timer;
Having a monitoring circuit. In the memory, a first specified time that is the specified time based on the lifetime of the light emitting device and a second specified time that is the specified time based on the lifetime of the output control unit are registered in advance,
The timer records, in the memory, a first cumulative time that is the cumulative time corresponding to the lighting time of the light emitting device, and a second cumulative time that is the cumulative time corresponding to the operation time of the output control unit. In the memory,
The comparator is
The first specified time and the first accumulated time are compared, and when these times match, a notification signal for notifying that the first specified time has been reached is transmitted to the output control unit. One comparator,
The second specified time and the second accumulated time are compared, and when these times match, a notification signal for notifying that the second specified time has been reached is transmitted to the output control unit. The monitoring circuit according to claim 1, comprising two comparators. The monitoring circuit according to claim 1 or 2, and the output control unit,
The output control unit
When a control signal is received, a warning processing unit that turns on a warning lamp or outputs a warning sound,
And a signal processing circuit that transmits the control signal to the warning processing unit when the notification signal is received from the comparator. The monitoring circuit according to claim 1 or 2, and the output control unit,
The output control unit
A protection circuit for stopping power supply to the light emitting device upon receipt of the control signal;
And a signal processing circuit that transmits the control signal to the protection circuit when the notification signal is received from the comparator.

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