JP3824139B2 - lighting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a luminaire including a microcomputer (control circuit) that receives a pulse-like synchronization signal synchronized with an AC power supply, generates a phase control signal from the synchronization signal, and controls the phase of a lamp.
[0002]
[Prior art]
In a lighting fixture provided with a microcomputer (control circuit) that receives a pulse-shaped synchronization signal synchronized with an AC power supply, generates a phase control signal from the synchronization signal, and controls the phase of the lamp, When the synchronization signal is a positive pulse, a level is determined after a predetermined time from the starting point which is a rising edge, for example, 10 μs later, and it is determined whether or not the synchronization signal is handled as a true synchronization signal. If the level is high, the synchronization signal is treated as a true synchronization signal.
[0003]
[Problems to be solved by the invention]
However, when high-level pulse noise (usually a very short time that does not reach 10 μs) is mixed in a long section where the synchronization signal is at a low level, it can be determined that the noise is different from the synchronization signal, but the probability is small. When a low level pulse noise is mixed in a section in which the synchronization signal is at a high level (eg, about 500 to 1000 μs), a rising edge occurs at the end of the noise, and the probability that the level after 10 μs is also at a high level Therefore, this is handled as a synchronization signal, which causes a malfunction in which a phase control signal is generated with the edge as a true starting point, causing a problem such as a lamp flickering. In view of such a problem to be solved, an object of the present invention is to provide a lighting apparatus capable of accurately determining a synchronization signal.
[0004]
[Means for Solving the Problems]
The present invention provides a lighting apparatus including a control circuit that receives a pulse-shaped synchronization signal synchronized with an AC power supply, generates a phase control signal using the synchronization signal as a starting point, and controls the phase of the lamp. Only when the level determination of the synchronization signal line is performed every predetermined period, and the level after a predetermined time from the starting point of the synchronization signal is different from the level immediately before the starting point among the levels sampled every fixed period, It is a luminaire that regards the synchronization signal as a true synchronization signal.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described. However, this is merely an exemplary embodiment adopted based on the present invention, and the present invention should not be limitedly interpreted based on matters specific to the embodiment. Rather, the technical scope of the present invention should be determined based on the matters shown in the claims and matters substantially equivalent thereto.
[0006]
The illustrated embodiment includes a microcomputer (control circuit) 3 that receives a pulsed synchronization signal synchronized with the AC power supply 1, generates a phase control signal starting from the synchronization signal, and controls the phase of the lamp 2. It is a lighting fixture. A synchronizing signal generating circuit 4 and a DC power source 5 are connected to the AC power source 1, a synchronizing signal generated at the output of the synchronizing signal generating circuit 4 is input to the microcomputer 3, and the DC power source 5 is connected to the synchronizing signal generating circuit 4 and the microcomputer 3. Power is being supplied. The microcomputer 3 is a one-chip type incorporating a CPU, ROM, RAM, watchdog timer, timer, and the like. The phase control signal output from the microcomputer 3 controls the phase of the lamp 2 via a phase control element 6 such as a triac. As the phase control signal, a trigger pulse signal generated after a desired time from the starting point of the synchronizing signal, or a high or low level generated after a desired time from the starting point of the synchronizing signal and finished at the zero cross point of the AC power supply 1 is used. These signals are used to turn on the phase control element 6, and the dimming level of the lamp 2 is determined corresponding to the ON section.
[0007]
The microcomputer 3 determines the level of the synchronization signal line at a constant cycle of, for example, 200 μs. At the same time, the microcomputer 3 compares the level at the time t3 after a predetermined time (for example, 10 μs) from the starting point t2 of the synchronizing signal (determined by the rising edge of the synchronizing signal) and the level sampled at a constant period of 200 μs. Only when the level at time t1 immediately before the starting point t2 is different, the synchronization signal is regarded as a true synchronization signal. The illustrated example shows a case where the starting point of the synchronizing signal is a rising signal, and the level at time t3 is H, and the level at time t1 is L, so they are regarded as true synchronizing signals. Further, in the case where the synchronization signal is an inverted signal, the level at time t3 is L, and the level at time t1 is H, so that they are regarded as true synchronization signals if they are different from each other.
[0008]
Referring also to the determination flow of FIG. 2, when an edge is detected at time t2, the level is determined after 10 μs has elapsed, that is, at time t3. If it is L, it is determined that it is not a synchronization signal. That is, in a long low level section where there is no synchronization signal, the noise superimposed on the AC power supply 1 that often does not reach 10 μs is not mistaken for the synchronization signal. However, if the level at time t3 is H, the level immediately before edge detection (time t1) is determined. If it is H, it is determined not to be a synchronization signal, and if it is L, it is determined to be a synchronization signal. Even when the synchronizing signal is inverted from FIG. 1B, if an edge is detected at time t2, the level is determined at time t3 after 10 μs has elapsed. If it is H, it is determined that it is not a synchronization signal. However, if it is L, the level immediately before the edge detection (time t1) is determined. If it is L, it is determined not to be a synchronization signal, and if it is H, it is determined to be a synchronization signal.
[0009]
According to the present embodiment, when low level pulse noise is mixed in a section where the synchronization signal is at a high level (for example, about 500 to 1000 μs), the level 10 μs after the rising start point at the end of the noise is H, Since the fixed period sampling level just before the starting point is H, both are the same, so that the rising signal after mixing the low level pulse noise has the accuracy of not judging it as a true sync signal, and after the low level pulse noise is mixed The phase control signal is not generated after a desired time from the starting point of the rising signal. Further, as is clear from the above description, the determination of the synchronization signal is similarly accurate even if the synchronization signal is the falling start point.
[Brief description of the drawings]
1A is a circuit block diagram showing an embodiment of the present invention, FIG. 1B is a waveform diagram of the synchronization signal, and FIG. 2 is a flowchart showing the determination operation.
1 AC power supply 2 Lamp 3 Microcomputer (control circuit)
4 Sync signal generator

Claims (1)

In a luminaire provided with a control circuit that receives a pulse-shaped synchronization signal synchronized with an AC power supply, generates a phase control signal based on the synchronization signal, and controls the phase of the lamp, the control circuit includes the synchronization signal line Is determined at regular intervals, and only when the level after a predetermined time from the starting point of the synchronization signal is different from the level immediately before the starting point among the levels sampled at regular intervals. Lighting fixtures that are considered as sync signals.

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