JP4108143B2 - Dimmable lighting device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a dimming illumination device having a dimming degree according to a duty ratio of a rectangular wave signal .
[0002]
[Prior art]
Conventionally, a dimming method using a change in duty ratio of a rectangular wave as a dedicated dimming signal has been widely used. An example of the dimming signal is a rectangular wave having a frequency of 1 kHz (period 1 ms). If the duty ratio is 75%, the lighting load is turned on with a brightness of 75%. Illumination loads include incandescent lamps, fluorescent lamps, high pressure discharge lamps, and the like. In general, the dimming signal line and the power supply line are often sent to many lighting loads and wired.
[0003]
[Problems to be solved by the invention]
The above prior art has the following problems. As described above, there are incandescent lamps, fluorescent lamps, high-pressure discharge lamps, etc. as lighting loads, but the main dimming methods are phase control method, dimming method by high frequency lighting, dimming by low frequency rectangular wave lighting. It is a method. Among them, in the low frequency rectangular wave system that is frequently used for lighting a high pressure discharge lamp or a fluorescent lamp, a rectangular wave similar to a dedicated dimming signal is used, so that malfunction due to mutual interference is likely to occur. For example, when the rectangular wave lighting frequency is set to 200 Hz with respect to the 1 kHz rectangular wave dedicated dimming signal, both are not synchronized frequencies, so the low frequency rectangular wave lighting frequency with high power causes the rectangular wave dedicated dimming signal to There is a possibility that noise is mixed in the frequency and the dimming signal cannot be received accurately. In addition, when multiple lighting loads are connected on the same wiring, due to variations in the respective lighting frequencies, a component of the frequency deviation occurs, which becomes noise and makes it difficult to receive the dedicated dimming signal. There is a risk.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the waveform of a rectangular wave signal dedicated to dimming is set as a main waveform, and the main waveform is divided to form a sub waveform, and the illumination load is turned on by the sub waveform.
[0005]
[Action]
Since the lighting waveform is generated from a rectangular wave signal dedicated to dimming, the lighting waveform and the rectangular wave signal waveform are always synchronized. Therefore, even in the case of a single illumination load as well as in the case of a plurality of illumination loads, there is no generation of unnecessary noise in the duty ratio detection unit that operates synchronously and determines the dimming degree , and the dimming signal is accurately generated. Can receive.
[0006]
【Example】
The device of the present invention shown in FIGS. 1 to 3 will be described. FIG. 1 is a system diagram of a dimming illumination device. FIG. 2 is a circuit diagram thereof. FIG. 3 is a signal waveform diagram thereof. The illustrated lighting control device includes a power line 101 wired from a commercial AC power source 5. A dimming signal line 102 wired from a rectangular wave signal transmitter 6 that forms a rectangular wave signal (dimming signal) with a variable duty ratio and a constant frequency is provided. Dimming devices 1A and 1B connected to the power supply line 101 and the dimming signal line 102 are provided. A circuit diagram of the light control device 1A of FIG. 1 is as shown in FIG. A circuit diagram of another dimmer 1B of FIG. 1 is also as shown in FIG. The lighting load 3 (3A or 3B in FIG. 1) of the light control device 1 (1A or 1B in FIG. 1) is set to a dimming degree according to the duty ratio.
[0007]
The dimmer 1 receives a rectifier circuit 15 that rectifies a commercial AC power supply 5 voltage, a chopper circuit 80 at a subsequent stage, an inverter circuit 90 that converts a DC output voltage of the chopper circuit 80 into an AC rectangular wave voltage, and the AC rectangular wave voltage. The lighting load 3 is provided. The components of the chopper circuit 80 are a chopper transistor 14, a chopper inductor 16, a reverse blocking diode 17, a smoothing capacitor 18, and the like. The main components of the inverter circuit 90 are switching transistors 9, 10, 11, and 12 that form a bridge circuit.
[0008]
Further, the dimming device 1 receives the rectangular wave signal and forms a relatively low frequency sub-waveform having a value obtained by dividing the frequency by an integer, and an inverter circuit so that the operating frequency is equal to the sub-waveform. A lighting control circuit 8 for controlling 90 and lighting the lighting load 3 is provided.
[0009]
The light control device 1 of FIG. 2 operates as follows. The commercial AC power supply 5 voltage input from the power supply line 101 is DC converted by the rectifier circuit 15. The output corresponding to the load power of the illumination load 3 is produced by the step-down chopper circuit 80 at the subsequent stage. The voltage across the smoothing capacitor 18 becomes the DC output voltage of the chopper circuit 80. The DC output voltage is alternately inverted by a full bridge type inverter circuit 90, converted to AC, and supplied to the lighting load 3.
[0010]
Accordingly, the illumination load 3 is turned on by rectangular wave power having a frequency corresponding to the operating frequency of the inverter circuit 90 . This operating frequency is generated by inputting a lighting signal obtained by converting a rectangular wave signal from a rectangular wave signal generator (dimming controller) 6 having a variable duty ratio by a frequency dividing circuit 7 to a lighting control circuit 8.
[0011]
FIG. 3 shows the state of conversion and formation of the lighting operation frequency. Has become a rectangular wave signal (dimming signal) of 6 divided by six cycles corresponds to one period of the lighting signal divider circuit 7 in case of FIG. For example, when the rectangular wave signal (dimming signal) and 1 kHz, the lighting signal is 1 166.7Hz of six minutes. Generally, when performing rectangular wave lighting, avoid the occurrence of the re-ignition voltage of the lighting load 3 columns, and in order to reduce the loss of the transistor 9, 10, 11, 12 for reversing, 500 Hz approximately from 50Hz Is often selected. Therefore, if the rectangular wave signal (dimming signal) is 1 kHz, 1/2 (= 500 Hz), 1/3 (= 333 Hz), 1/4 (= 250 Hz), 1/5 (= 200 Hz), 1 / It is possible to select frequencies up to 1/20 such as 6 (= 166.7 Hz), 1/7 (= 143 Hz), 1/8 (= 125 Hz), 1/10 (= 100 Hz), etc. . In this way, when the lighting load 3 is turned on by mutually synchronized signals, no noise is generated from the lighting load 3 in the duty ratio part (arrow part) of the dimming signal shown in FIG. Can be reliably detected. Further, as shown in FIG. 1, when there are two illumination loads 3A and 3B , and even when there are more illumination loads , no noise is generated in the duty ratio portion, and the stability of the dimming signal detection is improved. .
[0012]
Although the illustrated embodiment shows an example of a rectangular wave lighting with the chopper circuit 80 and the full-bridge type inverter circuit 90 of the buck, the present invention is independent of the circuit configuration of the rectangular wave lighting, the inverter circuit If the operating frequency of 90 and the rectangular wave signal (dimming signal) are synchronized and frequency-divided, the same effect can be expected.
[0013]
As described above, the chopper circuit 80 generates an output corresponding to the load power of the illumination load 3. This point is the same as before, but a little supplementary. Reference numeral 13 in FIG. 2 denotes a detection resistor for detecting the current of the chopper inductor 16. The lighting control circuit 80 detects the voltage of the detection resistor 13 and provides a conduction signal to the chopper transistor 14 when the detection voltage is zero. The conduction signal period is related to the duty ratio of the rectangular wave signal (dimming signal). If the duty ratio is, for example, 75%, the conduction signal period in which the illumination load 3 is 75% bright is selected.
[0014]
【The invention's effect】
According to the present invention, be rectangular wave lighting of low frequency, it is possible to accurately detect only the dimming signal (rectangular wave signal).
[Brief description of the drawings]
FIG. 1 is a system diagram of the device of the present invention. FIG. 2 is a circuit diagram of each device. FIG. 3 is a signal waveform diagram.
5 ... AC power supply
101 ... Power line
6 ... Square wave signal transmitter
102: Dimming signal line
1 ・ 1A ・ 1B ... Light control device
3, 3A, 3B ... Lighting load
80 ... Chopper circuit
15 ... Rectifier circuit
14 ... Chopper transistor
16 ... Inductor for chopper
17 ... Reverse blocking diode
18: Smoothing capacitor
90 ... Inverter circuits 9, 10, 11, 12 ... Switching transistor 7 ... Frequency divider circuit 8 ... Lighting control circuit

Claims (1)

A power supply line wired from an AC power supply, and a dimming signal line wired from a rectangular wave signal transmitter that forms a rectangular wave signal with a variable duty ratio and a constant frequency, the power supply line and the dimming signal line In the dimming illumination device having a dimming device connected to the light source, the dimming degree according to the duty ratio,
The dimming device includes a rectifier circuit that rectifies the AC power supply voltage, a chopper circuit at a subsequent stage thereof, an inverter circuit that converts a DC output voltage of the chopper circuit into an AC rectangular wave voltage, and an illumination load that receives the AC rectangular wave voltage. And
Furthermore the dimmer the rectangular wave relatively low frequency to form a sub waveform divider and said従波shaped raised portion and the falling portion of the value obtained by dividing the frequency receive said square wave signal by an integer dimming, characterized in that it comprises a lighting control circuit for signal said synchronized to match the rising portion or falling portion is not changed even by changing the duty ratio of the drive controls the inverter to light the lighting load Shape lighting device.

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