JPH0443996Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for setting the dimming level of a lighting load.

BACKGROUND ART In order to individually set the dimming level of multiple lighting loads, variable resistors corresponding to those lighting loads are provided, and each variable resistor is operated by sliding contact with a resistor. One end of these resistors is connected to a common first voltage corresponding to a dimming level of 100%, and the other end of the resistor is connected to a common first voltage corresponding to a dimming level of 100%, and the other end of the resistor is connected to a common first voltage corresponding to a dimming level of 100%. The output from the operation piece which is set to the ground level which is a second potential corresponding to 0% and is in sliding contact with the resistor is read out by sequentially making the switching means conductive one by one. One end of a diode is connected to each operating piece in order to prevent interference by the remaining variable resistors, and the other ends of the diodes are connected in common and connected to a third potential by, for example, a pull-up resistor. In the prior art, the first potential and the third potential are set to the same value.

Problems to be Solved by the Invention In such prior art, when the operation piece is slid into contact with the one end of the resistor, the operation piece comes into contact with the one end and the dimming level is changed.
The diode becomes cut off before it is set to 100%, in other words, the adjustment is made before the operating piece reaches the 100% position of the one end of the resistor. The light level is set to 100% by the pull-up resistor, so it is not possible to accurately set the dimming level according to the displacement of the operating piece, and a so-called inactive area exists.

An object of the present invention is to provide a dimming level setting device that can obtain a dimming level corresponding to the operation piece of a variable resistor that sets the dimming level.

Means for Solving the Problems The present invention consists of a plurality of lighting loads, a switching means provided for each lighting load and sequentially turned on, and a variable light control system that sets a dimming level that corresponds to each lighting load individually. A resistor, wherein one end of the resistor is a first
Such a variable resistor is provided with an operating piece which is set to a potential Vcc, whose other end is set to a second potential GND via a switching means, and which slides into contact with a resistor; diodes whose ends are connected in common, the common portion being connected to a third potential by a pull-up resistor, the third potential being equal to or less than the first potential plus the forward voltage drop of the diode. This is a dimming level setting device characterized by setting the above value.

Effect According to the present invention, the first potential Vcc applied to one end of the resistor, the forward voltage drop of the diode,
For example, the sum with 0.7V is determined to be equal to the third voltage. This eliminates the dead region in the prior art described above due to diode forward voltage drop. This makes it possible to obtain a voltage representing a dimming level corresponding to the amount of displacement of the operating piece.

Embodiment FIG. 1 is an electrical circuit diagram of an embodiment of the present invention. Lighting loads L1 to Ln are driven by drive circuits DR1 to DRn.
The light is energized with power under phase control, and brightness at a predetermined dimming level can be obtained. Channel CH1 that individually corresponds to lighting loads L1 to Ln
~ Variable resistors R11, R21, R31; R12, R22, R3 which are dimming level setters for each CHn
2;...;R1n, R2n, and R3n are provided, and these are arranged for each of the three scenes SC1, SC2, and SC3. The variable resistor R11 is connected between the resistor 11, one end 12 and the other end 13 of the resistor 11.
The remaining variable resistors R21 to R3n also have a similar configuration.
The operating piece 14 is manually operated, and when connected to one end 12, the dimming level is 100%, and when the other end 13 is connected, the dimming level is 100%.
When connected to , the dimming level is 0%. One end 12 is connected to line 15 and has a first potential
Vcc is applied from the DC power supply 16. Resistor 11
The other end 13 is a switching transistor Q1.
is set to the ground potential GND which is a second potential.

Switching transistors Q1-Qn are provided for each channel CH1-CHn. Variable resistor R1
A diode D11 is connected in series to one operation piece 14, and diodes D21 to D3n are also connected to the remaining variable resistors R21 to R3n. Variable resistors R11 to R1 in the first scene SC1
The anodes of diodes D11 to D1n connected to line 17 are commonly connected to line 17. In addition, the diodes D21 to D2n in the second scene SC2 are
Commonly connected to line 18. Similarly, the diodes D31 to D3n in the third scene SC3 are
Commonly connected to line 19. The common contact 21 of the switch 20 is sequentially switched into individual contacts 22, 23, 24 connected to the lines 17, 18, 19. The common contact 21 is connected to a line 25, to which a third potential V1 of the DC power supply 16 is applied via a pull-up resistor 26. The output of the line 25 is converted into a digital value by an analog/digital conversion circuit 27, and is applied to a processing circuit 28 implemented by a microcomputer or the like. A crossfader 29 is connected to the processing circuit 28 . The processing circuit 28 includes each scene SC1 to SC.
The dimming level of each channel CH1 to CHn is stored, and the cross fader 29 performs a crossfade operation, and the drive circuit at each dimming level is stored.
The brightness is controlled so that the dimming level is achieved by activating DR1 to DRn and energizing the lighting loads L1 to Ln. Transistors Q1 to Qn and switch 20 are controlled by a control circuit 30.

The first potential Vcc derived to the line 15 of the DC power supply 16 and the third potential Vcc applied to the pull-up resistor 26
The potential V1 is defined as in the first equation. The forward voltage drops of the diodes D11 to D1n are here equal, for example 0.7V, and are indicated by the reference VD.

V1≧Vcc+VD (1) Referring to FIG. 2, the control circuit 30 conducts only one transistor Q1, Q2, Qn at the same time in the manners shown in FIG. 21, FIG. 22, and FIG. 23. control sequentially so that Transistor Q1~Qn
The period during which each of these is conductive is, for example, 200 μsec. During the period when each transistor Q1 to Qn is conducting, the common contact 21 of the switch 20
The switching mode is sequentially changed so that only one of the individual contacts 22, 23, and 24 is conductive at a time, as shown in FIGS. 2, 4, 5, and 6, respectively. In this way, the dimming levels set by the variable resistors R11 to R3n of the channels CH1 to CHn are stored in the processing circuit 28 via the switch 20 and the analog/digital conversion circuit 27.

In the variable resistor R11, when the operating piece 14 is operated and displaced from the other end 13 toward the one end 12, the third voltage V1 becomes the first voltage.
Forward voltage drop of diode D11 than Vcc
Since only VD is set high, that operation piece 1
4 reaches said one end 12, its diode D11 remains conductive. Therefore, in the line 25, the operating piece 14 can set the dimming level from 100 to 0% over the entire range of the ends 12 to 13. In this way, it is possible to set the displacement amount of the operating piece 14 and the dimming level in a linear proportional relationship. Therefore, the dead area mentioned in connection with the prior art described above can be avoided.

Effects of the invention As described above, according to the invention, it is possible to obtain a voltage corresponding to the amount of displacement of the operation piece that sets the dimming level of the variable resistor, and the non-operating area in the prior art described above can be overcome. Can be removed.

[Brief explanation of the drawing]

FIG. 1 is an overall electrical circuit diagram of an embodiment of the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the control circuit 30. L1-Ln...Lighting load, DR1-DRn...Drive circuit, SC1-SC3...Scene, R11-R3n...
...Variable resistor, D11-D3n...Diode,
Q1~Qn...Switching transistor, 11
...Resistor, 12...One end, 13...Other end,
14... Operation piece, 20... Switch, 26... Pull-up resistor, 27... Analog/digital conversion circuit, 28... Processing circuit, 29... Cross fader.

Claims (1)

[Scope of Claim for Utility Model Registration] A plurality of lighting loads, switching means provided for each lighting load and sequentially turned on, and a variable resistor that sets a dimming level individually corresponding to each lighting load. One end of the resistor is the first
Such a variable resistor is provided with an operating piece which is set to a potential Vcc, whose other end is set to a second potential GND via a switching means, and which slides into contact with a resistor; diodes whose ends are connected in common, the common portion being connected to a third potential by a pull-up resistor, the third potential being equal to or less than the first potential plus the forward voltage drop of the diode. A dimming level setting device characterized in that the dimming level is set to the above value.