JPS5931840B2 - lamp stage dimmer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention connects a plurality of lamps 1 to a power source 3 via a phase control element 2, and controls a current bypass element 4 that allows a predetermined current to flow through the connected lamps 1 during a period when the lighting voltage is inactive. A phase control element that is connected in parallel to the control element 2 and adjusts the phase control angle of the lighting voltage according to the number of lamps so that the lighting output of each lamp 1 is the same as in the case of one lamp, regardless of the number of lamps 1 connected. This relates to a step-by-step dimming device for lamps characterized by being provided with a control angle adjustment element 5, and its purpose is to control the step-by-step dimming of each lamp even if the number of lamps changes when performing step-by-step dimming using a plurality of lamps. An object of the present invention is to provide a stage dimmer device for a lamp in which the light output of the lamp is kept constant and the dimming ratio is constant.

FIG. 2 shows a conventional example of the present invention, in which the phase control element 2
An example is shown in which three lamps 1 connected to the power supply 3 via the It becomes abnormally high, and there is a risk that the starting element 6 of a glow lamp or the like may be restarted during dimming. For this reason, a current bypass element 4 is connected in parallel with the phase control element 2 to allow a weak current to flow only during the lamp current pause period. However, in the conventional example as described above, when the number of lamps 1 increases, the current shunted to each lamp 1 through the current bypass element 4 becomes smaller, and the lighting output of each lamp 1 decreases. The drawback was that a constant dimming ratio could not be obtained. The present invention has been devised to eliminate the above-mentioned drawbacks, and one embodiment thereof is shown in FIG.

In the figure, 1 is a lamp like a fluorescent lamp, 2 is a phase-locking element, and 3
is a commercial power supply, 4 is a current bypass element consisting of a resistor, 6 is a starting element such as a glow lamp, 7 is a ballast, 51 to 5
4 is a switch connected in series to the lamp 1. The phase control element 2 includes two three-terminal bidirectional thyristors 8,
9, a trigger element 10, a trigger capacitor 11, a silver current resistor 14, and the like. Further, between one end of the trigger capacitor 11 and one end of the current uniform resistor 14, there are a plurality of resistors R1, R2, R3, whose resistance values are different in stages.
R4, and a common terminal 13 which can be switched and connected to any resistor R1, R2, R3, R4 among the resistors R1, R2, R3, R, is connected to the place card capture elevation angle adjusting element 5. be. Here, the number of resistors R, , R2, R3, and R4 corresponds to the number of lamps, and the common terminal 13 is connected to the switches 51 to 51.
54, when the switch 51 is closed, the common terminal 13 comes into contact with the resistor R, and when the switches S1 and S2 are closed, the common terminal 13 comes into contact with the resistor R2. Also, the resistance value of each resistor Rl, R2, R3, and R4 is R
1>R2>R3>R4. Next, the operation of the above embodiment and the setting conditions of the resistors Rl, R2, R3, and R4 will be described.

When the switch S1 is closed and only one lamp 1 is lit, the lighting light output of the lamp 1 is set to a certain value, and the resistor R1 is set to correspond to the phase control angle of the lighting voltage at that time.
Set the value of Next, close switches S1 and S2 and
In the case of a lamp, the current flowing through the current bypass element 4 is divided into two lamps 1, and the lighting output of each lamp 1 will be lower than in the case of one lamp. When S2 is closed, the common terminal 13 is also switched and connected to the resistor R2.The firing angle of the three-terminal bidirectional thyristor 8 changes, and the current decreases due to the shunt, and the current decreases due to the shunt. The lighting light output is the same as in the case of one lamp. Furthermore, when the switches Sl, S2, and S3 are closed to turn on the three lamps 1, the common terminal 13 contacts the resistor R3, and the thyristor 8 on both three terminals is connected to compensate for the current in the rest section that is reduced by the shunt. The current flowing through the lamps increases, and even in the case of three lamps, the lighting output of each lamp 1 does not decrease compared to the case of one lamp. Below 4
The same applies to lights. As described above, the present invention provides phase control angle adjustment that adjusts the phase control angle of the lighting voltage according to the number of lamps so that the lighting output of each lamp is the same as in the case of one lamp, regardless of the number of connected lamps. Since the device is equipped with an element, when performing stepwise dimming by changing the number of lamps connected, the lighting output of each lamp can be kept constant even if the number of connected lamps changes, and the connected lamps can be Even if the light intensity increases, the light control ratio remains constant, which has the effect of allowing accurate light control.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional example, in which 1 is a lamp, 2 is a phase control element, 3 is a power supply, 4 is a current bypass element, and 5 is a circuit diagram of a conventional example. Phase control angle adjustment element.

Claims (1)

[Claims] 1. Connect multiple lamps to a power source via a phase control element, connect a current bypass element in parallel to the phase control element to flow a predetermined current to the connected lamps during the period when the lighting voltage is inactive, and Staged dimming of a lamp, characterized in that it is provided with a phase control angle adjustment element that adjusts the phase control angle of the lighting voltage according to the number of lamps so that the lighting output of the lamp is the same as in the case of one lamp. Device.