.4 04.A
ADJUSTMENT | 8. Adjustment of Brightness Control Circuit |
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8.Adjustment of Brightness Control Circuit (Fig. 51, 52)
!) Tum off the power switch 51 ( ~ ).
2)Fully tum ( ~ ) the shait of variable resistor VR 3 in the DC ammeter M 1 ( @), counterclockwise.
3)Fully tum ( ~ ) the shait of variable resistor VR 1 (e@ ) in the printed circuit counterclockwise.
4)Change over the power
5)Set the power voltage to AC 1OOV ± 1%, 5 Hz.
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6)Connect the thermostat·type voltmeter (over l .5 class) for measuring the lamp voltage to the terminal of the lamp.
7)Plug the power source cord into the socket.
After connecting the halogen lamp of l 2V, SOW with the lamp socket.
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8)Tum on the power switch S1 ( ~ ).
Do not tum the power switch dial beyond the position where the swttch is just turned ON (at a maxirnum voltage of variable resistor VR1 ( ~ ).
ln this position the brightest illumination will be obtained .
9)Slowly tum thP. shaft of variabie res1stor VR 1 ( ~ ) in the printed circuit, clockwise, and then the illumination oi the lamp will be slowly darkened.
Stop this tuming at the position where the lamp filament looks dim.
Do not tum the shaft beyond this limit, because the lamp will glow suddenly.
10)Tum the dial of power switch S1 ( ~) in the direction in which the voltage of variable resistor VR2 ( @ ) becomes lower, until the
indicates 9.0V.
11)Tum the shaft of variable resistor VR 3 ( ~) for sensitivity adjustment, clockwise, so that the DC ammeter M1 (@ ) indicates 9 .OV.