Thyristor dimming lamp circuit with light stabilization function (2)

It is another connection method of
pinjing tube dimming lamp with light stabilizing function . S in the figure
is a light-stabilizing switch. When S is turned on, it is
an ordinary one-way thyristor dimmer.
Its operating principle is shown in Example 26 of this chapter. By adjusting the potentiometer
RP,
the brightness . When S is on the stage, it is automatic light stabilization,
R; and photoresistor RI. It forms a voltage divider and also charges capacitor C through diode VD5. When the ambient light
is dark, RI. The resistance value increases, and the potential at the right end of VD5 increases, so the charging rate to the capacitor C is accelerated, the v:r
conduction angle becomes larger, the voltage across the lamp E increases, and the luminous brightness becomes larger; if the ambient light becomes brighter, the resistance of RI value
decreases, the potential at the right end of VD5 decreases, the charging rate to capacitor C slows down, the VT conduction angle decreases, and
the brightness of the lamp automatically weakens.
    RI. Can chip jM (-, 4, 5 and other non-sealed photoresistors. When making, please note that RL should be installed on
the side of the desk lamp base so that it can feel changes in the surrounding ambient light, but the fork cannot be directly illuminated by its own light. Use
At this time, you only need to turn on the E switch s and adjust the potentiometer RP to select a suitable brightness. The brightness of the electric lamp F will
automatically adjust as the illumination of the surrounding environment changes to ensure that the illumination of the T operating surface is stable.