Chicken supplementary light to increase egg production rate circuit

(1) Circuit composition The chicken farm automatic fill light circuit consists of a power supply circuit, a photometry circuit and a dimming circuit , as shown in Figure 8-18.
    The power circuit consists of power switch S, power transformer
T, rectifier diodes VD1-VD4, filter capacitors 6,
G, i-side voltage stabilizing integrated circuit IC, current limiting resistor and
power indicator light-emitting diode I. ED composition.
    The photometry circuit is composed of photoresistor RG, potentiometers
RP1, RP2, resistors R], R2 and transistors VT1-
VT3.
    The dimming circuit consists of transistor VT3, single-junction transistor
BT33, thyristor VTH, resistor island, flat capacitor, capacitor
Ci and fill light Ar:_EL.
    (2) Circuit principle: AC 220V voltage is stepped down by T
and rectified by VD1~VD4. After C2 filters and 1c stabilizes the voltage to +9V, it is used as the working power supply of
the photometry circuit and the dimming circuit
, and at the same time the LED is lit via the ruler.
    When the natural light is strong during the day, RG is in a low resistance state, VT1-VT3, BT33 and VTH are all in a cut-off state, El. not bright.
    When the light dims on rainy days, the resistance of RG increases, causing VT1 ~ VT3, BT33 and VTH to all conduct, and EL lights up. The darker the light,
the greater the conduction current of VT1~VT3, C, and the faster the charging speed. The trigger pulse generated by BT33 increases the conduction angle of VTH, and
the stronger the EL luminescence brightness.
    Adjust the resistance of RP1 to adjust the sensitivity of the fill light action.
    Adjusting the resistance of RP2 can make the fill light change smoothly with changes in external ambient light.