Chicken house automatic fill light circuit

Providing enough light for hens can increase egg production rate. Since the sunshine time is shortened in winter, chicken farmers
generally use the method of artificially turning on lights to supplement the light in the chicken house. If the daylight circuit shown in Figure 297 is used, automatic
light filling can be realized. When night falls, the light will be automatically turned on for about Zh, and then turned off, which will extend the sunshine time by about 2h.
    The 220V alternating current is stepped down by transformer T, VDI-VD4 rectified, and Al[T. M7812) The moon stabilizing box G and
Cz filter output a stable 12V DC voltage for use by the whole machine. The light control circuit is composed of phototransistor VTP, j-electrode transistor
VT and other components. During the day, VTP shows low resistance when exposed to light, and its collector output is low . VT
is cut off and its collector is high level. The time base circuit A2 (NF,555) forms a time timing circuit, and its trigger
terminal ② pin is connected to R, the voltage dividing point r, and the potential is slightly higher than 1/3VDD (V∞ refers to the J2V voltage rE). Therefore, A2
is in the reset state, pin ③ outputs low level, relay K does not operate, and fill light E does not light up. At this time (,. After R,
R, allow electricity, the charge should be positive. When night falls and the color becomes dark, the equivalent resistance of VT1 gradually becomes nine,
making it equal to the voltage dividing point level of RI' Gradually increase, when it rises to a certain value, VT is turned on, and the collector outputs
a low level , c, which discharges to VT and E, causing the level of the trigger terminal ③ of A2 to quickly pull to L/3Vij, as follows .
A2 is triggered to enter the transient state, the ③ pin jumps to high level, K moves to the platform, its movable contact k1 is closed, and
the light F turns on to provide light for the chicken house. After that, C and R. wr charges in the opposite direction to restore the level of pin ② of the trigger terminal
, and it will not change its state. Then the power supply passes through R and charges to 0, so that the level of pin ⑥ of the value terminal continues to
increase . When it reaches the reset level, The 2h timer ends, A2 resets and returns to a stable state, the ③ pin returns to low level, K
is released, and the light E goes out. When the east turns white on the first morning, VTP shows low resistance when exposed to light, VI is cut off, and
its collector jumps again. becomes high level, but this positive transition will not cause A2 to trigger T operation. Only when it is night again,
the circuit fork can be triggered and fill the light for 2h again.
    The principle of A2 forming a time timer is to cleverly use the time base The function of pin ⑤ of the circuit is realized.
There is a voltage divider composed of 3 resistors with the same resistance inside the time base circuit. Pin ⑤ is connected between the first resistor and the first
resistor. The potential of pin ⑤ is It is fixed at 2.73V..L, so the reset level of the time base circuit is
2.3V [J] If the level of pin ⑤ is increased through an external circuit to increase the reset level, delay K can be achieved. Timing
is the purpose of time. In the figure, VD5 is connected to the positive terminal of the power supply and pin ⑤. Assuming the forward voltage drop of the diode is
0.65V, the level of pin ⑤ is fixed at 12-0.65=】1.35V. When pin ② is triggered by a low level
, the circuit is set and the timing starts. The 12V positive power supply charges through R, so that the level of pin ⑥
continues to rise. When it rises to the level of pin ⑤, , the reset timing of the circuit ends. If pin ⑤ is left floating or connected to
the ground through a small capacitor (this is the usual connection method), when the level of pin ⑥ reaches the level of pin ⑤ , that is, 2/3V...-8V, the circuit Just
reset, but now it needs to reach ¨35V before the circuit can be reset and turned into stable state, so the timing time is greatly
extended. The timing time can be up to about 2h using the graphic data. If you want to modify the timing time , can
be realized by increasing or decreasing the capacitance value of c or the resistance bundle of R.
    T uses a 220V/15V, 8VA small high-quality power transformer. K uses a TZC-22F, DC12V small medium-
power electromagnetic relay. E can use several incandescent bulbs in parallel used, but the total power should be controlled below 1000W.
If used in large-scale chicken farms, you can use K to drag the AC contactor to control the light on and off. During installation,
the photosensitive probe (VTI') should be installed in the glass Lead out the leads from the small bottle, seal it with epoxy glass glue at the mouth of the bottle,
and then install it outdoors under the eaves so that it can fully experience the natural light and at the same time be protected from rain and snow erosion.