Street light control circuit 5

This circuit has the advantages of high sensitivity, good temperature stability, and strong anti-interference ability.
    Because the brightness changes slowly at dawn or dusk, this will cause the transistor VTz to be in an incomplete conduction or incomplete
cut-off state. If a directly coupled DC amplifier is used, it will be unstable, so a Schmidt circuit is used. The device's response to brightness
can be adjusted via the potentiometer RPi.
    The function of the capacitor Ci is to prevent the controller from malfunctioning when lightning flashes or other light sources instantaneously hit the phototransistor
at night. The delay time is adjusted by RPz. When the value is shown in Figure 2-94, the delay adjustment range is 5-10s.