Automatic emergency light circuit

Automatic emergency light circuit

Shown is an automatic emergency light circuit using an electronic switch integrated circuit. The automatic emergency light made with this circuit does not work when there is sufficient light during the day
, but can automatically light up when the light is low at night.
    The circuit shown in Figure 1148 is mainly composed of a power supply circuit, a light control circuit and an electronic switch circuit. During the day or
when the light intensity is high, the resistance value of the photosensitive transistor VSL is small, the transistor VT1 is in a cut-off state, the subsequent circuit does not operate, and the light plate EL does not light up;
when the light becomes dim at night. The VSL resistance value increases, causing the base of the transistor VTI to obtain a voltage value sufficient to cause it to turn on. The subsequent circuit begins to
enter the working state, the electronic switch inside the electronic switch integrated circuit is turned on, and the light bulb EL lights up.