CS7232 touch stepless dimming light circuit (2)

On the basis of the above example, r-photometering circuits are added, which can be used to transform an ordinary desk lamp into a
special high-blocking eight-light desk lamp for eyesight protection and writing.
    = One-pole tubes VT2 and VT.3 form a Schmitt circuit, and the photoresistor RL (
the ordinary MC45 type photoresistor with a high resistance less than Skn and Anyangdagan 1Mfl and other series photoresistors) is used to feel the tflfi surface, that is, the writing surface. The light
shines on the cliff. When the light eagle calls normally (JOlx), RI shows low resistance, causing VT2 to be turned on, VT3
to be turned off, and the light-emitting symbol T FD is small and bright; if the light illumination is too weak, less than iooix, RI is trapped. The value becomes larger,
the Schmitt trigger flips, wr2 is cut off, VT3 is turned on, and the luminous tube IFD lights up and alarms. Students can touch
M to adjust the light, so that the illumination of the J2 operating surface increases until the LED goes out. Fine-tune RP, Changing the base
level of VT2 can adjust the alarm starting point of the photometric circuit .