Infrared reflective automatic light circuit

It is a real-chip infrared bean- beam automatic light circuit. When you approach, the light will turn on;
when you leave, the light will automatically go out. It can be used in home storage rooms, sanitary lighting or dressing table mirror headlights and other occasions.
    The infrared reflection module Al is equipped with an infrared luminous tube and an infrared receiving tube installed side by side. After being powered on, the infrared and
external luminous tubes emit graceful infrared rays with a frequency of 40kHz. When there is no object blocking the front, the infrared
receiving tube cannot receive the infrared light emitted by the luminous tube, and there is no signal output at the output terminal OIJT, so the tube VI is in
a cut-off state. Because of capacitance C. It is fully charged, the ⑥ pin of 12 is high level, the time base circuit A2 is in reset
state, the output terminal ③ pin is low level, the relay K does not act, and the lamp F does not light up. When someone approaches in front,
the infrared rays will be partially reflected back and received by the infrared receiving tube. After amplification, decoupling,
shaping , the output terminal OUT suddenly changes to a high level. ． , G smoothing makes VT conductive.
On the one hand, the trigger pin ② of the time base circuit is at low level, A2 is set immediately, the output pin ③ suddenly changes to the commercial
level, the relay K absorbs the platform, the contact kl is closed, and the lamp F lights up; on the other hand , VT is turned on so that
the charge charged by C can be discharged. When the person leaves, the () LIT end of Al returns to low level and vr is cut off. At this time, the positive power supply of f passes
through RP and R to C. Charge. When charging to the power supply voltage 2;3, the time base circuit A2 flips to the reset state,
pin ③ outputs low level, the relay is released, and the light goes out.
    Al uses the infrared reflection detection module TX05D produced by Tianjin Texin Electronics Factory (littp://www.texin.corn.cn).
The module appearance is shown in Figure 189 (h). The front side of the module is equipped with an external receiving tube and an infrared
light-emitting tube side by side. There is an LED indicator light and a sensitivity adjustment hole on the side. The indicator light is used to indicate
the working status of the module. Normally, the light goes out. Once there is a reflective obstacle, , the indicator light glows. The adjustment hole is used to
adjust the reflection detection distance. The detection distance of the module is also related to the level of the operating voltage. The higher the voltage, the greater the detection distance, and vice versa
. The nominal operating voltage range of the module is 5-12V, and the corresponding maximum detection distance is 0-120cm.
The outer wire of the module is a strong core shielded wire about 2m long. The shielding layer is the negative power wire, the red core wire is the positive power wire, and
the white core wire is the signal output wire OUT.
    The specific installation of the circuit indoors depends on the purpose. If it is only used for ordinary delay lighting, the Al can be fixed
in the lifting and closing box on the wall, and the sensitivity of the module is reduced to -lit. The detection distance is only L80m. That’s it.
When turning on the light, just shake your hand in front of the module and the light will light up. Then adjust the micro-8 resistor RP to make the delay time
appropriate. If the delay time is too small, you can increase the capacity of G. If it is used to call the toilet in an earthen bedroom,
install the Al near the toilet and adjust the detection sensitivity higher so that when someone comes in, the light can be
lit. If it is used to control the bathroom or dressing table mirror headlight, the Al should be installed near the front of the mirror.
When someone looks in the mirror, the light will turn on, and the circuit delay time should be adjusted smaller, so that when the person stops, the light will go out. Since most master bedroom
bathrooms and storage rooms have windowless structures, the call lights are not equipped with light control circuits .