Pyroelectric infrared induction automatic light circuit (6)

Is one using HN9111. An induction automatic light made of a novel pyroelectric infrared detection module , HN I911L integrates a high-sensitivity infrared sensor PIR, amplifier, signal processing circuit, output circuit , etc., which can remotely measure the weak infrared signals emitted when the human body moves. In this circuit, as long as someone is walking around, the light will automatically light up. After the person leaves, the light will go out automatically after a delay of several P seconds.     VI) 1. A simple capacitor step-down half-transition rectification and stabilizing Jk circuit composed of VSl, r- and bar. After powering on, the capacitor [1: a current voltage of about 12, _ can be obtained at both ends for the j-electrode tubes VT1 ~ VT3 Delay circuit is used. This DC current L passes through VS2_ secondary voltage stabilization and C. Filter to obtain a stable DC voltage of about 6V for the integrated module HN91. When the HN911 does not detect an infrared signal, the second pin outputs a high level, VT1 is cut off, VT2 and wn are also cut off, and VT4 is turned off. , the electric light E does not light up.     When k-people are walking nearby, the infrared rays emitted by the moving human body are received by the sensor outside the cylinder inside the module. After being processed by the internal circuit of the module, pin ② outputs low level, Vl)2 is connected to VTL, and the 12V positive power supply passes through VT1 , VD3 quickly charges Ct, and is sent to the base of VT2 through R; so that VT2 and VT3 are quickly turned on. The thyristor VT4 gets the trigger current through VT3 and R, and the lamp E is immediately turned on. H. If there are people nearby, the lights should always be on. After the person leaves, the second pin of the module will return to high level and V11 will be cut off. However, since the charge stored in c can be discharged to the base of VT2 through R, the light can still be kept on . After about tens of seconds C; the charge is basically discharged, which is not enough to keep VT2 and VT3 on, VT2 and VT3 are cut off, VT4 loses the trigger current, and when the AC crosses zero, the yellow light E turns off. The delay time of the circuit is mainly determined by R. , (the placement is also determined by the pin constant, the reader can adjust it according to needs.     The photoresistor RT is connected across the ④ and ⑤ pins of the module. Together with the adjustable resistor RP, it forms the light control circuit of the lighting lamp. During the day, the resistance value of RI is very small Low, which greatly reduces the gain of the module's internal amplifier. At this time, the module's pin ② has no level input tH1, Vri will not be turned on, so the lamp F will not be lit during the day. To J + night E, RI. Resistance value Increasing the gain of the internal amplifier of the module has little effect, so the module can work normally. Adjust RP to adjust the light control sensitivity of the circuit .     H N9111. It is a micro-power consumption pyroelectric infrared detection module. Its overall dimensions are shown in Figure 1 7tj(∽. When used, if equipped with a finished plastic housing with a Q-IA (j8 8×45mm) Fresnel lens, the horizontal detection angle can reach 85., and the maximum detection distance can reach 1 5m.