论文部分内容阅读
本文介绍一款 DTMF 红外近程探测器,其电路原理如附图所示。以红外发射器和接收器组成的 DTMF 电路用作近程探测器。红外发射管 IR 与红外接收管——光敏二极管之间的距离约12cm。该探测器可以探测到能反射红外线并在红外发射管前移动的任何物体。该探测器使用一般市售的电话集成电路,发射部分使用一只拨号音调发生器91215B(IC1),接收部分使用一只 DTMF 解调器 CM8870(IC2)。供电电源为+5V。发射器部分由 IC1和 IR 等元器件组成。IC1由 ZD1稳定+3.3V 电压供电,R9为 ZD1的限流电阻。R16和 R1组成分压电路,由于其阻值都为100kΩ,故分压值为2.5V。IC1第(11)、(15)脚分别和T2的发射极、集电极相接。刚接通电源,+5V 电压经 R16向 C1充电,经一段时间的延迟后,IC1、T2等组成振荡器连续产生包括697Hz 和
This article describes a DTMF infrared proximity detector, the circuit shown in the figure. A DTMF circuit with an infrared transmitter and receiver is used as the proximity detector. Infrared emission tube IR and infrared receiver tube - photodiode distance between the about 12cm. The detector can detect any object that reflects infrared and moves in front of the infrared launch tube. The detector uses a commercially available telephone integrated circuit with a dial tone generator 91215B (IC1) for the transmit part and a DTMF demodulator CM8870 (IC2) for the receive part. Power supply is + 5V. Transmitter part by the IC1 and IR and other components. IC1 is powered by ZD1 + 3.3V and R9 is the current limiting resistor of ZD1. R16 and R1 constitute a partial pressure circuit, because of its resistance are 100kΩ, so the partial pressure value of 2.5V. IC1 (11), (15) feet and T2 respectively, the emitter, the collector phase. Just connected to the power supply, +5 V voltage charged to the C1 by R16, after a period of delay, IC1, T2 and other components of the oscillator, including continuous generation of 697Hz and