Free Electronic Circuits & 8085 projects

Electronic projects with circuit diagram and 8085 microprocessor projects.

Infrared body sensor

Published on Jan 20 2011 // Infrared Sensor Cirucits

Infrared body sensor.

The circuit in front of a low-frequency signal amplification, is about 100 times magnification, amplified signals through R6, C5 re-elected 0.2-10HZ signal, and finally sent to a re-IC1B amplification, operational amplifier 5 feet 1/2VCC voltage feet, in the static, the 6,7 pin voltage is 1/2VCC, when there are signals, there will be a 6 feet near the upper and lower voltage in the 1/2VCC voltage swing, the voltage is further amplified by the op amp, input threshold compared to the back of the circuit, the threshold input signal circuit whether you are under 1/2VCC voltage bias or bias, will exceed the threshold in 4148 after the negative diode outputs a high signal. RP1 and RP2 can adjust the sensitivity of detection, the general RP2 can use a 220K resistor instead of, as long as the regulation RP1 on it.