The Infra Red signals are widely used in wide range of remote control applications so it is worthy to know about the transmission and receiving the IR signals.Here the above circuit was a simple Infrared receiver circuit constructed using IC 555 and TSOP1738.The TSOP1738 was nothing but a simple IR detector used widely and here it was used for the same detecting purpose and then the signal was fed into the IC 555 which was wired as monostable multivibrator.Lets move in to the working of the above circuit.
WORKING OF INFRARED RECEIVER CIRCUIT:
In this above circuit the TSOP1738 forms the main constituent of this circuit and this was designed to detect the IR signals from any source.This was used to detect the signals of the range of 38 KHz and thus named as “TSOP1738” and last two numbers of each of this TSOP series was named for their receiving frequency range.The pin configuration was given below.
The Vs was connected to 5v power supply and the GND to ground respectively.And the output was taken from the OUT pin.The TSOP gives high signal as output in the absence of detection of any IR signals and low output whenever IR signals incident on TSOP1738.This logic was used in the above receiver circuit to to detect the Infra red signals.
Since the IC 555 was wired as monostable multivibrator the negative trigger to the pin 2 of the 555 IC will result in a high output at the 3 pin of the IC 555 thus indicating that the detection of Infra Red signals.But in the absence of IR signals the TSOP will give a high positive trigger thus there will be no output obtained from the 3rd pin of the IC 555.By this way the receiver circuit using TSOP1738 and IC 555 works.