Help understanding an IR Receiver circuit.

Submitted by Andre on Fri, 04/19/2019 - 10:30

I am using the following circuit from https://circuitdigest.com/electronic-circuits/ir-transmitter-and-receiver-circuit as an IR Receiver.

When I stand far away and point a TV remote at it and push a button, the LED lights up; hence it appears to be working. However if I get within 1m of the sensor i.e. just stand in front of it without the remote, the LED flickers continually - almost as if a signal is bouncing off of me.

The sensor that I am using is not a TS0p1738 but rather the following: ZD1952 

I therefore have two questions:
1) Why does the LED shine when I stand near the sensor but if I am further away only when pressing the remote.
2) Do I need to make same changes to accommodate the fact that the receiver is a ZD1952?

I appeared to have a cold joint. It seems to have come right now. Also I flipped the PNP as apparantly this is the wrong way round in the diagram.

  Joined April 19, 2019      1
Friday at 10:26 AM

So it it working now?

Remeber the LED glows for any signal picked up buy your sensor. Since the sensor picks up IR light, there are chance that it uis responding to sunlight. Since the sunlight also as IR light 

  Joined August 11, 2018      35
Saturday at 01:52 PM

jaksonlee

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IR Receiver circuit is very simple we just need to connect a LED to the output of the TSOP1738, to test the receiver. We have use BC557 PNP transistor here, to reverse the effect of TSOP, means whenever the output is HIGH LED will be OFF and whenever it detects IR and output is low, LED will be ON.

  Joined November 07, 2019      124
Thursday at 04:25 PM