I'm doing a bidirectional visitor counter.i m using TSOP 1738 at receiver side,and 38KHZ astable multivibrator at transmitter side.everything works fine.but it can't work if the distance between Tx,Rx is above 8cm.It's very short distance,so i can't use it in real time.I picked up sony IR LED from my old TV remote.now also it can't works for long diastance.I have attached my circuit diagram.I have used R1=1k,R2=1.394k,c=0.01up.
please...... help me!

 

One thread per subject is enough. I am closing this one so discussion may continue at the other.

http://forum.allaboutcircuits.com/showthread.php?t=62500