I am making a small IR Switch circuit and using TSOP1738. I am new though. UNDERSTAND thAT With an IR Signal the TSOP1738 Output goes low. when i checked with my MULTIMeter for a VSS of 4V, the output flips down to 3.5 in the multimeter and then jumps back to 4V. I do not see it going near 0volts. pl. advice if my understanding right or the TSOP Sample is faulty. thank you.

 

TSOP detectors need a very specific signal at 38KHz to trigger them, did you provide that?

 

I didn't look up this one but most also don't stay low indefinitely even the signal is steady.

 

I didn't look up this one but most also don't stay low indefinitely even the signal is steady.

The one I have used stops operating if the signal is constant, you have to do bursts of about 10 cycles followed by a quiet period to keep it responding. Data is encoded in long and short bursts of carrier.

 

It's possible the TS's multimeter is responding too slowly to show the drop to 0V, if in fact that is even happening.