38KHz generator for IR LED

Thread Starter


Joined Aug 31, 2012
Dear everyone,

I have a design of 38KHz generator for IR source. The problem is practical value differs lot from theoretical. I know the resistance tolerance will affect the output and also i want to know if any other parameter affects the frequency. Please give your advice.


Joined Aug 7, 2008
At 38 k Hz, timing cap is small & film type, relativley stable. Tolerance not a problem because timing R is part pot. The IR receivers I've tried had broad tuning, several k Hz wide.


Joined Apr 24, 2011
Based on the information supplied, the frequency will vary from between zero and infinity.

Post schematic and parts list for a real answer... but don't expect anyone to actually search out the specs of all the parts. That's your job.

We can point you in the direction. We're not going to do your grunt work for you.


Joined Mar 24, 2008
I would use a 555 circuit, but it is probably not as stable as you probably want. This is a situation where more information is needed.