Hello everyone,

I want to build a circuit that can sends IR signals through an IR LED at about 38 KHz carrier frequency.

Once I set up the 555 timer to generate the continuous 38 KHz signal, how can I create bursts every time I hit a pushbotton, or send a signal from a MCU ?
I tried using a NPN transistor as a switch that takes the external signal from the base and the 38 kHz signal to the collector, but it doesn't work.

Is it possible to do so still using the 555 or should i do everything on software? (I would like to use the 555 timer to learn more about hardware instead of software)

Thank you in advance

 

hi AM,
Look here.
E
https://forum.allaboutcircuits.com/ubs/tsop1738-when-used-as-a-beam-break-detector.729/

 

hi AM,
Look here.
E
https://forum.allaboutcircuits.com/ubs/tsop1738-when-used-as-a-beam-break-detector.729/

Thank you very much for the advice. I will try the second option with the darlington transistor.
A few questions : the npn couple is in saturation with the hypothesis of 5v at the base right?
Why did you use the second timer with 650 Hz to reset the 38khz timer?What does a reset do?The datasheet says that it simply restart the timer when the reset pin is low, but what does it actally mean?

Thank you