38KHz LONG RANGE TRANSMITTER

Hey guys, can anyone (who knows or who have this board) give me please a circuit of this IR emitter?

I just want to try this at home now (bcs i've all of these parts) instead of waiting a month to arrive from Ali 0_o

Have a nice day and thank you! :slight_smile:

It’s a simple 38 khz oszillator, built with a NE555. SIG== HIGH → 38kh out on LED.

Google "555 38 khz oscillator schematic" for many examples, but it should be easy to deduce the circuit for the board you show.

if what you want is a circuit using this device, not a schematic of the device: Arduino projects - Arduino Project Hub

Are you going to power this board with 5volt?
Then it's not really going to be 'long range'.
The NE555 (bjt) with 100 ohm LED resistor (the one marked 101) might be pulsing 20mA into that LED.

The same (or better) can be done with a 5volt Arduino, a 100 ohm resistor for the IR LED, and a few lines of code.
Leo..

const byte IR_LEDpin = 11; // IR transmitter LED with 100ohm (minimum) CL resistor

void setup() {
  pinMode (IR_LEDpin, OUTPUT);
  TCCR2A = _BV (COM2A0) | _BV(WGM21);
  TCCR2B = _BV (CS20);
  OCR2A =  209; // ~209 = ~38kHz | ~219 = ~36kHz
}

void loop() {
}

If you want long range you can use lenses to collimate the beams at sending and receiving end, or up the power
of the IR emitter.