how to make stronger beam infrared?


how to make stronger beam/signal infrared? currently i just using two leg infrared (diode) transmitter and receiver. i give 4 batteries AA 1.5v, and 200 ohm resistor for transmitter. And i give 1k resistor for receiver, the power is 5v (using arduino board). By doing these i get low signal for 2 meters distance. can someone tell me how to make stronger signal, maybe put another module such as transistor or other things in transmitter part so it can give more signal. I am not really familiar with electrical module.


More transmitter LEDs might help: you could put a couple in series, with a smaller resistor. Also note that different LEDs have different beam widths: one with a 20-degree field-of-view will transmit much further than one with a 50-degree FOV, because the energy is concentrated on a smaller area. But it has to be aimed more carefully when you're close to the receiver.

Also, double-check the specs on your LED: IRLEDs often have different voltage and current requirements from visible LEDs, and you may not be giving it enough power. Unless you're secretly a robot, you won't see the problem like you would with a red or green one.