Jeenode infrared project part 5: extending IR range

Ok, so my IR controller has been running for a while. Though I was only using it for receiving for now.
The range of the IR LED was not sufficient enough to control my devices. Today I had a look into the hardware schematics.
I increased the transmitting power by using a NPN transistor (BC549).

Here’s the schematic I used (all at 5V, USB power):

Using this schematic I doubled the range of my IR LED, the power drawn in the circuit is now 37mA. My former circuit, without using a NPN transistor drew 20mA (JeeNode max per digital pin). So that’s almost twice the power.
You could increase this even further using smaller valued resistors, but that would push the boundaries of the LED and transistor. I didn’t need any bigger range anyway as I use IR emitter cables attached to my devices.
Now that I’m satisfied with the hardware part of sending I can start looking at the software side!

p.s: here’s a picture of the box right now.. cables anyone?


Hi, I am Maarten and I am the owner of this weblog. I post on various IT subjects that matter in my life as an IT professional.

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