SHOWALL FUN PRANKS HIGH VOLTAGE LAZARUS-64 PHOTOGRAPHY SPY GADGETS VIDEO GAME
Figure 4 - The light spectrum, showing the invisible infrared region
Figure 4 - The light spectrum, showing the invisible infrared region

Infrared light has a longer wavelength than any of the colors on the visible spectrum, crossing into invisibility around 800nm (nanometers), and continuing well beyond 1000nm. Most remote controls use 940nm infrared LEDs, which is why those types are most common and inexpensive. Of course, you could use any infrared LED, even the 800nm - 880nm types often used for night vision illuminations as well. Either way, your buddy (victim) will not see the invisible light so you can hijack the TV or video player in complete darkness without compromising your funny prank.



Figure 5 - An infrared LED datasheet, showing the optimal wavelength
Figure 5 - An infrared LED datasheet, showing the optimal wavelength

If you like to mull over datasheets, then the important factors of any infrared LED are the center wavelength and the forward continuous current, as this will determining what kind of light and how much light you can expect. Of course, for this project, and infrared LED will work, so ratings are not important as the current is low enough due to the supply as well as the short pulses. If you really wanted to get long range from this project then look at the datasheet for the value of pulsed current rating, which is a much higher value than continuous current, allowing the LED to be pushed into extremely bright pulsed mode operation.

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