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Looking to extend coverage in a wider pattern/coverage.
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Please be positive and constructive with your questions and comments.

Looking to extend coverage in a wider pattern/coverage.

by Scottbrennan on Sun Dec 31, 2017 10:11 am

New form member but not to electronic kit building. Looking to extend the coverage in a wider circular pattern. Thank sports bar with TVs on several walls. Anyone have ideas? Can I put additional IR ILEDs in parallel or will that cause power draw issues. Thoughts? I did poke around the forum but didn’t see anything Thanks In advance

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Re: Looking to extend coverage in a wider pattern/coverage.

by adafruit_support_bill on Sun Dec 31, 2017 10:59 am

There are a few ways to approach it. But beaming power over a wider area means a trade-off between power and range.

One way to increase coverage is to replace the two narrow-angle LEDs (the blue ones) with wide-angle LEDs (the clear ones). Then bend the leads on your LEDs to fan them out about 40 degrees apart. Each of these leds has a coverage of about 40 degrees, so 4 of them should get you up to about 160 degrees.

To increase the coverage beyond that, you will need more LEDs - and it will take more power to drive them. For each additional LED you would need an additional 2n3904 transistor and a 120 ohm resistor as in the schematic below. In theory, 9 LEDs angled 40 degrees apart would give you 360 degree coverage. But since the optics are not so precise, you would probably want to plan on more LEDs with a bit of overlap in coverage. 12 LEDs at 30 degrees apart should do it.

Image

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Re: Looking to extend coverage in a wider pattern/coverage.

by Scottbrennan on Sun Dec 31, 2017 11:14 am

Thanks for the speedy reply. I see the 3904s but not the 120k resistor on the schematic. Maybe I’m missing it ( its not New Year’s Eve yet so _that_ can’t be the problem with me... yet)

Also you said power would suffer. Because of the additional power draw on the power source?

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Re: Looking to extend coverage in a wider pattern/coverage.

by adafruit_support_bill on Sun Dec 31, 2017 12:03 pm

I see the 3904s but not the 120k resistor on the schematic.

Sorry, I was looking at an earlier version of the schematic. No need for the resistor in this version.

Also you said power would suffer. Because of the additional power draw on the power source?

Using the wide-angle LEDs, the power is dispersed over a wider area, so the range will not be as far. And it will take additional power to drive the extra LEDS, so your batteries will not last so long.

The battery issue is probably not a big problem, since you would not be running it continuously.

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Please be positive and constructive with your questions and comments.