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Signing UpStep 1: What You Will Need
- x2 Ultra-Violet LED's. (I purchased mine from Radio Shack for under 2 bucks.)
- x1 100-Ohm Resistor (Again, from Radio Shack. 99cents for a pack of 5.)
- x1 DEAD 9v Battery (or purchased 9v battery clip)
- x1 WORKING 9v Battery
- Pliers
- Basic Soldering Equipment.







































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Is there anyway to make it so that it flashes?
Can I use smaller batteries(a few button cells I need to use it in a very small space)?
Lastly, I want to have the whole thing sealed in a waterproof container/ substance (for a fishtank?) but still be able to toggle it on/off and flash/ steady light, any ideas thoughts would be greatly appreciated.
~Tim
I am never going to purchased any thing from Radio Shack ever.
Thanks for adding the link to the LED calculator. This instructable has been very helpful.
But heaps people then remove them, for powering radios etc, putting back the flat battery from the radio, which came from the detector in the first place too.
We are going to mains powered now, using 9 volters as back up.
Maybe 6-7 years ago, they tried long life lithium 9-volters, the batteries were preinstalled, the detector sealed up by the supplier. However, within months of mine being installed, I needed new batteries.
I made inquiries, and I was told that all the sealed detectors had been railed in shipping containers from Auckland down to Wellington, during a very hot summer, they overheated, and all were screaming out during the trip. Under express freight, it was about 8 hours, more likely it was a broken trip over two days.
A lot of people were disappointed, they thought these lithium batteries would power their radios for 10 years, NO, they had a shelf life of 10 years, the smoke detectors used so little power, it was always the shelf life of a 9-volter that ran out first.
Every year, first cold snap of the Winter, the low battery warning beeps go off everywhere.