# Auto-Flushing Toilets & Urinals

**URL:** <https://boards.straightdope.com/t/auto-flushing-toilets-urinals/5006>\
**Category:** Factual Questions\
**Created:** [November 30, 1999, 11:31am UTC](https://boards.straightdope.com/t/auto-flushing-toilets-urinals/5006 "1999-11-30T11:31:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\
**Post date:** [November 30, 1999, 11:31am UTC](https://boards.straightdope.com/t/auto-flushing-toilets-urinals/5006/1 "1999-11-30T11:31:00Z")

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- A chap in one of my classes asked this tonight. I didn’t understand the question, so we went into a bathroom and made like Beavis and Butthead. It’s easy to see the red plastic window on the front somewhere; I’d guess that IR detection is involved somehow, which means you’d need electricity - but no wires run to the thing! The ones we looked at seem to be just a box that mounts over the place where the handle used to be. How does it get it’s power? - MC

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**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\
**Post date:** [November 30, 1999, 11:58am UTC](https://boards.straightdope.com/t/auto-flushing-toilets-urinals/5006/2 "1999-11-30T11:58:00Z")

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WAG: There’s a low-level, long-life battery within the IR box that gets replaced periodically.

I tried to imaging some through-the-piping electrical supply, but I couldn’t eliminate one wire.

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**Author:** ![Guy\_Propski](https://avatars.discourse-cdn.com/v4/letter/g/5e9695/32.png) [@Guy\_Propski](https://boards.straightdope.com/u/Guy_Propski)\
**Post date:** [November 30, 1999, 1:36pm UTC](https://boards.straightdope.com/t/auto-flushing-toilets-urinals/5006/3 "1999-11-30T13:36:00Z")

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AWB–you’re right, it’s battery powered. The battery lasts about a year.