Monday, August 09, 2010

How should a device warn you that its batteries are getting low?

In 1969 I worked at a company that developed both hardware and software, and for the first time, I met [i]hardware people[/i]. I remember one of their fancies: to imagine a machine that would warn you it was not plugged in, by lighting an emergency light.

How should a device warn you when its batteries are low? Our wireless doorbell uses as bizarre a strategy as I can imagine. A few months ago, the doorbell rang. Our device uses the "Big Ben" tones, which take a few seconds to play. There's no mistaking them. I rushed to the front door, but nobody was there. A day or two later, the same thing happened. When it happened five times in one day -- gee, all those false alarms -- I figured it was time to throw the darn thing away, but first, I might as well try changing the batteries. And that solved the problem.

Why am I writing about this now? There was nobody at the front door this morning...


Anonymous said...

I'm amusing myself with a mental image of you running back-and-forth trying to catch the person ringing your bell. Perhaps you always suspected an equipment failure...or maybe you made a mental list of suspects as you laid in wait for the puerile SOB who had nothing better to do than wreck your day.

Have you already changed the battery?

Anonymous said...

Smoke detectors use the same strategy, "chirping" when the battery gets low.

The first time I installed one, and it ran down, I was wondering how/where a cricket had gotten into my house, that was chirping so regularly. Then I figured it out.

The Precision Blogger said...

Anon #2, Smoke detector do not use the same strategy. If they did, they would wail away, and everyone would drop what they were doing and run out of the house in their undies, and then discover that there was no fire.
- PB