Emergency power-out only bubbler

[daytonians]

Here's an idea. Could someone design a battery back-up that would only switch on if the power is out?

I would like to have a bubble bar in my tank for emergencies only. The air pump would only be on if the power is out. This would supply oxygen and some laminer flow till the power came back on.

I have used a bubble on a battery back-up before, but I really don't want the bubbles running all the time.

[MayoBoy]

http://mistressreef.homestead.com/files/DIY/diy.html#UPS

[jmccalip]

http://www.petdiscounters.com/product.php?productid=1093393&cat=949&page=

This pump is automatic! When the power goes off, the pump goes
on! It's like life insurance for your fish. All you have to do is plug this pump into the wall and it detects when the power goes out, even when you are asleep or not at home. Built-in on-off switch. Can be unplugged from wall and used as a portable pump. Operates on (2) D-Cell batteries. (Batteries not included.) Includes 18" of flexible silicon airline tubing and a small air stone. Each unit measures approximately 5-1/2" x 3-1/4" x 1-1/2". Power cord is approximately 3 feet long. Small clip mounted on back of unit to clip on the edge of bait buckets or your belt. 110V - 60 Hz operation only.



I use two of em'. They work great, but they're loud(same with all battery air pumps).