Building bed wetting alarm

Unless you want to do it purely for fun / learning, I recommend hiring a commercial unit if you have the need for one , they are quite effective and not costly.

There may even be a chance that use of an ineffective alarm unit could make matters worse - the above is assuming you have a "real" application. Google "enuresis" alarm if you haven't already.

If you DIY, power it from a couple of AA batteries and _not_ from a plug pack.

regards

Level sensor? what is this for? A whale?

hint, go pee on an electric fence.

What about using a cheap smoke alarm and using the internal 9v battery to power the whole thing? They often have internal room to add other electronics.

I once converted one into a light alarm - all it required was one transistor and an LDR..

It would certainly wake him up if he wet the bed!!! And it would detect if he smoked in bed as well - a very useful project.

Just get a standard 240v cable, cut whatever end is opposite the power point and strip the wires back a bit. Staple them to a piece of cardboard a little way apart. Plug it in and place the cardboard in the middle of the bed. When you wet the bed, you'll learn about it fairly quickly*

Most people will argue that cardboard is a bad idea as it isn't very reusable. Once it gets wet, it loses it's stiffness. However you're unlikely to need to use the above system for more than one bed-wetting.

Cheers! Rick Measham