FITTING A SMOKE ALARM makes a lot of sense. For not much more than $10 – including a battery – they offer peace-of-mind and security, especially while the family sleeps.

Typically though, the one place they are not normally fitted is the one place they should be – in bedrooms. That extra few minutes (or even seconds) of warning time could literally be the difference between life and death.

Take one low-cost battery-operated smoke detector, add a little extra circuitry and an intruder detection device or two... and you have a low cost, battery-operated smoke detector which screams its head off when there's smoke or intruders. It's simple to build, too!

But smoke detectors in bedrooms, especially teenage kid’s bedrooms, aren’t cool. They don’t want ’em! What they really want is something to keep little brother or sister out while they’re not home. The "keep out" sign on the door doesn’t work real well, even if it does threaten some exotic disease to anyone entering except the occupant.

Where is all this leading? Well, how do you think they’d like an alarm system which will keep a sibling at bay? It just happens to look like a smoke detector and yes, it will shriek its head off if there is smoke in the room (darn! now they can’t smoke in their bedrooms...).

Well, here it is. The SILICON CHIP ROOMGUARD looks and works just like a typical smoke detector – mostly because it is a typical smoke detector with its normal action completely unchanged! But it’s much more.