This home smoke detector circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire and passes between a bulb and an LDR, the amount of light falling ...

At the heart of this ultra simple smoke alarm is H21A1, which is a photo-interrupter module consists of a gallium-arsenide infrared LED coupled to a silicon phototransistor in a plastic housing. The ...

If you’ve ever lived through a house fire, you know how devastating it can be. The fear of fire leaves many homeowners anxious, especially when they are away from home. The Leeo Smart Alert is here to ...

Q: I changed the batteries in my smoke detector, but when I tested it afterward nothing happened. The batteries are new, but the smoke detector is very old. I know that it’s hard-wired into my home’s ...