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 ...

Lee Wallender is a home improvement writer of nearly 20 years and specializes in home remodeling, repair and maintenance. Sami Allen is the managing editor at Forbes Home, with over seven years of ...

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 ...

Lee Wallender is a home improvement writer of nearly 20 years and specializes in home remodeling, repair and maintenance. Sami Allen is the managing editor at Forbes Home, with over seven years of ...