Child Guard
Approx construction cost US$48
The design produces a coded infrared beam, which detects the proximity of a person by bouncing infrared off them as they approach, yet without being confused by other infra-red sources. A separate sensor detects the random infrared radiation being emitted from a hot fire. If anyone approaches the fire, a warning buzzer sounds.
The system can be used in many ways, but the main intention is to give a parent a warning if their child approaches a heat source, such as a fire. It is especially useful if they have inquisitive babies who are beginning to walk. Another use could be to warn blind or partially sighted people if they are about to touch something dangerously hot, such as a stove.
More details on this construction project can be found in the September 1999 issue of EPE Online, the world's first web-delivered electronics and computing hobbyist magazine.
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