Key finder

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Key finder with sound hole at the bottom

A key finder (ger .: key finder ) is an electronic device, a key rediscover or other objects.

Classic key finder

The key finder is attached to the key as a key fob. To find a misplaced key, a sudden loud noise such as whistling or - on some models - clapping hands is sufficient. If the key finder is in the vicinity of the noise, it gives a sequence of beeps as an "answer". The hearing allowing finding the key, especially when the searched subject is covered by another. Some models are also equipped with a light-emitting diode or other light source and also emit an optical signal.

The range is given as five to ten meters. The key finder is usually a flat square with an edge length of a few centimeters that fits in your pocket. A battery (usually a button cell ) is required for operation. The key finder has been on the market since the late 1980s and is often offered as a promotional gift .

Some key finders not only react to whistles, but also to other, similar noises, for example music or a ringing telephone.

Criticism and advanced key finders

The disadvantage of the classic key finder is that there is no precise analysis of the frequency spectrum, which was not possible with the first models and today would result in computing power with increased power consumption. This leads to frequent false alarms at similar frequencies.

Alternatively, there are now several further developments on the market that prevent false alarms. Models are offered that are either offered with a transmitter in credit card format or with a mobile app that enables communication between key finder and mobile phone, e.g. B. builds up via Bluetooth . This is to prevent false positives.

The volume or frequency of the signal tone emitted by the key finder can also be problematic. U. not audible or locatable for elderly or hard of hearing people.

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