photocell
2
6.2
- noun
- /ˈfoʊtəˌsɛl/
- Specialized
:
fotocelda
- The photocell automatically turns on the lights when it gets dark outside.
- two photocells
Examples
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-A photocell will indicate your presence.
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And so when this bar moves across this photocell, it will activate it.
-
Although small, the increase was enough to register on a sensitive photocell.
Fiction book (1996) -
Hm, we just completed the photocell test and were about to activate the heart system.
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A more powerful light source or more efficient photocells may provide the answer.
Academic text (1995) -
Photocells register light intensity directly, and as a result, they are remarkably accurate but are adaptable over a much smaller range in brightness.
Academic text (2004) -
A photocell used in solar panels measures the sunlight to optimize energy collection.
-
The security system uses a photocell to detect motion and trigger an alarm.
Synonyms
1
6.6
A small device that makes electricity when light hits it to show how bright the light is
1
5.3
A device that uses light to notice when people or objects move
1
9.4
A small glowing tube that shows signal strength on old radios
1
7.2
A device that senses light and makes an electric signal
1
8.1
A small device that lets more electricity pass when light hits it
1
7.4
A small device that changes its electric signal when light falls on it
1
8.6
A tool that measures how bright light is
A device that makes a small electric signal when light hits it to detect or measure light
A part in a camera or machine that detects light and makes an electric signal
How Sensitive
Surface Forms
Morphology
photocell = cell (semi-transparent) = photo + cell
The word is built from the combining form photo- meaning 'light' plus 'cell', but the exact device meaning is only partly predictable from the parts.
Etymology
Photocell comes from photo meaning 'light', as in photograph, and cell meaning 'a small unit' or a small 'battery'. So a photocell is like a little 'light battery' that catches light and turns it into an electrical signal, which is why it is used to detect light for doors, streetlights, and alarms.