Open circuit may refer to:
*
Open circuit breathing apparatus, any type of breathing apparatus where the exhaled gas is discharged to the surroundings without recycling any of it
**
Open-circuit scuba, a type of Scuba-diving equipment where the user breathes from the set and then exhales to the surroundings without recycling the exhaled breathing gas
**
Open circuit surface-supplied diving equipment, a type of surface-supplied diving equipment where the user breathes from the supplied gas and exhales to the surroundings without recycling the exhaled gas
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Open-circuit test, a method used in electrical engineering to determine the impedance in the excitation branch of a real transformer
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Open-circuit voltage, the difference of electrical potential between two terminals of a device when there is no external load connected
*An
open electrical circuit is an electrical network that lacks a complete path between the terminals of its power source
See also
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Closed-circuit (disambiguation)
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Short circuit (disambiguation)
*
Open system (disambiguation)
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