Timed smoke detection
OwnerDavid E. Perelli, Stephen J. Perelli +1inventors
InventorsDavid E. Perelli, Stephen J. Perelli, John B. Jenkins, II
Life of this patent
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Abstract
A smoke detector includes a sensing unit which has a power terminal adapted to receive electrical energy. A timing device in the smoke detector includes a switch, a timer and a manually operable device. The switch is coupled to the power terminal for interrupting current thereat. The timer can operate the switch to cause interruption of current at the power terminal for a predetermined interval. The manually operable device can actuate the timing means and start its predetermined interval.
Claims13
In a smoke detector having a sensing unit, said unit having a power terminal adapted to receive electrical energy, a timing device comprising:
- switch means coupled to said power terminal for interrupting current thereat, said switch means being operable to dissipate less power when interrupting current at said power terminal;
- timing means for operating said switch means to cause interruption of current at said power terminal for a predetermined interval, said timing means and sensing unit having a common potential line, said switch means having a control terminal and a pair of switched terminals controlled thereby, the terminals of said switch means carrying potentials constrained within upper and lower limits, one of said limits being established by the potential on said common potential line;
- and
- manually operable means for actuating said timing means and starting its predetermined interval.
A smoke detector comprising:
- a sensing means having a power terminal for providing an alarm signal in response to smoke;
- a switch means coupled to said power terminal for interrupting current thereat, said switch means being operable to dissipate less power when interrupting current at said power terminal;
- timing means for operating said switch means to cause interruption of current at said power terminal for a predetermined interval, said timing means and sensing unit having a common potential line, said switch means having a control terminal and a pair of switched terminals controlled thereby, the terminals of said switch means carrying potentials constrained within upper and lower limits, one of said limits being established by the potential on said common potential lines and
- manually operable means for actuating said timing means and starting its predetermined interval.
A method for operating a smoke detector in an occasionally smoky environment with a pulse generator and a switch, comprising the steps of:
- manually actuating said switch to remove power from said smoke detector but not said pulse generator when smoke is observed;
- counting pulses from said pulse generator;
- operating said switch to restore power to said smoke detector after the expiration of a predetermined interval, whose duration is measured by the occurence of a predetermined number of pulses;
- manually actuating said switch to restore power to said smoke detector if smoke is no longer observed before the expiration of said predetermined interval.
Dependencies are inferred from the claim text.