Temperature discrimination apparatus
AssigneeMulti-State Devices Ltd.
InventorRobert S. Meijer
Life of this patent
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Abstract
A temperature discrimination apparatus is disclosed which comprises a first switching device exhibiting regenerative switching action at a power level which is dependent on the temperature sensed by such first switching device, a second switching device exhibiting regenerative switching action solely in response to a pre-selected power level, means connected to the first and second switching devices for determining if the first switching device has switched before the second switching device in the cycle of the a.c. power source as the magnitude of the voltage increases from zero. This will serve as an indication that the temperature to be sensed has been reached.
Claims7
A temperature discrimination apparatus comprising:
- a. a first switching device exhibiting regenerative switching action at a power level which is dependent on the temperature sensed by said first switching device;
- b. a second switching device exhibiting regenerative switching action solely in response to a preselected power level;
- c. means for simultaneously applying power from an a.c. source to said first and second switching devices;
- and
- d. discriminating means connected to said first and second switching devices for determining if said first switching device has switched ahead of said second switching device in the cycle of the a.c. power source as the magnitude of the a.c. source increases from zero, thus providing an indication that the temperature to be sensed has been reached.
Dependencies are inferred from the claim text.