Electricity: electrical systems and devices – Safety and protection of systems and devices – With tuned circuit
Patent
1975-12-29
1978-01-31
Miller, J D
Electricity: electrical systems and devices
Safety and protection of systems and devices
With tuned circuit
361 27, 361106, H02H 708
Patent
active
040718751
ABSTRACT:
A circuit is shown useful to protect dynamoelectric machines from overtemperature conditions. The circuit comprises first and second tuned circuits coupled to the power lines of the dynamoelectric machine along with an oscillator for injecting a selected frequency signal in the line and a detector for detecting the signal when the tuned circuits are resonant. A thermally responsive switch comprising an electromechanical bimetal switch or a solid state PTC or NTC switch is adapted to be disposed in heat conductive relation with the dynamoelectric machine and is electrically coupled to one of the tuned circuits so that the temperatures below a selected level the switch will be in one state, e.g. a low impedance state, precluding resonance while at temperatures above the selected level the switch will be in an opposite state, e.g. a high impedance state, permitting resonance. A detector particularly useful for detecting the above-mentioned signal is shown to comprise a three legged E-I transformer core on one leg of which is disposed a shunt winding. The shunt winding is coupled to a frequency selective device such as a capacitor. A sensing winding is disposed on the center leg and a power supply line is trained through the core so that it forms two turns and causes opposing flux in the center leg of the transformer.
REFERENCES:
patent: 2394786 (1946-02-01), Korneke
patent: 2441967 (1948-05-01), Haug
patent: 2991397 (1961-07-01), Place
patent: 3072827 (1963-01-01), Benish
patent: 3210607 (1965-10-01), Flanagan
patent: 3358208 (1967-12-01), Takami
patent: 3436692 (1969-04-01), Walters
patent: 3588595 (1971-06-01), Silvers
patent: 3946279 (1976-03-01), Paice et al.
Haug John A.
McAndrews James P.
Miller J D
Salce Patrick R.
Texas Instruments Incorporated
LandOfFree
Detector apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Detector apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detector apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2079860