Electricity: motive power systems – Induction motor systems – Primary circuit control
Patent
1978-07-12
1980-04-29
Rubinson, Gene Z.
Electricity: motive power systems
Induction motor systems
Primary circuit control
361 30, 361 33, H02P 144
Patent
active
042008298
ABSTRACT:
A circuit for protecting single phase induction motors of the type having a start winding connected in series with a start/run capacitor. The circuit contains a resistance bridge wherein the motor start winding forms one leg thereof. A d.c. signal is applied to the input terminals of the bridge. A filter is connected to the output terminals of the bridge so that a relatively ripple free d.c. output signal from the bridge can be applied to the positive input terminal of a d.c. comparator, the negative terminal of which is connected to d.c. reference ground. A reference resistor in a leg of the bridge adjacent the start winding is selected so that the bridge is unbalanced to present a positive d.c. signal to a terminal of the comparator so long as the resistance value of the start winding is less than the value of the reference resistor. An excessive temperature increase of the start winding raises its resistance to equal that of the reference resistor to cause the bridge to balance when the temperature of the start winding reaches a predetermined maximum value, whereupon the comparator switches from a conductive to a non-conductive state. An SCR connected to the comparator output controls the operation of a motor-protecting relay to disengage the motor from its driving source when the bridge becomes balanced and when the comparator switches from one output state to another. A re-start button connected across the SCR permits re-start of the motor after it has been disengaged from its driving source by operation of the comparator.
REFERENCES:
patent: 2912644 (1959-11-01), Makous
patent: 3329869 (1967-07-01), Obenhaus
patent: 3913342 (1975-10-01), Barry
patent: 3959692 (1976-05-01), Wetzel
patent: 3974430 (1976-08-01), Tyler et al.
patent: 4044288 (1977-08-01), Godfrey
patent: 4100468 (1978-11-01), Slocum
General Electric Company
Giacalone Frank P.
Reams Radford M.
Rubinson Gene Z.
LandOfFree
Circuit for protecting induction motors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Circuit for protecting induction motors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circuit for protecting induction motors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1685355