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US4197532A Expired / Lapsed US ⏱️ 0.0 years remaining

Electronic motor fault detector means

Assignee: Honeywell Inc
•
Filing: 1978-04-27
•
Granted: 1980-04-08
•
Expires: 1998-04-27
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Abstract

Abstract The voltage that occurs across the run capacitor of a permanently split capacitor type motor when the motor is in operation is quite high compared to the voltage that is present if the motor is stalled. These different voltage conditions are sensed through the use of a voltage pickoff to control an optical type isolation circuit which in turn controls a switch means to energize a fault indicator.

Inventors

  • 👤 II Phillip N. Lawson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 20:55
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 249 words
A fault detector means adapted to be connected to a capacitor which is used to start an electric motor having a run winding and a start winding, including: voltage pickoff means adapted to be connected to said capacitor to detect a voltage across said capacitor; said pickoff means including stepdown transformer means with a high voltage primary winding adapted to be connected across said capacitor, and low voltage secondary means having adjustable output means; voltage breakdown means connected to said adjustable output means and to light generating means to provide said light generating means with an operating threshold defined by said voltage breakdown means; said light generating means providing a light output whenever said capacitor has a high voltage wherein said threshold is exceeded thereby indicating that said motor has an energizing potential applied thereto and that said motor is rotating; light responsive circuit means including a light responsive resistor responding to said light generating means but electrically isolated from said light generating means; said resistor having a high resistance when light is absent and having a low resistance when light is present; electrically energizable control means for said motor; and indicator means connected to said light responsive circuit means and energized concurrently with said electrically energizable control means; said indicator means indicating a fault condition when said electrically energizable control means calls for said motor to be energized and said light generating means has no light output thereby causing said light responsive resistor to have said high resistance.
Claim 2
Dependent Claim 249 words
A fault detector means adapted to be connected to a capacitor which is used to start an electric motor having a run winding and a start winding, including: voltage pickoff means adapted to be connected to said capacitor to detect a voltage across said capacitor; said pickoff means including stepdown transformer means with a high voltage primary winding adapted to be connected across said capacitor, and low voltage secondary means having adjustable output means; voltage breakdown means connected to said adjustable output means and to light generating means to provide said light generating means with an operating threshold defined by said voltage breakdown means; said light generating means providing a light output whenever said capacitor has a high voltage wherein said threshold is exceeded thereby indicating that said motor has an energizing potential applied thereto and that said motor is rotating; light responsive circuit means including a light responsive resistor responding to said light generating means but electrically isolated from said light generating means; said resistor having a high resistance when light is absent and having a low resistance when light is present; electrically energizable control means for said motor; and indicator means connected to said light responsive circuit means and energized concurrently with said electrically energizable control means; said indicator means indicating a fault condition when said electrically energizable control means calls for said motor to be energized and said light generating means has no light output thereby causing said light responsive resistor to have said high resistance.
Claim 3
Dependent Claim 37 words
A fault detector means as described in claim 1 wherein said light responsive circuit means includes a gated solid state switch with said light responsive resistor connected to control a voltage at a gate of said switch.
Claim 4
Dependent Claim 21 words
A fault detector means as described in claim 2 wherein said voltage pickoff adjustable output means includes an adjustable voltage divider.

References Cited (Backward Citations)

US3321754A Cited
US3334342A Cited
US3505663A Cited
US3427507A Cited
US3611036A Cited
US3794989A Cited
US3820099A Cited
US3854089A Cited
US3950675A Cited
US4040117A Cited
US4027204A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-04-08 1983-10-08 1984-04-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-04-08 1987-10-08 1988-04-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-04-08 1991-10-08 1992-04-08 $7700.00 Window Closed / Lapsed

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