US5345126A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive temperature coefficient start winding protection
Assignee: Tecumseh Products Co
•
Filing: 1993-10-29
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Granted: 1994-09-06
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Expires: 2013-10-29
Abstract
Abstract A protection circuit for a permanent split capacitor motor includes a positive temperature coefficient (PTC) resistor in series with the auxiliary winding of the motor for protecting the auxiliary winding during normal operation. At a predetermined temperature anomaly due to over-current conditions in the windings, the PTC resistor will sharply increase its resistance to a point wherein no current will pass, effectively open circuiting the auxiliary winding from the power source, thereby protecting the windings from damage. A thermally responsive protector may also be used in conjunction with the PTC resistor for providing further over-current protection to both the main and auxiliary windings.
Inventors
- 👤 Ricky L. Bunch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:17
CPC Classifications
H; H02; H02K; H02K17/00; H02K17/02; H02K17/04; H02K17/08; H02K11/00; H02K11/20; H02K11/25
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
126 words
An over-current protection device for a permanent split capacitor (PSC) motor having an auxiliary winding and a main winding, the auxiliary winding and the main winding connected in parallel, and a run capacitor connected in series with the auxiliary winding, the protection device comprising: a positive temperature coefficient (PTC) element connected in series with the auxiliary winding and in parallel with the main winding, said PTC element having an anomaly temperature that allows start-up current and normal operation current to flow through the auxiliary winding, but which substantially interrupts the current flow in the auxiliary winding when an over-current or fault current condition occurs by an increase in resistance due to a concurrent rise in temperature to effectively open-circuit the auxiliary winding from the current flow.
Claim 2
Dependent Claim
126 words
An over-current protection device for a permanent split capacitor (PSC) motor having an auxiliary winding and a main winding, the auxiliary winding and the main winding connected in parallel, and a run capacitor connected in series with the auxiliary winding, the protection device comprising: a positive temperature coefficient (PTC) element connected in series with the auxiliary winding and in parallel with the main winding, said PTC element having an anomaly temperature that allows start-up current and normal operation current to flow through the auxiliary winding, but which substantially interrupts the current flow in the auxiliary winding when an over-current or fault current condition occurs by an increase in resistance due to a concurrent rise in temperature to effectively open-circuit the auxiliary winding from the current flow.
Claim 3
Dependent Claim
16 words
The protection device of claim 1, wherein said PTC element is disposed internal to said windings.
Claim 4
Dependent Claim
16 words
The protection device of claim 1, wherein said PTC element is disposed external to said windings.
Claim 5
Dependent Claim
29 words
The protection device of claim 1, further comprising a thermal protector for interrupting power to the motor, said thermal protector disposed in series with the main and auxiliary windings.
Claim 6
Dependent Claim
16 words
The protection device of claim 4, wherein said PTC element is integral with said thermal protector.
Claim 7
Dependent Claim
148 words
An over-current protection device for a permanent split capacitor (PSC) motor having an auxiliary winding and a main winding, the auxiliary winding and the main winding connected in parallel, and a run capacitor connected in series with the auxiliary winding, the protection device comprising: a positive temperature coefficient (PTC) element connected in series with the auxiliary winding and in parallel with the main winding; and a thermal protector for interrupting power to the motor, said thermal protector disposed in series with the main and auxiliary windings; said PTC element having an anomaly temperature that allows start-up current and normal operation current to flow through the auxiliary winding, but which substantially interrupts the current flow in the auxiliary winding when an over-current or fault current condition occurs by an increase in resistance due to a concurrent rise in temperature to effectively open-circuit the auxiliary winding from the current flow.
Claim 8
Dependent Claim
148 words
An over-current protection device for a permanent split capacitor (PSC) motor having an auxiliary winding and a main winding, the auxiliary winding and the main winding connected in parallel, and a run capacitor connected in series with the auxiliary winding, the protection device comprising: a positive temperature coefficient (PTC) element connected in series with the auxiliary winding and in parallel with the main winding; and a thermal protector for interrupting power to the motor, said thermal protector disposed in series with the main and auxiliary windings; said PTC element having an anomaly temperature that allows start-up current and normal operation current to flow through the auxiliary winding, but which substantially interrupts the current flow in the auxiliary winding when an over-current or fault current condition occurs by an increase in resistance due to a concurrent rise in temperature to effectively open-circuit the auxiliary winding from the current flow.
Claim 9
Dependent Claim
16 words
The protective device of claim 6, wherein said PTC element is disposed internal to said windings.
Claim 10
Dependent Claim
16 words
The protective device of claim 6, wherein said PTC element is disposed external to said windings.
Claim 11
Dependent Claim
17 words
The protection device of claim 8, wherein said PTC element is integral with said thermally responsive means.
References Cited (Backward Citations)
US4250419A
Cited
US3963962A
Cited
US4084202A
Cited
US3955170A
Cited
US4092573A
Cited
US4086558A
Cited
US4119894A
Cited
US4198669A
Cited
US4161681A
Cited
US4100468A
Cited
US4181393A
Cited
US4408244A
Cited
US4319299A
Cited
US4387330A
Cited
US4422120A
Cited
US4467385A
Cited
US4701824A
Cited
US4890025A
Cited
US5010264A
Cited
US5021915A
Cited
US5053908A
Cited
US5032749A
Cited
US5055726A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-09-05 | 1998-03-07 | 1998-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-05 | 2002-03-07 | 2002-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-05 | 2006-03-07 | 2006-09-06 | $7700.00 | Window Closed / Lapsed |