US4390825A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auto-threshold slow start control circuit for a centrifuge
Assignee: Sorvall Products LP
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Filing: 1981-06-26
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Granted: 1983-06-28
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Expires: 2001-06-26
Abstract
Abstract This invention relates to a slow start control network which includes a field effect transistor triggered by the voltage across a charging capacitor. The field effect transistor permits current flow through a portion of an associated centrifuge drive motor control arrangement. A supplemental charging current source is provided to assist the charging of the capacitor to the triggering signal level within a predetermined short delay time.
Inventors
- 👤 David W. Ginn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:27
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/16; H02P1/24; B; B04; B04B; B04B9/00; B04B9/10; Y; Y10; Y10S; Y10S388/00; Y10S388/923; Y10S388/933
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
110 words
A slow start control network for use with a drive motor control arrangement for a centrifuge comprising: a circuit element having a predetermined transfer function connectable to the drive motor control arrangement; a charging capacitor adapted to apply a predetermined triggering signal to the circuit element to trigger the same and initiate current flow through the drive motor control arrangement; a primary current source for charging the capacitor; a supplemental current source for providing a supplemental current to the capacitor to assist the charging of the capacitor; and means responsive to the flow of current through the drive motor control arrangement to disconnect the supplemental current source from the capacitor.
Claim 2
Dependent Claim
110 words
A slow start control network for use with a drive motor control arrangement for a centrifuge comprising: a circuit element having a predetermined transfer function connectable to the drive motor control arrangement; a charging capacitor adapted to apply a predetermined triggering signal to the circuit element to trigger the same and initiate current flow through the drive motor control arrangement; a primary current source for charging the capacitor; a supplemental current source for providing a supplemental current to the capacitor to assist the charging of the capacitor; and means responsive to the flow of current through the drive motor control arrangement to disconnect the supplemental current source from the capacitor.
Claim 3
Dependent Claim
15 words
The centrifuge according to claim 1 wherein the circuit element has an exponential transfer function.
Claim 4
Dependent Claim
15 words
The centrifuge according to claim 2 wherein the circuit element is a field effect transistor.
Claim 5
Dependent Claim
35 words
The centrifuge of claims 1 or 2 wherein the disconnect means includes a transistor responsive to the flow of control current in the drive motor control arrangement to disconnect the supplemental source from the capacitor.
Claim 6
Dependent Claim
48 words
The centrifuge of claims 1 or 2 wherein the disconnect means includes a first and a second transistor connected as a current mirror and responsive to the flow of control current in the portion of the drive motor speed control to disconnect the supplemental source from the capacitor.
References Cited (Backward Citations)
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Cited
US3970245A
Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-27 | 1986-12-27 | 1987-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-27 | 1990-12-27 | 1991-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-27 | 1994-12-27 | 1995-06-28 | $7700.00 | Window Closed / Lapsed |