Current feedback amplifier having trimcircuitry and method for controlling and equalizing stator winding current
US5959417A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A current feedback amplifier (12) is provided for controlling a stator winding phase current in a polyphase stator winding, such as a three-phase stator winding (10), of a polyphase direct current motor. The current amplifier (12) includes a first stage current feedback amplifier C (27) and a second stage current feedback amplifier (100) coupled through a switch (101). The first stage current feedback amplifier C (27) detects a stator winding phase current I.sub.AB flowing through a C-coil (15) of the three-phase stator winding (10) and generates an equalized sense current I.sub.senseT in response that is related to I.sub.AB. The equalized sense current I.sub.senseT is generated using a phase trim FET (31) and an adjustable phase trim FET (32). The second stage current feedback amplifier (100) receives I.sub.senseT from the first stage current feedback amplifier C (27) and generates a control signal. This may be done by comparing I.sub.senseT to an amplitude adjusted reference current I.sub.refT. The amplitude adjusted reference current I.sub.refT is generated using an amplitude trim FET (81) and an adjustable amplitude trim FET (82). The second stage current feedback amplifier (10…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.