Motor control circuit for tape drive unit
US4156257A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1977 |
| Grant date | May 22, 1979 |
| Priority date | — |
| Expiry date | Apr 4, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/934
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A tape drive for moving a tape with a prerecorded clock track past a transducer at a constant velocity. An output signal from a speed servo circuit controls the energization, and hence the speed, of a tape driving motor. It responds to a tape speed signal derived in part from a power supply voltage and a speed reference signal derived from the power supply voltage. Voltage variations and temperature-induced variations in the power supply have a minimal effect on tape velocity. Tension servo circuits control the power to a driven motor in response to the speed reference signal and the speed servo output signal thereby to maintain the tape under tension. A brake and park gating circuit slows the tape and maintains the tape under tension when it stops. The speed reference signal undergoes an exponential rise during starting operations to minimize acceleration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.