Hybrid electrical braking method and system for tool equipment having induction motor drives
US4395670A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 23, 1981 |
| Grant date | Jul 26, 1983 |
| Priority date | — |
| Expiry date | Feb 23, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P3/24
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A hybrid electrical braking method and system are provided for tool equipment having induction motor drives. This hybrid electrical braking can be used to advantage in various types of induction motor driven tool equipment where it is desirable rapidly to stop rotation of the motor rotor and tool, whenever the motor is turned off, for example in food processors of the type having a working bowl mounted on a base containing the induction motor, with tool drive means in the bowl for removably supporting a rotary food processing tool driven by the induction motor. The new electrical braking rapidly halts coasting of the rotor and tool by utilizing in sequence two different electromagnetic braking processes, producing rapid but gentle braking effect after the motor has been turned off. During a first portion of this sequence, the starting capacitor is switched into series with both the "START" and "RUN" windings, thereby producing rapid initial braking action, lasting for approximately 50 milliseconds, slowing the rotor to approximately one-half of normal running speed. As soon as the motor has been slowed, a half-wave rectified D.C. current injected through the RUN winding, producing …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.