Pulse-width modulated circuit for applying current to a load
US5365422A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1993 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Jun 1, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/53878
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pulse-width modulated (PWM) circuit alternately applies voltage from a power supply across a load, and alternately establishes one or more non-powered, closed paths for freewheeling current. The circuit includes pairs of switches connected to the load and also connected to the power supply. PWM signals derived from a command signal drive the switches in such a manner as to create the freewheeling current paths in a desired pattern and sequence. The circuit effectively reduces ripple current in the load while also substantially reducing the amount of current flowing through the power supply filter capacitor. Thus, the size and rating of the power supply can be reduced. One can use the invention to drive a load in a multiple-phase environment, and also in the context of a three-phase trapezoidal drive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.