Bridge motor driver with short-circuit protection and motor-current limiting feature
US5457364A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1994 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Jan 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H9/002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A full-wave bridge driver has four driver transistors. A motor is connected to the output terminals of the bridge. A fault detector latches off the four driver transistors when the bridge current jumps essentially instantaneously to exceed a predetermined safe-peak value due to a fault occurring in the bridge. A comparator has a predetermined current threshold, that is less than the predetermined safe-peak value of the fault detector, and is connected to a bridge-current sensing resistor for, when the bridge current exceeds the current threshold, producing a signal proportional to the difference between the bridge current and the current threshold. A pulse-width-modulator is connected to the comparator means output, and during periods such as at motor starting when the bridge current gradually exceeds the comparator threshold value, chops the signal at the bases of the four driver transistors, varying the chopped pulse widths to hold the motor current at essentially the threshold current value. For faults that occur across the motor or between the motor and either of the DC-supply terminals, the fault current paths in the bridge do not flow through the inductance of the motor and p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.