Voltage transients
US4879623A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1985 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Dec 2, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Motor control systems having solid-state components are commonly used on industrial vehicles such as lift trucks. Such solid-state components are easily damaged by excessive transient voltages. The subject invention includes a power supply for supplying direct current to a motor circuit, wherein the direct current has a nominal direct current voltage value and as associated transient voltage component. A pulse control circuit supplies current pulses from the power supply to a motor. A sensing device controllably produces a fault signal in response to the amplitude and frequency of occurrence of the transient voltage component exceeding a predetermined maximum value. An override circuit receives the fault signal and responsively modifies the current pulses delivered from the power supply to the associated motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.