Motor protection circuit
US3974430A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1974 |
| Grant date | Aug 10, 1976 |
| Priority date | — |
| Expiry date | Sep 6, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/0852
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor protection circuit employs a resistance bridge circuit with one side having multiple branches containing temperature responsive resistances for sensing an overheat condition in the motor. Semiconductor voltage sensing devices, such as high gain amplifiers, are responsive to voltages between a standard sensing node and each of the sensing nodes in the multiple branched side of the bridge circuit. Logic facilities respond to any of the sensing devices to operate switching facilities controlling energization of the motor. Additionally, the protection circuit may include a lubricating oil pressure responsive control which is not affected by power loss or spurious signals, and which may be controlled by the operation of a motor control switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.