Protective load disconnect unit for remote load control systems
US4206443A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1978 |
| Grant date | Jun 3, 1980 |
| Priority date | — |
| Expiry date | Feb 17, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/033
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A protective load disconnect unit is remotely controlled at a single control input terminal from a master controller and monitoring unit. A power switching circuit is actuated to switch a load to be controlled from on to off by a control signal from the master unit. The input terminal is maintained electrically isolated from the switching circuit. A load status response circuit senses the on-off conditions of the power switching circuit. A variable impedance circuit included in the load status response circuit is isolated from the power switching circuit and is connected to the input terminal. The on and off conditions of the power switching circuit changes the variable impedance circuit so that an electrical condition at the input terminal is varied to indicate the load status while the control signal concurrently actuates the switching circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.