Isolator for use with frequency responsive switching circuit
US4392089A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1981 |
| Grant date | Jul 5, 1983 |
| Priority date | — |
| Expiry date | Jul 20, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/392
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A frequency responsive power control system includes an improved isolator in series electrical connection with respect to a ballasted lamp load. The isolator has a high inductive impedance at low current for blocking ballast induced noise signals from interferring with proper operation of frequency responsive switching circuits in the system. In a particularly useful embodiment, the isolator is inductively matched to the capacitive characteristic of the ballasted lamp load so that the isolator-load circuit combination is resonant at a frequency sufficiently removed from any of the control system activation frequencies so as to block any noise signals induced by the ballasted load which might otherwise cause undesired activation of the switching circuits and flickering of the ballasted lamp loads. Under saturation current, with the switching circuit conducting, the isolator functions collectively with the load to provide an impedance which blocks control signals from reaching the load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.