Phase control ballast
US4580080A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 20, 1983 |
| Grant date | Apr 1, 1986 |
| Priority date | — |
| Expiry date | Oct 20, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A phase control ballast in which a reactor and a triac are connected in series with an hid discharge lamp across an ac voltage source. A supra-linear converter connected to a rectifier-filter provides a reference voltage which is a supra-linear function of the source voltage. A ramp generator provides a ramp voltage climbing at a constant rate. At the instant when the ramp voltage exceeds the level of the reference voltage, a comparator circuit provides a signal to the gate of the triac which turns it on. A triac state detector responds to the turning on of the triac in either polarity by dropping the ramp voltage to zero and holding it at zero until the triac turns itself off.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.