Dimmable high power factor high-efficiency electronic ballast controller integrated circuit with automatic ambient over-temperature shutdown
US5315214A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1992 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Jun 10, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An embodiment of the present invention is a dimmable, high power factor, high efficiency electronic ballast comprising, on a single integrated circuit chip, a shunt regulator, a voltage reference, a high-temperature shutdown, an undervoltage lockout, a timer for start-up and restarting, a variable oscillator, a mode control, an op-amp for receiving a signal proportional to lamp current and for controlling the variable oscillator or the duty-cycle of pulses output in a closed-loop servo, and active power factor correction including an analog multiplier for receiving an AC voltage and an AC current sample, and for multiplying these together to result in a comparison with a DC voltage. The comparison produces a control signal for a MOSFET switch on a boost converter transformer that actively corrects the power factor at a rate set by the oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.