Multiplexed temperature sensing circuit for HID lamp ballast
US7333313B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2006 |
| Grant date | Feb 19, 2008 |
| Priority date | — |
| Expiry date | Jun 8, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A temperature sensing circuit for a ballast for a HID lamp multiplexes the temperature measurement function with another function to reduce the number of pins required for the temperature measurement function performed by the microcontroller of the ballast. The circuit includes a microcontroller having a first A/D input/output pin, a second A/D input/output pin and a multifunction pin, a temperature measurement circuit connected to the second A/D pin, a timing circuit connected to the first A/D pin, and a switch connected to the multifunction pin, temperature measurement circuit and timing circuit. The switch activates the temperature measurement function by connecting the temperature measurement circuit to the multifunction pin in a first position and deactivates the function by disconnecting the temperature measurement circuit from the multifunction pin in a second position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.