Adjustable DC pulse circuit for variation over a predetermined range using two timer networks
US4204141A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 11, 1978 |
| Grant date | May 20, 1980 |
| Priority date | — |
| Expiry date | Sep 11, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/292
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for providing a dc pulse, such as to a gated semiconductor for at least partial bypass of a ballast element connected to an HID lamp, the pulse being developed within a time range of an associated ac voltage. A first timer operably connected to the ac voltage produces a first dc output pulse and a second timer connected to the output of the first timer produces the circuit dc pulse output. Reduction of a threshold control voltage of the first timer permits a time constant network connected thereto to advance the conclusion of the output of the first timer forward within its operational range. A time constant network connected to the second timer has charge current added to it from the first timer control voltage, the amount of such current decreasing with an advance positioning of the output of the first timer, thereby increasing the slope of the charge-up voltage of the second time constant network and shortening of the related square wave or dc pulse output from the second timer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.