The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 1995
Filed:
Jul. 26, 1994
Thomas Ribarich, Glarus, CH;
Knobel AG Lichttechnische Komponenten, Ennenda, CH;
Abstract
A device for protecting a ballast circuit from excess voltage and excess current includes a switch for disconnecting the ballast circuit from the power source and a control circuit for operating this switch; the control circuit monitoring a control point, from which control point a first resistor connects to a first terminal of the power source, a second resistor connects to a second terminal of the power source, and a third resistor connects to a point between the switch and the ballast, the switch being brought into off-state when the voltage between the control point and the first terminal of the power source exceeds a given value, thus leading to a hysteresis between an input voltage for switching the device off and an input voltage for switching the device back on again, with positive feedback being provided by the third resistor for decreasing the switch-off time and the corresponding switching losses.