Digital dimming and flashing circuit for locomotive ditch lights
CA 2125833 A1 · Owner: Livsey, Robert A. · Inventors: Wetzel, Donald C.; Livsey, Robert A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A light is dimmed by pulsing it at a selected duty cycle. By pulsing the light can be dimmed without being turned off completely which reduces wear on the filament. The circuit is designed for flashing a pair of ditch lights on a railroad locomotive. The lights are alternately illuminated at full voltage and dimmed by pulsing. The flashing sequence can be activated when the locomotive is travelling below a selected speed or when the horn is sounded. The duration of the flashing sequence is controlled by a timer. The pulsing circuit can be used to effectively reduce a voltage without voltage dropping resistors.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 14, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 14, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 14, 2016.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.