Power supply
CA 1289184 C · Owner: Thorn Emi Plc · Inventors: Scott, Mark Alastair
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Arc discharge lamps driven at frequencies in excess of 20kHz may exhibit the phenomenon of 'acoustic resonance' in which longitudinal and lateral acoustic waves are supported in the arc tube. This is a problem because the acoustic wave may give rise to an instability in the discharge arc causing it to, stretch or gyrate and invariably to extinguish. In some cases damage may be caused to the arc tube. A power supply suitable for an arc discharge lamp (1) comprises a drive circuit (10) arranged to supply voltage to the lamp (1) and control means (20) for causing a characteristic of the voltage to vary, with time, in accordance with a pseudo random sequence in order to reduce, or eliminate …
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
- Granted September 17, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 17, 2008.
- 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.