Ringing generator
CA 1114536 A · Owner: Mitel Corporation · Inventors: Kiss, William B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A ringing signal supply for supplying ringing current to a telephone line with high efficiency and minimum distortion. As the ringing current demand of a load increases, distortion of the output signal is produced which causes an error signal to be generated after comparison of the output signal waveshape with a reference waveshape. The error signal is used to change the duty cycle of a pulse signal from which the output ringing signal is produced, thereby maintaining the proper output signal waveshape.
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 December 15, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 15, 1998.
- 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.