Patents by Inventor Dalziel L. Fisher

Dalziel L. Fisher has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5604409
    Abstract: An electronic circuit for converting AC or DC input current to pulsating DC, then to high frequency AC. The DC input is used for aircraft applications, or in emergency situations. The circuit operates over a wide range of input voltages and frequencies, including aircraft 115 volts, 400 Hertz. The circuit has a multivibrator that receives a smooth DC operating potential. The multivibrator is operably connected to a differentiator that produces substantially square waveform outputs. Dual wave shape filters are operably connected to the differentiator to shape the square wave outputs into a sine wave and a cosine wave respectively. A transistor switch is operably connected to each wave shape filter. The circuit has a transformer operably connected between the transistor switches and a load. In a specific embodiment the loads are either hot or cold fluorescent lamps, or the like.
    Type: Grant
    Filed: July 12, 1993
    Date of Patent: February 18, 1997
    Inventor: Dalziel L. Fisher