Patents Assigned to Electrotech Instruments Limited
  • Transformers and coupled inductors with optimum interleaving of windings
    Patent number: 5543773
    Abstract: A transformer or coupled inductor with any arbitrary turns ratio (for example, non-integral), and optionally with multiple secondary windings, has primary and secondary windings interleaved on the same winding layer, preferably around a magnetically permeable or an air core. This is capable of giving optimum magnetic coupling, minimum leakage fields and negligible proximity effect losses. The electrical turns ratio is determined by series or parallel, or combination series-parallel, connections of the physical turns of each winding.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: August 6, 1996
    Assignee: Electrotech Instruments Limited
    Inventors: Peter D. Evans, William J. B. Heffernan
  • Switch mode converters
    Patent number: 4353113
    Abstract: A magnetic amplifier which has a main winding and at least one secondary reset winding, and a core composed of amorphous magnetic material, the amplifier being arranged to operate at a frequency greater than 20 KH.sub.z. The invention also includes a switch mode converter which includes such a magnetic amplifier arranged to regulate the output of the converter by pulse width modulation.
    Type: Grant
    Filed: March 20, 1981
    Date of Patent: October 5, 1982
    Assignee: Electrotech Instruments Limited
    Inventor: Keith H. Billings