United States Patent  [ii] Patent Number: 4,584,488
Towers et al.  Date of Patent: Apr. 22, 1986
FOREIGN PATENT DOCUMENTS
0090294 10/1983 European Pat. Off. 180/142
0141970 8/1983 Japan 180/142
1379606 1/1975 United Kingdom 180/141
1435968 5/1976 United Kingdom 180/142
2119326 11/1983 United Kingdom 180/141
Primary Examiner—William M. Shoop, Jr.
Assistant Examiner—Shik Luen Paul Ip
Attorney, Agent, or Firm—James Ignatowski; Russel C.
An electronic controller for generating a pair of mutually exclusive pulse train signals. The controller having an offset generator for biasing the input signal about a midpoint value, a first and second difference amplifier for generating a first and second difference signal, one difference signal corresponding to the difference between the biased input signal and the midpoint value and the other difference signal corresponding to the inverted difference between the biased input signal and the midpoint value, a saw tooth wave generator generating a saw tooth wave having its valleys clipped to a predetermined value, and a pair of comparators, one generating a pulse train signal in response to the saw tooth wave and the first difference signal and the other generating the second pulse train signal in response to the saw tooth wave and the second difference signal.
17 Claims, 13 Drawing Figures