Partial List of Representative Patents Awarded to F.
 Patent 3,040,270
Rectifier Circuit including a Variable Frequency Oscillator”
 Patent 3,222,583
This circuit has been used and continues
to be used for controlling the speed of universal motors in millions of
appliances, hand tools, and sewing machines throughout the world.
 Patent 3,275,909
This is the basic patent for the TRIAC AC
switch used worldwide in almost every lamp dimmer, static AC switch, and
electric heating control.
 Patent 3,404,327
Comprising SCRs with Gate Control Arrangements”.
This circuit patent is basic to at least
a half of all SCRs used in the world.
It covers the use of SCRs in phase control circuits, the basis of
industrial motor drives of all horsepower ratings, battery chargers, and
 Patent 3,535,615
“Power Control Circuits
including a Bidirectional Current Conducting Semiconductor”.
The patent covers basic circuits using
the TRIAC switch. All lamp dimmers
and static AC relays are covered by this patent.
For additional material on
patents  and  above, use this link:
To Gutzwiller Oral History, Page 13