This would be a rectifier that
would not only convert A-C power to D-C power, but would also control the amount
of power from zero to maximum steplessly and efficiently. This would be the solid-state equivalent
of the gas thyratron, the motor-generator set, and the grid-controlled
mercury-arc rectifier tube. Besides
replacing all these devices, a “Silicon Controlled Rectifier”, as I coined
the term, would open up untold new areas of applications in industrial,
military, and consumer markets.
I talked up the “SCR” to the
point where our advanced engineering people started looking for ways to
achieve such a power device. When
scientists at Bell Laboratories published a paper on a PNPN signal diode
device*, Gordon Hall and other physicists in Clyde
recognized that it exhibited characteristics that might achieve what I was
pushing them for. Gordon and his
technicians started playing with various semiconductor processes. In short order they produced a power
version of the PNPN diode, but with a third lead to control the point in
each A-C cycle when the device would switch on. It was the exact functional equivalent of
the gas thyratron tube except without its big glass envelop and its glowing
red filaments and attendant power losses.
To Gutzwiller Oral History, Page 6
* Reference seminal Bell Labs
paper by Moll, Tanenbaum, Goldey and Holonyak, “p-n-p-n Transistor
Switches”, Proc. IRE, Vol. 44, September, 1956.