EARLY POWER SEMICONDUCTOR HISTORY AT GE An Interview with F.W. “Bill” Gutzwiller The Early History of the Silicon Controlled Rectifier
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The first SCRs used the case style shown to the right, which has been standardized as a TO-48 case style. The original prototypes used by Bill Gutzwiller for his pioneering applications development used this case style and were labeled as type ZJ-39A. The “ZJ” numbering format was used by GE to identify prototype devices. Production units were available in 1959, in a variety of case styles, performance characteristics and model numbers. The photo above is from the SCR text [10] co-authored by Bill and illustrates the broad range of SCRs available in the early 1960s. The original ZJ-39A was commercialized as the C-35, a sample of which is shown to the right. (This device is approx 1.5” from the top of the large solder lug to the bottom of the mounting bolt). ______________
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