[Synchrodyne]

As a more general observation, the 2N3055 was evidently of sufficient importance to have warranted an IEEE paper on its history, namely:

“The 2N3055: A Case history”; John N. Ellis and Vince S. Osadchy; IEEE 2001.

I don’t think that it is stretching “fair use” too much to quote the abstract and the concluding paragraph from that paper:


Abstract—The 2N3055 power transistor was introduced by the Radio Corporation of America (RCA) in the early 1960s. It was one of the first silicon power transistors, offered unrivaled second breakdown immunity and found many applications particularly in audio power amplifiers and linear power supplies. Other companies tried to copy it with varying degrees of success: one company acknowledges it now by naming a power MOSFET after it. We trace its history, manufacture and eventual decline against pressure from competing technologies. Modern simulation tools have been used to investigate the operation of the device which illustrate its good, and not so good, features. We also relate its geometry to a SPICE model. Neither of these tools would have been available to the original developers. We propose that this transistor be given a place in the archives of history, ranked alongside other famous devices of the 20th century such as the 300B tube.

Concluding paragraph:

The popularity that the 2N3055 had, though, in its day, must surely be noted by the fact that other manufacturers offered similar devices, some with the “3055” name, and PNP complements using the name “2955.” At least one other manufacturer used the term “single diffused,” which had become associated with the high temperature drive-in of the 2N3055. But this claim referred to an emitter drive into an epitaxial base. One manufacturer has since named a power MOSFET after it, copying some of the pertinent device specifications. We believe that this demonstrates the industry’s acknowledgment to perhaps the world’s most popular power transistor of its time, if not in the 20th century


Cheers,