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A SURVEY OF EARLY POWER TRANSISTORS by Joe A. Knight TRANSISTOR PRODUCTS INC 1950s GERMANIUM POWER TRANSISTORS
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My first photo is of the smaller Transistor Products Inc. (TP) power transistors. Clevite bought out Transistor Products in 1954 and so final production items from 1955 onward will have a CT/P decal or marking.
Top Row: L-TO-R: The first one is probably one of those early hand-made experimental versions that Prof. Fletcher made himself of the very first power device ever produced, the X-78, this from mid-1953. The next one is still a TP prototype version of the X-78 (rated at about 2 watts dissipation) but is constructed like the finished version, finally advertised and produced in early 1954. The next one is a TP prototype X-102 (rated at 1/4 watt dissipation), the production version which came out in early/mid 1955. The middle item is a TP developmental device called an X-106 and has a corrugated exterior heat-sink the same height as the body (about 3/8"). The next one, although not marked, is similar in height to the X-106 but has an almost 3/4" high corrugated heat-sink - these two appear to precede the next CT/P production item, the X-107.
Bottom Row: L-TO-R: On the left is a CT/P type X-107 production unit from early/mid 1955 – it was rated at 2 1/4 watts dissipation and has a 3/4" tall corrugated external heat-sink. The final item is another production device, called the CT/P X-125, (rated at 1.2 watts dissipation, and no heat-sink) also released in early/mid 1955. The CT/P “X” production types were apparently somewhat limited in numbers, as so few have survived.
All these shown dissipation ratings came from a June 1955 Transistor Spec Chart.
Go To Transistor Products Inc Early Power Transistors, Page 2
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COPYRIGHT © 2007 by Jack Ward. All Rights Reserved. http://www.transistormuseum.com/ Joe A. Knight Early Power Transistor History – TRANSISTOR PRODUCTS INC |
