Transistor Museum Early Germanium Power Transistor History by Joe Knight Delco Page 2

A SURVEY OF EARLY POWER TRANSISTORS

by Joe Knight

DELCO 1950/1960s GERMANIUM POWER TRANSISTORS

In mid-1957, Delco came out with their first TO-3 device, the 2N392. By the end of 1957, Delco had released 3 more TO-6 Germanium types, the 2N441, the 2N442, and the 2N443, far left. In 1958 they came out with another TO-3 device, the 2N553, the middle two items. In 1958 Delco finally came out with a Silicon 'DS' series of output transistors, one being the TO-6 type "DS-501", far right. All silicon devices apparently came out with red ID tags or were red in color, as in the later 'DTS' 400 volt (!!) series. Another noteworthy Delco device was the "251M-1", a special tested 2N174 item made for the Minuteman missile, this in 1960.

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Joe Knight Early Power Transistor History – DELCO Page 2