Transistor Museum Early Germanium Power Transistor History by Joe Knight Honeywell

A SURVEY OF EARLY POWER TRANSISTORS

by Joe Knight

HONEYWELL 1950s GERMANIUM POWER TRANSISTORS

L-TO-R: Honeywell was also an early (first?) developer of Power Tetrode transistors. The first item shown is a developmental power tetrode, likely from 1956, with the leads marked "B1, B2, C and E". By late 1957 Honeywell announced a Power Tetrode called the H200E. In addition, Honeywell developed the first series of RETMA registered power tetrodes, called the 3N45 (second item), 3N46 and 3N47 (third item), released around 1959. These were all designed to operate at much higher frequencies than any other power transistor to date. Finally, in mid-1957 Honeywell announced another larger Germanium device called the XH10 (Experimental?- not shown) which was rated at a higher 10 amps. This was superseded by the H10 in late 1957, which was rated at 15 amps. By early 1958 Honeywell had released a RETMA series of power transistors, similar to the H10, called the 2N574and the 2N575 (last item), and all rated at 25 watts dissipation. These are about 1" in diameter and are similar to the other manufacturers’ TO-3 types then in production.

Note: Often times different transistor listings will show different dissipation and output ratings, dependent usually upon specific temperature criteria. Consequently, one might see numbers other than what I have shown for certain devices. This may explain why.

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Joe Knight Early Power Transistor History – HONEYWELL Page 2