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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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19th Oct 2021, 4:29 pm | #21 |
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Re: 2N 3055-2 ( yes -2 )
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19th Oct 2021, 4:53 pm | #22 |
Octode
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Re: 2N 3055-2 ( yes -2 )
Glad it finally worked, not had that issue previously, so I must remember for any future scans of that type of data. Normal photos seem to work OK, even when I resize before uploading.
Back to the 2N3055, I hadn't looked at the Towers book for a while and totally forgot that there were so many variants, hopefully the scan will help others in finding the correct version or equivalent type for their job in hand. Dave
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19th Oct 2021, 4:53 pm | #23 |
Heptode
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Re: 2N 3055-2 ( yes -2 )
The E stands for the method used to produce the semiconductor die, Epitaxial.
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19th Oct 2021, 5:25 pm | #24 | |
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Re: 2N 3055-2 ( yes -2 )
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19th Oct 2021, 5:29 pm | #25 | ||
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Re: 2N 3055-2 ( yes -2 )
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19th Oct 2021, 5:36 pm | #26 | |
Octode
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Re: 2N 3055-2 ( yes -2 )
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19th Oct 2021, 6:28 pm | #27 |
Heptode
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Re: 2N 3055-2 ( yes -2 )
Unlikely that any recent production 2N3055s are even 2N3055s, I have a linear power supply that uses RCA pass transistors that are 1980's production by their date codes, and are 2N3055H (Homotaxial).
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19th Oct 2021, 6:52 pm | #28 |
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Re: 2N 3055-2 ( yes -2 )
I was under the impression that RCA 'homotaxial' production ceased in the early to mid '70's at the latest, and that the 'H' referred to 'heavy duty' ?
Alan |
19th Oct 2021, 7:07 pm | #29 |
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Re: 2N 3055-2 ( yes -2 )
My 751.1 has STC branded 3055s with '82 date codes and no suffixes. (Probably the American "Silicon Transistor Corporation")
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19th Oct 2021, 7:40 pm | #30 | |
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Re: 2N 3055-2 ( yes -2 )
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19th Oct 2021, 8:08 pm | #31 | |
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Re: 2N 3055-2 ( yes -2 )
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19th Oct 2021, 8:30 pm | #32 |
Hexode
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Re: 2N 3055-2 ( yes -2 )
Amps are remarkably flexible about transistors, so you can usually put an MJ15003 in place of 2N3055 with no problem. But the MJ15003 is a 20 amp part rated at 140v. The 2N3055 is a 15 amp part rated at 60v, though some may carry a higher voltage rating or at least be selected for it. So you cannot put 2N3055 in place of MJ15003 in most places.
Other than maybe some REALLY old first designs, I don;t recall 2N3055s in Peavey amps. I know they used them early on, but I don;t recall in what. MJ15003 was the workhorse of PV amp for a long time.
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Any tool can be used as a hammer but a screwdriver makes the best chisel Last edited by nutteronthebus; 19th Oct 2021 at 8:30 pm. Reason: spelling |
19th Oct 2021, 9:48 pm | #33 |
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Re: 2N 3055-2 ( yes -2 )
There are plenty of fakes around, had some conduct about 500mA max. Cut the top off of one, the die was about 3mm square as opposed to about 7mm for a genuine one!!!
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20th Oct 2021, 1:22 pm | #34 | |
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Re: 2N 3055-2 ( yes -2 )
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20th Oct 2021, 10:22 pm | #35 |
Nonode
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Re: 2N 3055-2 ( yes -2 )
That's OK, I did work out what was happening, let us know how you get on (and I spent a fair bit of time around those parts as a child).
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20th Oct 2021, 10:42 pm | #36 |
Nonode
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Re: 2N 3055-2 ( yes -2 )
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, |