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Old 15th January 2013, 06:43 PM   #1
clm811 is offline clm811  United States
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Default Question about "matched" power transistors

I recently bought some matched pairs of "Genuine" MJL4281A/4302 off eBay. They are identical to some samples I got from ON Semi, so are prob'ly not fakes.

The seller says he used "curve tracer" and "300mA", but that was all he gave.

Each transistor of the pairs had numbers written on them:

The 4281's were marked "136.1 and "136.3"

The 4302's were marked "184.2" and "184.6 "

I'm new to the realm of curve tracers, so I'm not sure what the markings are(Beta?).

Can anybody here tell me? (The seller's english isn't very good).

Thanks,

-Chas
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Old 15th January 2013, 07:15 PM   #2
effebi is offline effebi  Italy
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I do not have a crystall ball, but it looks like it is Beta (or hfe) measured at 300 mA collector current.
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Old 15th January 2013, 07:34 PM   #3
sreten is offline sreten  United Kingdom
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Hi, that sounds right, given the information, rgds, sreten.

Like types are matched for current sharing, not across types.
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Last edited by sreten; 15th January 2013 at 07:37 PM.
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