Thanks. As one of the other posters have noted, the specifications are pretty loose, in that most (like the one from On Semi) state that hfe varies between 20 - 70, and at hfe of 70, the collector current is 4.0 A, which is not very helpful. What you have said, is however a lot more concrete.
I fully agree.
** You are fully a f****it and a troll.
Learn to write English properly or else F*CK OFF !!!!
.... Phil
** OK so you CANNOT read English either.
You are quite wrong and you have no comprehension of the topic.
F*ck off.
..... Phil
There is a term called "forced beta", which is the actual ratio of Ic/Ib used by design in a switching application. (Again, I assume we're talking about switching... are we?) If the transistor has a minimum datasheet HFE of 20 at 2 amps, we might decide to force Ic/10, namely 200 mA, into the base to turn it on hard and get the collector saturation voltage nice and low. That would be a forced beta of 10.
I haven't used a 2N3055, or any big power bipolar, in a decade or two. Mosfets are easier to use.
Don't you have a broken casette player or something to fix?
Phil is a perfect example of english etiquette, he's got the colorful metaphors of english down pat!
Jamie
That would be an 8 track!
Jamie
Some of those big old Moto parts had a lot of leakage currents, so the actual HFE might be less than apparent. Some of the darlingtons were especially bad.
"John Larkin" "Phil Allison"
** The tester I used then applied a 1uA current to the base while monitoring the collector current with a 1mA meter, DC supply was from a 9 battery. There was simply no meter deflection until the base current was applied via a push button switch.The particular unit was intended for SS transistors any generally gave low and misleading readings for TO3 devices and no reading at all for TV horizontal output transistors. So I designed a simple tester to cover TO3s where the user adjusted the base current so Ic became 0.5 amps and read the Hfe value from a scale around a pot. The correct test condition was indicated by getting two red LEDs to go out.
One could also test the Vbe by reading the B-E drop at the same time - important for good current sharing in parallel BJT output stages.
... Phil
You keep discussing your two favorite subjects! Obsessions, actually.
Yuk.
--
John Larkin Highland Technology Inc
Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
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