E
Eeyore
Jan said:Here it is winter with summer temperatures,
It's very mild here too.
I just went out in jeans and T-shirt.
Graham
Jan said:Here it is winter with summer temperatures,
Jim Thompson said:[snip]
What a piece-a-crap.
I've got to get into this audiophool business... looks like all kinds
of dummies sitting there ready for the taking ;-)
...Jim Thompson
Talking shit about politics does not qualify you for talking shit about
electronics.
DNA
Jim Thompson said:[snip]
What a piece-a-crap.
I've got to get into this audiophool business... looks like all kinds
of dummies sitting there ready for the taking ;-)
...Jim Thompson
martin griffith a écrit :
One clicked at random from all the list...
http://pag.csail.mit.edu/~adonovan/dilbert/show.php?day=6&month=2&year=1999
Jim Thompson said:Jim Thompson said:martin griffith wrote:
Ok, this is a classic audio doofer
http://johnhardyco.com/pdf/990.pdf
[snip]
What a piece-a-crap.
I've got to get into this audiophool business... looks like all kinds
of dummies sitting there ready for the taking ;-)
...Jim Thompson
Talking shit about politics does not qualify you for talking shit about
electronics.
DNA
I thought I had already earned the second ?
...Jim Thompson
--
Eeyore said:Actually there is.
Graham
"Fred Bartoli"
What are the chances of that!!!!!!!!????????
Sales Rep.....
Has to roll up his shirt sleeve to take a shit.
DNA
Ban said:That's interesting, where is it?
Eeyore said:CR11,12. If the output current x Remitter exceeds the diode forward
voltage, it clamps the drive. It's not very intuitive though.
Graham
Nope. Bad shot, Graham.
These diodes are there to pull up the base in case of inductive kickback
current. This is better than putting them to the rails, because then the
transistor breaks down with negative Vbe.
If they were for current limiting, they had to be turned around and
doubled(or a red LED) to allow also for the Vbe of the transistor.
Didn't say anything 'cause I waited to see.
The thing is, there's still current limitation.
On Thu, 30 Nov 2006 08:22:14 +0100,
Fred Bartoli wrote
Imax = Ub/3.9. That's a limit.
Actually it's four diode drops / 3.9 Ohms, that's .7 A.
Ban said:Nope. Bad shot, Graham.
These diodes are there to pull up the base in case of inductive kickback
current. This is better than putting them to the rails, because then the
transistor breaks down with negative Vbe.
If they were for current limiting, they had to be turned around and
doubled(or a red LED) to allow also for the Vbe of the transistor.
Robert said:On Thu, 30 Nov 2006 08:22:14 +0100,
Fred Bartoli wrote
Imax = Ub/3.9. That's a limit.
Actually it's four diode drops / 3.9 Ohms, that's .7 A.
Robert Latest a écrit :
Actually it's not four diode drops.
Robert said:On Thu, 30 Nov 2006 09:36:54 +0100,
Fred Bartoli wrote
Right. Vbe counts in the other direction, so it's two drops.
Eeyore said:~ 2 x Vf / Remitter is indeed the current limit.
It's more obvious if you redraw the circuit.
Graham
Ban said:Then how long will it survive an accidental short O/P to V+/- ? That
makes 46.5V *.38A =17.88W dissipation in one transistor. Good luck.
Then how long will it survive an accidental short O/P to V+/- ? That
makes 46.5V *.38A =17.88W dissipation in one transistor. Good luck.
Is the current not also limited by beta x the current drive?
The drive current (bottom transistor) is 0.7 / 110 = 0.6mA.
The beta of the MJE-171 is perhaps about 50, so the I max is 30mA.