6 Apr
2011
6 Apr
'11
7:04 a.m.
Oh, absoluytely. You'll never do anything if you
don't make mistakes,
try out ideas that come to nothign, etc.
'The designer who never blew a chip is a bad designer. He never
designed
anything' :-)
In that case I must be a brilliant audio equipment designer. The number
of transistors that exploded while I was building my stereo in the 70s
was amazing :-)
I even managed to short out a 2N3055, but I had to drop a test lead
connected to its collector on to a 220V terminal on the mains
transformer to succeed :-)
OTOH, that also caused a BFR39 or something to send half its case
flying about 10m across the room...
/Jonas
6 Apr
6 Apr
3:16 p.m.
Oh, absoluytely. You'll never do anything if
you don't make mistakes,
try out ideas that come to nothign, etc.
'The designer who never blew a chip is a bad designer. He never
designed
anything' :-)
In that case I must be a brilliant audio equipment designer. The number of transistors that exploded while I was building my
stereo in the 70s
was amazing :-)
Perhaps I'd metter not mention the time I had a pair of EL34s with the
anode glowing bright orange/yellow. Of coruse I had managed to short out
the grid bias supply...
I even managed to short out a 2N3055, but I had to
drop a test lead
connected to its collector on to a 220V terminal on the mains
transformer to succeed :-)
OTOH, that also caused a BFR39 or something to send half its case
flying about 10m across the room...
Or the time I foolishly diabled the overcurrent trip circuit in a DEC
H754 -15V regualtor block to find out why the output voltage was dropping
to 0. The actuall rason was that the crowbar was tirggerign when it
shouldn't Withoput hte overcurrent trip, I think 4 transistors failed,
the small-signal ones blew themselves apart. Oh yes, and then the fuse
burned out.
Never made _that_ mistake again.
-tony
10:24 p.m.
On 06/04/11 20:16, Tony Duell wrote:
Perhaps I'd metter not mention the time I had a
pair of EL34s with the
anode glowing bright orange/yellow. Of coruse I had managed to short out
the grid bias supply...
Did they still work after you cooked the plates?
One of these days I should hunt down a couple of cheap vacuum tubes and
a book on VT amp design and build an audio amp... just for the hell of it.
I think 4 transistors failed,
the small-signal ones blew themselves apart. Oh yes, and then the fuse
burned out.
Rule 1: the penalty for violating Ohm's Law is electrocution.
Rule 2: a transistor will always blow in order to protect the fuse.
Rule 3: If in doubt, see Rules 1 and 2.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
12 Apr
12 Apr
2:35 p.m.
On 06/04/11 20:16, Tony Duell wrote:
Of course. It's not something I recoment trying, though.
Perhaps I'd metter not mention the time I had
a pair of EL34s with the
anode glowing bright orange/yellow. Of coruse I had managed to short out
the grid bias supply...
Did they still work after you cooked the plates?
One of these days I should hunt down a couple of cheap vacuum tubes and
a book on VT amp design and build an audio amp... just for the hell of it.
I am sure we had a thread on this a few months back...
I think 4 transistors failed,
the small-signal ones blew themselves apart. Oh yes, and then the fuse
burned out.
Rule 1: the penalty for violating Ohm's Law is electrocution.
Rule 2: a transistor will always blow in order to protect the fuse.
4850
days inactive
4856
days old
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ard＠p850ug1.demon.co.uk -
classiccmp＠philpem.me.uk -
jonas＠otter.se