On Mon, 18 Nov 2013 13:49:57 -0800, John Larkin
wrote:
On Mon, 18 Nov 2013 14:25:27 -0700, Jim Thompson
wrote:
On Mon, 18 Nov 2013 13:20:14 -0800, John Larkin
wrote:
On Mon, 18 Nov 2013 12:25:28 -0700, Jim Thompson
wrote:
On Mon, 18 Nov 2013 10:30:05 -0800, John Larkin
wrote:
On Mon, 18 Nov 2013 11:14:39 -0700, Jim Thompson
wrote:
On Mon, 18 Nov 2013 09:34:16 -0800, John Larkin
m wrote:
On Mon, 18 Nov 2013 09:05:54 -0700, Jim Thompson
wrote:
On Mon, 18 Nov 2013 06:59:03 -0800, John Larkin
m wrote:
On Thu, 14 Nov 2013 08:13:54 -0700, Jim Thompson
wrote:
On Wed, 13 Nov 2013 19:30:07 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART. com wrote:
On Mon, 11 Nov 2013 10:49:05 -0600, "Tim Williams"
wrote:
Is J2 the socket for the PIC, or is it going through cables to the PIC
somewhere else?
What are the trace lengths on the loop from Q1 source (ground), to the
nearest bypass capacitor on +12VR, through D5, back to Q1? (Hint: D5 must
be placed at Q1, not at the coil.)
Why? It will clamp a flyback overshoot wherever it is in the circuit.
If the wiring from FET to coil is significantly inductive, then what?
...Jim Thompson
Since you can't think this through, you'll have to Spice it.
No. It's _you_ who'll have to LTspice it... and you'll get it wrong
:-}
...Jim Thompson
Whenever "Thompson" and "inductance" show up in the same post, amusement is sure
to follow.
Wiring inductance _between_device_and_catch_diode_ can cause voltage
spikes, depending on device turn-off speed... irrespective of what
smug-ass comments Larkin may churn up.
...Jim Thompson
Show us.
See attachment. Sorry that Larkin is incapable of understanding the
basic behavior of _any_ inductance.
...Jim Thompson
Moron. A PCB trace, or a wire, isn't an inductor, it's a transmission
line. And a mosfet isn't an ideal switch.
According to your model, every mosfet always blows up from its own
wirebond inductance! Or from any drain trace, even if the load is
resistive!
(Thompson + inductors) dependably = (stupidity)
No amount of bloviation will cover your ignorance... wiring out to a
solenoid or relay before the catch diode will give you grief.
No matter how many times you bloviate.
...Jim Thompson
Using your idiotic simulation, I suppose so. Good thing I don't use
your idiotic simulations.
25 kilovolts! Hilarious! I wish I could make a 25 kilovolt boost
conveter from a 2N7000!
It was to make my point... after all I did say, "Wiring inductance
_between_device_and_catch_diode_ can cause voltage spikes, depending
on device TURN-OFF SPEED... "
Slower times and less inductance will, of course, produce a smaller
spike... but there WILL STILL BE A SPIKE. And CDG of a power FET will
help slow things down... perhaps enough that the dwell time in the
gate charge plateau region will slowly kill you instead.
Sometimes I feel sorry for you, being manic-depressive has got to be a
burden on an otherwise (allegedly) productive person.
But then that other part of your personality springs forth, you know
the part I mean, the PLUPERFECT ASSHOLE SIDE. Then I lose my
sympathy, and rank you right up there in that class of pompous
ignorance alongside Phil Allison and Bill Slowman.
...Jim Thompson
--
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