LT Spice question

Why are there no wooden deck posts that don't rot? Why doesn't Home Depot sell stainless steel deck posts?

All Spice tells lies. A VCVS opamp works fine in situations where you know it works fine.

Sounds like a ton of parts. All I really need is a better opamp. One of the VFB fast fet opamps, like an ADA4817 maybe. I'd have to change the PCB layout for that. Expensive, too.

John

Those Zetex avalanche transistors are very repeatable and avalanche hard, pretty much shorting out like an SCR when they fire. But they are slow, with nanosecond edges, not picoseconds.

Using a SOT23 transistor to make 12 kilowatt pulses is pretty impressive.

I usually trigger them, rather than waiting for them to fire on their own. That way, you get very repeatable pulses. Just a little blip on the base will do it. Jitter is very low.

I was told they are made in Russia. Good avalanche transistors seem to come out of ancient diffused-junction processes. Modern epitaxial parts don't avalanche usefully.

Why model this, when you can measure them?

John

They do, but the injected stuff rots screws and can poison animals if they lick or crunch it. Small children are a concern as well.

Touch to drill. Aluminum would be cheaper and good enough. There is a large market but they fail to see it. Galvanized works well, too, it an last decades.

And you can switch 5kV with a 2N7002 because SPICE doesn't have a

I've had an app recently where I was in a similar pickle. The only real good option was to accept a fixed gain of 5 and use the 12GHz rocket amps from TI. That did the trick.

External resistor just don't work well anymore at those speeds, too much ringing.

I posted a sim of a 1N4148 running happily at 100KV reverse bias.

It helps some to keep the feedback path very tight and cut out any planes below the stuff on the inverting node. But those fixed-gain TI things are the cat's pajamas.

Or use a 99 cent darlington MMIC, if conditions allow. They are dead stable and work fine wideband/time domain.

John

Or, more often, through to hundreds of customers, who each trip over the same bug at great expense. And the parts or datasheets aren't fixed for years or decades.

We need an ICBUGS.COM web site, where we post the gotchas we find. Except the name is already claimed.

John

How about icbloopers.com, icgoofs.com or cattywompuschips.com?

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We should call it 'joergwazhere.org' ;-)

to

chipbugs.com is available.

Cheers

Phil Hobbs

(Who just let three of his domain names lapse)

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for some reason diodes and mosfets in ltspice doesn't have the parameter bv set.

try this:

Version 4 SHEET 1 880 680 WIRE 112 32 48 32 WIRE 256 32 192 32 WIRE 48 80 48 32 WIRE 256 80 256 32 WIRE 256 160 256 144 FLAG 48 160 0 FLAG 256 160 0 SYMBOL voltage 48 64 R0 WINDOW 3 -266 54 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value SINE(0 150 1 0 0 0 1) SYMBOL diode 272 144 R180 WINDOW 0 24 72 Left 0 WINDOW 3 -196 32 Left 0 SYMATTR InstName D1 SYMATTR Value MMSD4148_bv SYMBOL res 208 16 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R1 SYMATTR Value 1k TEXT 304 152 Left 0 !.model mmsd4148_bv ako: mmsd4148 bv=3D100 TEXT -218 -4 Left 0 !.tran .5

-Lasse

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kablouie.com and kablam.com are also still vacant :-)

Nah, that stuff's been gone for a decade or two. The newer stuff isn't as good but isn't nearly as toxic (not that the AS stuff was anyway). If you use sheetrock screws, sure they'll rot off. OTOH, if you use lumber rated for

Aluminum would be enough of a PITA. Just use decent lumber and it'll probably outlast Kalifornica. ;-)

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phut.com

A talent for blowing up parts, like yours deserves to be recognized. :-)

;-)

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So If I register electrooptical.net, how much will you pay me to get it back?

John

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Nice. But that wasn't one of them. I like to use private domains with one catchall mail account that funnels all mail going to that domain into a single account elsewhere. That way I can give out unique email addresses to all those websites that insist on that, and then when one of those addresses shows up in a bit of spam, I know who sold it to them.

Cheers

Phil Hobbs

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It does; try .MODEL DMOD1 D (BV=100) or equivalent.

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Give him a salmon for the net..

You don't need many domains for that. Give them hobbs123@, ... hobbs124@..., hobbs125@, and so on. On my site I can pipe all emails into one bucket. Should one go rogue on me I can dump it and the sender will get an undeliverable message.

Should they be clever and auto-extract your real email via the domain use electrohobbstical.com or something for the "disposable" email accounts and auto-forward from there.

I've been doing it for a decade or so--I register using things like snipped-for-privacy@somejunkdomain.com. Works great.

Cheers

Phil Hobbs