the high voltage pulse generator

I don't even have a gun any more. They don't work on 0603 parts. Metcal+Mantis works for surface mount.

I do use a pretty big wedge tip for everything.

Yesterday I had to replace four D2PAKs soldered to copper pours. The Metcal did that nicely.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Thanks John, but I think you just posted the wrong file.

--
 Thanks, 
    - Win

This is it, maybe.

15 volts was just a little low for the IR2213 bootstrap circuit.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

I bought my first soldering gun around age 15. Still have it, a very slick design, like a gigantic pencil with a long "linear actuator style" transformer. Then I started using Weller stations and I really like those.

A few years ago I re-learned the advantage of guns now that there is the powerful Weller 100/140W gun. That is almost the first order of business when arriving at a client with EMC issues, having lunch near a HW store and buying a Weller soldering gun there. Or I buy one for them on the way from the airport. Those things heat up fast and can solder thin sheet metal with ease and also big fat ground connections.

--
Regards, Joerg 

http://www.analogconsultants.com/

The D550? They've made that since forever. I have one too, also for shields.

Back in my satcom days I used to use a 120W Weller iron for that--it was shared between about five of us, and its nickname was (inevitably) Godzilla.

Cheers

Phil Hobbs

The 8200 at half that power:

So far it was easy to pick one up for $30-40 and they always had them at the stores.

I have an Ersa 150W big iron in the drawer here, lost of thermal mass so it easily solders really heavy stuff.

Then I have grandpa's "copper hammers" on a stick, with wooden handles. But for those I have to build a fire in the Weber barbecue. Which I do a lot anyhow because that is my favorite way of cooking. Like yesterday, loaded in the wood, lit it, watched it while fixing the disc brakes on my mountain bike, let the wood burn down to coals, baked a bread and afterwards pizza.

--
Regards, Joerg 

http://www.analogconsultants.com/

Probably Vgs max got exceeded via "Miller", then FET briefly shunted and that put a lot of volts across R105 (and thus U9).

The 2SK4177 looks scary. Up to 1400V and less than 2mm spacing between pin 2 and the others. Yikes.

--
Regards, Joerg 

http://www.analogconsultants.com/

I gave away my Metcals when I saw the new Weller WX2 station and associated irons.

Hopefully they last. Their digital ones from the 90's died like flies in my cases. Went back to analog-only and those last.

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Regards, Joerg 

http://www.analogconsultants.com/

We have a bunch of them (probably about even number of Metcal and Wellers, now). AFAIK, none have died (a few Metcals have but they tend to be older). Sure, tips are expendables but Metcals are no different. Everyone at my CPOE is pretty much free to buy what they want and I haven't seen a new Metcal for a couple of years and they're about twice the price.

I've never really warmed up to the Metcals. Mostly because I found the prices exorbitant. Probably one has to pay for the fancy design work and to me solder gear is just tools, it doesn't need to be fancy.

Also, tip prices matter to me. Especially since the advent of this dreaded lead-free solder they wear out faster.

--
Regards, Joerg 

http://www.analogconsultants.com/

I take it back, I was just confused.

--
 Thanks, 
    - Win

In the grand scheme of things, the cost of this stuff is in the noise.

It sure is but all that noise tends to add up. The other advantage with Weller is that you can quickly get them almost everywhere.

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Regards, Joerg 

http://www.analogconsultants.com/

Yeah, it's rated for 1500. On the surface of the D2PAK, the drain-source surface creepage distance is 50 mils, which works out to

30 volts/mil. But I'm only applying 1400! Why did they include the pin 2 stub?

I was assuming a conservative 8 volts/mil surface creepage limit, but a lot of the components have tiny gaps for their rated voltage. The IR2213 pcb footprint allows 75 mils total between-pin gap for 1200 volts. ACPL227 has a 150 mil layout gap that's rated for 3000 volts RMS, which is 28 volts/mil.

Well, so far it works.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

No, I was confused before you were confused.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

No idea, it makes no sense. Probably because it's too cumbersome to change production equipment to trim that off so it disappears inside (which would be the right thing to do here).

I have staggered transistors so each won't have to cope with more than

350V. I like to keep a 30% headroom as margin where possible. One part, a socket that was prescribed and thus outside my jurisdiction, was too iffy for my taste on two contacts so I had the circuit board slotted there.

--
Regards, Joerg 

http://www.analogconsultants.com/

I can't think of anything I'd choose a gun over an iron for. Even a wooden soldering iron with scrap brass or a nail for a tip beats those Weller guns IMHO.

NT

Show us your board!

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics