Soldering bypass caps to QFP possible?

[Joerg]

in the late 90s our machine shop moved across the road (we expanded).
The IT department asked R&D what to do re. ethernet, and was told "fiber
optics". But that cost a few k, so they strung an ethernet cable up on
the power poles, beside the phone lines. About 1km away (across the road
from the company our former R&D mgr and senior engineers set up)
lightning hit a ground-mounted transformer, and made a hell of a mess.
the resulting EMP snotted about a dozen ethernet cards, and fried the
brain operating an old turret-punch that had been upgraded from relay
control to PC control. Ignoring the turret punch, it cost $3k to fix all
the other PCs. The turret punch, being customised about a decade earlier
by nobody knows who, was essentially unfixable. When the IT department
queried R&D they got a great deal of laughter, and "WE TOLD YOU SO".
After this little event, they bought the thousand bucks worth of fiber
optics. I believe the turret punch got sold as scrap. oddly enough,
nobody got fired.

Ouch! Fiber optics isn't that expensive. We even used it inside
buildings for really long runs. Possibly you could have connected it all
up on the cheap with a couple of wireless routers and directional
antennas. Usually a machine shop doesn't need a whole lot of bandwidth.
Wireless also avoids the telco guys wondering "What's this here cable
doing up on the pole?" and then just snipping it off.

 

[Terry Given]

Ouch! Fiber optics isn't that expensive. We even used it inside
buildings for really long runs. Possibly you could have connected it all
up on the cheap with a couple of wireless routers and directional
antennas. Usually a machine shop doesn't need a whole lot of bandwidth.
Wireless also avoids the telco guys wondering "What's this here cable
doing up on the pole?" and then just snipping it off.

I believe that was for a COTS ether-to-fiber system. bear in mind that
here on the arse end of the planet, stuff can be very expensive. A pair
of Levi 501s willset you back NZ$120, and a pair of Dr Martens boots
NZ$250. Which is why I buy my levis when in USA (< US$20), and docs in
the UK (about 40 quid). somebody here is making a LOT of money.

I recently bought a nice Tek 4ch isolated scope & 3 AC current probes,
from a dealer in CA. I had it shipped to a client in SF, and neglected
to tell the dealer I was based in NZ, otherwise they wouldnt have sold
it to me. The NZ tek agent wanted NZ$2500 more than the US retail price
* exhcange rate. thieving weasel!

Cheers
Terry

 

[Joerg]

I believe that was for a COTS ether-to-fiber system. bear in mind that
here on the arse end of the planet, stuff can be very expensive. A pair
of Levi 501s willset you back NZ$120, and a pair of Dr Martens boots
NZ$250. Which is why I buy my levis when in USA (< US$20), and docs in
the UK (about 40 quid). somebody here is making a LOT of money.

I recently bought a nice Tek 4ch isolated scope & 3 AC current probes,
from a dealer in CA. I had it shipped to a client in SF, and neglected
to tell the dealer I was based in NZ, otherwise they wouldnt have sold
it to me. The NZ tek agent wanted NZ$2500 more than the US retail price
* exhcange rate. thieving weasel!

Yep, that's how I did things when in Europe. Paid my import duty, VAT
and all, so it was all legit. But this cut out the hungry middlemen.
Software often had a 100% markup in Europe, probably still does.

For the next scope check out the GW-Instek series. Got their top of the
line here. Handles IMHO better than a comparable Tek, cost >30% less.
Love it. But it is a wee bit larger.

 

[Pintle]

Except that there aren't any vias. The next one is about 1-1/2 inches
away and that's also where the lone bypass cap dwelleth. Ground is
almost as long and takes a different path :-(

Through hole caps, cut & solder the leads to the pins, small amount of
sealant or double stick tape to adhere the body of the cap to the top
of the QFP.

It is slow and painful process but quite doable.

What type of Conformal coating was used? Some can be removed in small
sections with a glass bead airgun.

 

[Terry Given]

Yep, that's how I did things when in Europe. Paid my import duty, VAT
and all, so it was all legit. But this cut out the hungry middlemen.
Software often had a 100% markup in Europe, probably still does.

ditto. the prices I quoted were ex. GST.

For the next scope check out the GW-Instek series. Got their top of the
line here. Handles IMHO better than a comparable Tek, cost >30% less.
Love it. But it is a wee bit larger.

I got the Tek scope because it has 4 independantly isolated channels.
and cost less than 4 P5200 diff probes. when I tossed in the power calc
module it was still less than 4 diff probes

Cheers
Terry

 

[Joel Koltner]

Joerg,

Us consultants often have to pick up the pieces afterwards and try to save
the day :-(

It seems as though that ought to pay pretty well though, no? You're so frugal
I often start thinking you must not have a lot of income, but then you
describe the projects you work on and it's clear you should be making a decent
income! What are you doing with all that income? Saving it? Taking high-end
vacations with your wife? Donating it to charities of your choice?

Just curious...

---Joel

 

[Joel Koltner]

About 1km away (across the road from the company our former R&D mgr and
senior engineers set up) lightning hit a ground-mounted transformer, and
made a hell of a mess. the resulting EMP snotted about a dozen ethernet
cards

I guess an isolation transformer that's all of a couple cm on a side doesn't
hold up real well against, 100kV...

The turret punch, being customised about a decade earlier by nobody knows
who, was essentially unfixable.

That's when you're supposed to find some savvy high-school or college kid,
hire them as an intern for the summer and tell them, "See that machine there?
Make it work again!"

oddly enough, nobody got fired.

It probably would have been impossible to prove just how much less damage
would have been done if the fiber links had already been in place.

 

[Jim Thompson]

Joerg,



It seems as though that ought to pay pretty well though, no? You're so frugal
I often start thinking you must not have a lot of income, but then you
describe the projects you work on and it's clear you should be making a decent
income! What are you doing with all that income? Saving it? Taking high-end
vacations with your wife? Donating it to charities of your choice?

Just curious...

---Joel

Joerg is buying pellets for his stove ;-)

...Jim Thompson

 

[Terry Given]

I guess an isolation transformer that's all of a couple cm on a side doesn't
hold up real well against, 100kV...




That's when you're supposed to find some savvy high-school or college kid,
hire them as an intern for the summer and tell them, "See that machine there?
Make it work again!"




It probably would have been impossible to prove just how much less damage
would have been done if the fiber links had already been in place.

SIMILAR THINGS HAPPENED AFTER THE FIBER LINK - NO DAMAGE. oops, sorry
about shouting

Cheers
Terry

 

[Joel Koltner]

SIMILAR THINGS HAPPENED AFTER THE FIBER LINK - NO DAMAGE. oops, sorry about
shouting

Pretty damning evidence, certainly, but I don't suppose anyone was out for
blood by that point, eh?

 

[Joerg]

Joerg is buying pellets for his stove ;-)

Yes! And when it comes to beer, only the good stuff.

Frugality was taught by my parents and grand-parents. If it can be
fixed, don't throw it away. Keep things simple. Buy only the good stuff
because it'll last. Don't buy a bigger car, TV, whatever, just because
the neighbor did. And so on. Works great.

I have yet to see where indulgence and luxury brought anyone true
happiness. Of course whenever I read Flying Magazine that mantra goes
out the window for a few hours ...

 

[Joerg]

ditto. the prices I quoted were ex. GST.


I got the Tek scope because it has 4 independantly isolated channels.
and cost less than 4 P5200 diff probes. when I tossed in the power calc
module it was still less than 4 diff probes

Ok, that's specialty stuff that you kind of have to buy at the
mainstream mfgs. My turf is more at the higher frequencies where a diff
probe consists of a piece of coax, a 0.37" #43 toroid and some wire.

 

[Joerg]

SIMILAR THINGS HAPPENED AFTER THE FIBER LINK - NO DAMAGE. oops, sorry
about shouting

Wait until ol' Leroy motors along with his steam shovel on a flatbed
trailer and forgot to heed the max vehicle height regs. Or a squirrel
heads up the pole and finds that fiber sheathing is rather tasty.

A couple that owns two businesses down the road from here was told that
the telco will no longer repair their broadband line after the squirrels
ate it for the umpteenth time. Instead Fish&Game issued them hunting
permits to deal with the problem. This is not a joke, they showed them
to me.

 

[Joel Koltner]

Yes! And when it comes to beer, only the good stuff.

Hmm... so are you saving most of it, eh?

I have yet to see where indulgence and luxury brought anyone true happiness.
Of course whenever I read Flying Magazine that mantra goes out the window
for a few hours ...

True enough, although I think one can supplement their happiness with material
goods. Worked for Jimmy Buffet -- if you read his books, it's clear that
he's getting every penny's worth out of his flying boat (a Grumman Albatross,
that is).

---Joel

 

[Terry Given]

Ok, that's specialty stuff that you kind of have to buy at the
mainstream mfgs. My turf is more at the higher frequencies where a diff
probe consists of a piece of coax, a 0.37" #43 toroid and some wire.

I'll pinch that trick, ta! I invariably use a poicece of coax & a 50R
terminator to monitor current sense resistor waveforms, and often use
the 1k series R (a-la howard j.) for logic stuff, but hadnt thought of that.

Cheers
Terry

 

[Terry Given]

Wait until ol' Leroy motors along with his steam shovel on a flatbed
trailer and forgot to heed the max vehicle height regs.

hopefully the 400V will teach him a lesson


Or a squirrel

heads up the pole and finds that fiber sheathing is rather tasty.

MAF would be more upset than we would - no squirrels in NZ. my MA
workmates used to think I was bonkers, feeding squirrels - "dude,
they're just rats with good PR" one guy kept saying. I have a number of
photos of squirrels.....

A couple that owns two businesses down the road from here was told that
the telco will no longer repair their broadband line after the squirrels
ate it for the umpteenth time. Instead Fish&Game issued them hunting
permits to deal with the problem. This is not a joke, they showed them
to me.

LOL!

Cheers
Terry

 

[Joerg]

I'll pinch that trick, ta! I invariably use a poicece of coax & a 50R
terminator to monitor current sense resistor waveforms, and often use
the 1k series R (a-la howard j.) for logic stuff, but hadnt thought of
that.

It's really handy when you have to check out the turn-on and turn-off
behavior of a big FET or if you want to see how gracefully (or not...)
an inductor saturates. For the wire I often just use strands of CAT-5.
Had to buy two 1000ft spools to do the office LAN but used less than
half of each. So I'll be set until I put my teeth in a jar ;-)

 

[Terry Given]

It's really handy when you have to check out the turn-on and turn-off
behavior of a big FET or if you want to see how gracefully (or not...)
an inductor saturates. For the wire I often just use strands of CAT-5.
Had to buy two 1000ft spools to do the office LAN but used less than
half of each. So I'll be set until I put my teeth in a jar ;-)

I can see that. I just do splat tests on inductors - used to be with
current sensing ressitors or DCCTs for the bigger ones, but I now have a
complete set of AM503 x 4 A6302 x 3, A6303 x 1 (yay).

Cheers
Terry

 

[Robert Latest]

Frugality was taught by my parents and grand-parents. If it can be
fixed, don't throw it away. Keep things simple. Buy only the good stuff
because it'll last.

A friend's father always says: I'm too poor to buy cheap.