how to bypass dremel tool internal variable speed control?

[John Fields]

130PSI @ 10CFM is not "low pressure". I see all sorts of "standard
procedures" go on by monkeys with screwdrivers.


Routinely? Mine never have been. I know the Tek stuff mentioned
earlier is designed not to trap solvents and the gunk they leave
behind.


I'll agree there. If it's going to get that dirty in a couple of
years, perhaps one ought to clean house a little more often. OTOH,
I learned not to put towers directly on the floor. They make good
cat-hair vacuums.

 

[John]

Static electricity and electronics don't mix, not to mention breaking
things. Using a compressor to blow out computers may do more harm
than good.


Quite a different thing, though I wouldn't do this either, unless the
equipment was made for it.

One of the problems with blowing out electronics with high pressure air
is the ultrasonic vibrations that are set up by the air. The vibrations
can break the fine junctions on the chip itself.


John

 

[clare at snyder.on.ca]

I've handled CMOS devices with bare hands/no straps too, but the
plural of anecdote isn't data. The fact is that moving air will get
a charge. If the conditions are right you can zap something.

The other problem with the high pressure/volume of a shop compressor
is physical damage. Unless you're a pig, such things shouldn't be
necessary.

Never heard of a pressure regulator? 15psi air won't damage anything,
and except in desert conditions moisture is generally more of a
problem with shop air than static charge.

 

[clare at snyder.on.ca]

130PSI @ 10CFM is not "low pressure". I see all sorts of "standard
procedures" go on by monkeys with screwdrivers.

Neaver heard of a pressure regulator, I assume?

Routinely? Mine never have been. I know the Tek stuff mentioned
earlier is designed not to trap solvents and the gunk they leave
behind.

I said in disaster recovery situations. After a flood or fire, for
instance. Have you ever had a computer go through a fllood or a
fire???

Several customers of mine were in the disaster cleanup business. They
ROUTINLELY clead computers and electronics i this way.

I'll agree there. If it's going to get that dirty in a couple of
years, perhaps one ought to clean house a little more often. OTOH,
I learned not to put towers directly on the floor. They make good
cat-hair vacuums.

I alwys recommend at least 4 inches off the floor.
Again, you SELECTIVELY read. The "dishwasher" was used for cleanup
after fire and flood damage.

One of the WORST culprits for screwing up electronis today is
CIGARETTE SMOKE.

 

[msg]

John wrote:

One of the problems with blowing out electronics with high pressure air
is the ultrasonic vibrations that are set up by the air. The vibrations
can break the fine junctions on the chip itself.

Huh? A standard cleaning protocol involved immersion in an ultrasonic
freon bath, now replaced by other less-inert solvents; this involved
considerably more sonic power than that produced by an air nozzle.
Certainly one must exercise care when cleaning around delicate parts
such as fine-wire coils without encapsulation, paper parts, etc., but
by and large there is little risk in pressurized air cleaning (120 psi)
and IMHO the benefits far outweigh any small risks. I've been doing
it for far more years than I care to admit with excellent results on
industrial, military and consumer electronics. I have also had very
good results using high-pressure hot detergent and water for difficult
greasy accumulations; the cleaner is much like a dentist's tool or
a 'Water Pic' rather than the familiar domestic pressure washer.

The key in wet cleaning of electronics is a proper bake-out protocol
to insure that parts (such as transformers) with high-potential
connections are dry internally to prevent breakdown before applying
power.

Regards,

Michael

 

[Peter Dettmann]

I've handled CMOS devices with bare hands/no straps too, but the
plural of anecdote isn't data. The fact is that moving air will get
a charge. If the conditions are right you can zap something.

I guess most of us have handled CMOS in this fashion, and I did so
myself until made aware that failure rates of such treated equipment
was much higher than good procedure.

As a test, I directly applied standard 5kv 1/50 impulses to 800 PIV
diodes, and found that it was simple to get measurable change in
characteristic, but usually took several applications to produce an
actually unuseable diode.

So the warning is there, that you may not stop the device from
working, but it may not be the same as when the manufacturer provided
it to you, and certainly I would safely guarantee that any change will
not be for an improvement..

Peter Dettmann

 

[James Sweet]

130PSI @ 10CFM is not "low pressure". I see all sorts of "standard
procedures" go on by monkeys with screwdrivers.

130 PSI? I usually set mine to around 40 PSI for blowing dust off things.
Any decent compressor will have a variable pressure regulator.

 

[Michael A. Terrell]

Never heard of a pressure regulator? 15psi air won't damage anything,
and except in desert conditions moisture is generally more of a
problem with shop air than static charge.

I suppose you've never heard of a special nozzle made for
electronics. It has a radioactive isotope to prevent static problems.
Microdyne leased two of them for the production floor, because the
manufacturer didn't sell them.

Central Florida isn't a desert, but I suppose you've never seen a
commercial air compressor with a dryer?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

I'll agree there. If it's going to get that dirty in a couple of
years, perhaps one ought to clean house a little more often. OTOH,
I learned not to put towers directly on the floor. They make good
cat-hair vacuums.

If you install a bigger fan it will either remove all of the cat's
hair, or suck it into the computer. ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

130 PSI? I usually set mine to around 40 PSI for blowing dust off things.
Any decent compressor will have a variable pressure regulator.

I prefer to put a mini regulator and gauge by whatever tool I'm
using, to get a constant pressure.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[charles]

If you install a bigger fan it will either remove all of the cat's
hair, or suck it into the computer. ;-)

I don't think there's room for my cat inside my computer ;-)

 

[Michael A. Terrell]

I don't think there's room for my cat inside my computer ;-)

One of my tower cases HAD to sit on the desk, because it was taller
than the desk. It had 12 drive bays, and room for several cats.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[krw]

---
Indeed. I used to put my stuff on the floor in order to gain a
little extra desk space, but after seeing the air intakes turn black
and get clogged with whatever, they're now on my desktop and
breathing at about the same altitude as I am.

No matter how big my desk is (or how many) there is never enough
space on it[*]. I generally put the towers on a shelf beside the
desk. Even a foot off the ground is enough to keep them from
constantly vacuuming the floor.

[*] It seems seems to be a fundamental law of the universe that all
horizontal surfaces will be full of stuff.

 

[krw]

Neaver heard of a pressure regulator, I assume?

I guess they haven't. Static *is* still a problem.

I said in disaster recovery situations. After a flood or fire, for
instance. Have you ever had a computer go through a fllood or a
fire???

No, but if it ever were I'd simply salvage the data off the disk and
replace the hardware. I can't believe anyone would spend real money
to salvage *cheap* hardware, particularly an insurance company.

Several customers of mine were in the disaster cleanup business. They
ROUTINLELY clead computers and electronics i this way.

Not that I don't believe you, but...

I alwys recommend at least 4 inches off the floor.
Again, you SELECTIVELY read. The "dishwasher" was used for cleanup
after fire and flood damage.

One of the WORST culprits for screwing up electronis today is
CIGARETTE SMOKE.

Shouldn't be too bad today. Twenty years ago, when people smoked in
office buildings... Even so, hardware is cheap. Labor isn't.

 

[krw]

If you install a bigger fan it will either remove all of the cat's
hair, or suck it into the computer. ;-)

"It" being the cat, I assume you mean. ...makes too much noise. ;-)

 

[Smitty Two]

[*] It seems seems to be a fundamental law of the universe that all
horizontal surfaces will be full of stuff.

Thank god for gravity, or the vertical surfaces would be equally
cluttered.

 

[john]

John wrote:




Huh? A standard cleaning protocol involved immersion in an ultrasonic
freon bath, now replaced by other less-inert solvents; this involved
considerably more sonic power than that produced by an air nozzle.
Certainly one must exercise care when cleaning around delicate parts
such as fine-wire coils without encapsulation, paper parts, etc., but
by and large there is little risk in pressurized air cleaning (120 psi)
and IMHO the benefits far outweigh any small risks. I've been doing
it for far more years than I care to admit with excellent results on
industrial, military and consumer electronics. I have also had very
good results using high-pressure hot detergent and water for difficult
greasy accumulations; the cleaner is much like a dentist's tool or
a 'Water Pic' rather than the familiar domestic pressure washer.

The key in wet cleaning of electronics is a proper bake-out protocol
to insure that parts (such as transformers) with high-potential
connections are dry internally to prevent breakdown before applying
power.

Regards,

Michael

On older circuit boards when ic's were first introduced it was not
recommended to use high pressure air on the boards. One of the main
failure points on early chips was the bonding of the leads to the chip.
This has since been solved but I still remember having boards fail
after they were blown off with high pressure air.



John

 

[msg]

john wrote:

On older circuit boards when ic's were first introduced it was not
recommended to use high pressure air on the boards. One of the main
failure points on early chips was the bonding of the leads to the chip.
This has since been solved but I still remember having boards fail
after they were blown off with high pressure air.

Interesting. What package types were susceptible to this (or did it
matter)? Metal can TO-x ICs seemed to be the most reliable (RTL, HLL,
some DTL, etc.) but I found a lot of early ceramic packages suffered
from bad seals and permitted fungi to enter and grow inside (this
in equipment that had never been wet, just from operating
environmental conditions). These parts seemed also to lack proper
passivation internally.

Regards,

Michael

 

[john]

john wrote:




Interesting. What package types were susceptible to this (or did it
matter)? Metal can TO-x ICs seemed to be the most reliable (RTL, HLL,
some DTL, etc.) but I found a lot of early ceramic packages suffered
from bad seals and permitted fungi to enter and grow inside (this
in equipment that had never been wet, just from operating
environmental conditions). These parts seemed also to lack proper
passivation internally.

Regards,

Michael

The ceramic Ic's were supposed to be more reliable but in fact as you
said they had a higher failure rate. The sealant that they used was not
too good since in many instances the tops would come off the IC . I bet
the sealant was probably a little corrosive too.

The first generation of IC's had a very high failure rate in compared
to todays products. They were very heat sensitive and would act up
above 100 degrees F even though the rating was higher. If I found one
bad ic I would just change out every IC on the whole board that had the
same date code and install a second generation ic with the same number.
On some equipment you would automaticly change out a couple of parts
and it was fixed. One company insisted on using the cheapest parts
available but their advertising sold a lot of equipment in spite of the
poor reliablity of the product. Today ic's and transistors , other than
high power transistors, almost never fail unless something external
blows them out. The industry has come a long way since the fifties when
I first started in electronics.



John

 

[Gerald Miller]

Thank god for gravity, or the vertical surfaces would be equally
cluttered.

Check the front of the refrigerator.
Gerry }
London, Canada