how to bypass dremel tool internal variable speed control?

Neaver heard of a pressure regulator, I assume?

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 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.

Reply to
clare at snyder.on.ca
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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

Reply to
msg

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

Reply to
Peter Dettmann

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

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?

Reply to
Michael A. Terrell

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

Reply to
Michael A. Terrell

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

Reply to
Michael A. Terrell

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

Reply to
charles

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.

Reply to
Michael A. Terrell

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.
Reply to
krw

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

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.

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

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

Reply to
krw

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

Reply to
krw

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

Reply to
john

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

Reply to
msg

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

Reply to
john

Check the front of the refrigerator. Gerry :-)} London, Canada

Reply to
Gerald Miller

Then, thank God for magnetism, too. d8-)

-- Ed Huntress

Reply to
Ed Huntress

Air is also capable of introducing an ESD event. The tribo-electric effect.

Air is an insulator. Drag molecules of it across an isolated device (read blow), be it conductor or otherwise, and it WILL gain charge. Touch to ground, and there is a discharge.

Nearly every "air station" one will find in a proper electronics manufacturing facility will be at an ESD, properly grounded workstation so that such discharges only occur at a slow rate. The "air tool" operator is also supposed to remain grounded through a properly constructed ESD grounding system. Either heal straps on an ESD matting or floor set-up, or wrist or smock strap versions.

Reply to
ChairmanOfTheBored

Silver filled epoxy is the main chip bonding media. The air must be evacuated from it in proper use. The surface of it will "tarnish" after application.

We use "humiseal" on our applications.

Epoxies have come a long way since the sixties.

Don't know if I would have gone that far, but whatever.

The first IC chips were in the sixties. TI made them for Fairchild, and they went into missiles. Ten transistor elements.

Now, we have 200 Million plus transistor elements on a single die.

I think we are doing pretty good..

Reply to
ChairmanOfTheBored

Thank god for a lot of things...

Reply to
AnimalMagic

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