Digest for sci.electronics.repair@googlegroups.com - 25 updates in 5 topics

jurb6006@gmail.com: Feb 02 09:56PM -0800

Hey Lenster ! How did that thing ever turn out is it behaving (well) now or what ?
Jeff Liebermann <jeffl@cruzio.com>: Feb 02 11:11AM -0800

This might be of interest. A farmers group is leading a movement to
require manufacturers to supply service information, parts, etc. So,
far, legeslation has been introduced in 6 states. Kansas, Mass,
Minnesota, Nebraska, New York, and Wyoming so far. I don't know much
more than what I've read about it:
<https://repair.org>
<http://modernfarmer.com/2016/07/right-to-repair/>
<https://motherboard.vice.com/en_us/article/farmers-right-to-repair>
<http://ifixit.org/right>
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
ohger1s@gmail.com: Feb 02 11:47AM -0800

On Thursday, February 2, 2017 at 2:11:07 PM UTC-5, Jeff Liebermann wrote:
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
 
I think it will ultimately die out. It's a great idea, but manufacturers will say it's a safety issue or a proprietary issue.
 
In any case, it won't affect lower cost electronics. That will never happen.
dansabrservices@yahoo.com: Feb 02 12:49PM -0800

This idea has been proposed a number of times and is most often seen in relation to vehicles. At issue is the need to go to a dealer to get some things fixed. Independent service providers don't have access to the computer diagnosis or update software and thus can not fix everything. I have seen this from both sides (I have provided service as a dealer as well as independently). Manufacturers charge service companies money for access to proprietary information. This guarantees some level of work for that provider at least for that manufacturer's product. If all were allowed access, then there would be little to differentiate service providers. Also, who would provide warranty service? Given what little is paid for service under warranty, at least having access to the service information will hopefully create more non-warranty work.
 
Dan
whit3rd <whit3rd@gmail.com>: Feb 02 03:06PM -0800

> > This might be of interest. A farmers group is leading a movement to
> > require manufacturers to supply service information, parts, etc.
 
> I think it will ultimately die out. It's a great idea, but manufacturers will say it's a safety issue or a proprietary issue.
 
So? Let 'em document a safety issue. Iindustrial safety is NOT a closed-book issue,
it's a matter of public interest.
Sponsor a reverse-engineering session on any proprietary technology (and
publish everything). Customers, unlike employees, are not barred from disclosure.
 
The real issue, unfortunately, is that 'require to supply parts' is only possible if the
company and its suppliers exist unchanged as long as the goods do. Workarounds
like last-time-buy are prohibitively expensive in some
states (where inventory is taxed annually).
 
No current production line can replicate a 30-year-old engine computer.
John Robertson <spam@flippers.com>: Feb 02 04:44PM -0800

On 2017/02/02 3:06 PM, whit3rd wrote:
> publish everything). Customers, unlike employees, are not barred from disclosure.
> ...
 
> No current production line can replicate a 30-year-old engine computer.
 
I would disagree with your last statement.
 
If there is sufficient demand then some bright person will MAKE a
replacement computer for the 30 year old machine. In my industry
(pinball and other coin-op games) there are multiple suppliers of
circuit boards and computers for pinball games as far back as the early
70s. I am working on a replacement PCB for a 1975 motherboard that used
three 6530s (Rockwell) with a FPGA.
 
John :-#)#
--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
ohger1s@gmail.com: Feb 02 05:15PM -0800

On Thursday, February 2, 2017 at 7:45:07 PM UTC-5, John Robertson wrote:
> (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
> www.flippers.com
> "Old pinballers never die, they just flip out."
 
 
 
If anything, it might be easier to emulate an early car computer than anything, assuming the plan is functionality not originality. The bigger problem would be the relatively low tech coil and solenoid drivers.
John Robertson <spam@flippers.com>: Feb 02 05:20PM -0800

>> three 6530s (Rockwell) with a FPGA.
 
>> John :-#)#
 
> If anything, it might be easier to emulate an early car computer than anything, assuming the plan is functionality not originality. The bigger problem would be the relatively low tech coil and solenoid drivers.
 
Pinball games use lots of low-tech coils...and there are many
replacement driver boards out there.
 
John :-#)#
 
--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
pedro <me@privacy.net>: Feb 03 11:31AM +0800

On Thu, 2 Feb 2017 15:06:30 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:
 
>Sponsor a reverse-engineering session on any proprietary technology (and
>publish everything). Customers, unlike employees, are not barred from disclosure.
 
I have several pieces of equipment where the manufacturer's included
software licence statement *forbids* R/E and or disclosure of any
contents thereof.
 
The only way to test that in a jurisdiction is to have deeper pockets.
whit3rd <whit3rd@gmail.com>: Feb 02 07:51PM -0800

On Thursday, February 2, 2017 at 7:30:47 PM UTC-8, pedro wrote:
> software licence statement *forbids* R/E and or disclosure of any
> contents thereof.
 
> The only way to test that in a jurisdiction is to have deeper pockets.
 
The proposed legislation would supersede that 'requirement' by making it
illegal. At least, it'd be illegal within the jurisdiction of the law, but it'd be very
silly outside that jurisdiction, once publication has occurred.
Jon Elson <elson@pico-systems.com>: Feb 02 10:52PM -0600

John Robertson wrote:
 
 
> circuit boards and computers for pinball games as far back as the early
> 70s. I am working on a replacement PCB for a 1975 motherboard that used
> three 6530s (Rockwell) with a FPGA.
The problem is that anything to do with the emission control system has to
be certified to not alter the emissions of the car. Hmmm, maybe won't
matter a lot on a 30 year old car (if it even HAD a computer).
But, making after market replacement parts for any part of the emissions
system has to go through a lot more than somebody making a wiper motor or a
fender.
 
Jon
jurb6006@gmail.com: Feb 02 09:20PM -0800

You certainly know where to find those big cans of worms. This goes alot deeper. The fact is that you own nothing, you are just a holder in good conduct.
 
When you think you buy a car, you are simply buying a title to that car. The actual proof of ownership is called a Manufacturer's Statement Of Origin. The state in which you live takes that, records ad then destroys it and issues you a certificate of title or similar instrument which is nothing but a license. The last state that would issue license plates on an MSO IIRC was Tennessee and I am pretty sure they stopped.
 
The same thing applies to real estate. The Constitution says property cannot be taken without compensation, but they can take it for taxes as easily as your Mother could take a toy away from you when you are five years old. Why ? Because they already owned it. You pay for it, they own it just like your car. In fact, the network of laws written from the Trading With The Enemy Act all the way to the US bankruptcy papers decades ago make it clear that you are actually property and property cannot own property. Also realize that your 1040 form every year is an actual contract with a mandatory oath. Nothing else, a contract. That's why 80 % of the people who beat the IRS do not file. But that is a different subject.
 
We are on the losing ed of this, and as far as I am concerned the older the better. My next car will have no ECM at all in it. Ever see the hydraulic schematic for a THM400 transmission ? That thing is a hydraulic analog computer. But you can put a shift kit in it. Actually I frown o any modifications to a THM400 because it is the last thing they designed right.
 
I do not need the internet on my phone. I do not need a user configurable dashboard on my car or tractor or any other damn thing. They shove this shit down your throat because that is what they have. You buy it or do without.
 
Don't even get me started on any software EULAs. They all say the same thing. We own everything, you o wn nothing. If our software destroys your hardware you are out of luck. If you decompile or otherwise modify our software we can sue you and take everything we own from you. That means everything folks.
 
How to fight back ? Well eventually we have to get the young into it, but don't buy anything. The only thing they understand is money. When they see you fitting a custom molded housing or something on a 1964 Oliver farm tractor rather than buying the new John Deere with their easy credit terms, they might take note. And 3D printing will help in some things.
 
And yes, you CAN replicate a 1980s ECM for a car. The O2 sensor controls the timing and mixture, the vacuum or MAF sensor controls the mixture and timing, with those priorities. As long as you can get a pulse from the cam, sometimes even just the crank, you can make any engine run. Twelve volts to the injectors, ground the other side to fire. Predetermined values for startup until it hits 400 RPM.
 
John P was quite the character. Tells me, about a car that keeps killing the battery and we were talking 1970s cars here, he says "Get you a wire cutters and get under the dash and cut every damn wire down there except for the headlights". Sounds pretty flippant but that might be our last resort.
 
Now TVs, people are just going to have to do without them. Idiots threw out all their old CRT TVs and now are caught in a trap. And we tried. This was our life in business, and now we're dead.
 
We considered many options, both well monied and not. We found out that it is a losing game. We could go out and buy TVs new, exact same model number, serial numbers the same up to the last five characters and NOT ONE SINGLE PART FITS. Not even the god damn speakers !
 
Shopjimmy made great strides, but we were the guinea pigs. I proved one of their parts was bad and that it had exactly the same problem as the one that came out. It was a Tcon and it was clipping the video. The main had already been tried so it was the Tcon or the screen itself, and there is no way a screen fault would cause that symptom uniformly on the screen. So we had problems even testing the parts, even to board level. Luckily I found you actually could put a scope on the LVDS and got familiar with the waveforms in a plasma TV. Bought me a couple more years in the business but in the end I was selling buggy whips.
 
If we could get the government to do it, and believe me Trump is the most likely to do it, would be to require a warranty on all goods, commensurate with cost. you got a $500 smartphone you want to sell here ? Four year warranty and eight parts and supplies for the ASCs. Twenty grand car or tractor ? Twenty years. Thousand dollar plasma, six year warranty, and twelve for the ASCs.
 
And, the sum total of all the parts needed to build the unit cannot exceed double the MSRP.
 
Bottom line, many liberals see Trump as too brash and too whatever, but in some ways he might get something done. This country has been open season on malicious companies across the world for too too long. Really, IMO that tariff for the Mexicans should not be 20 %, it should be more like 75 %.
 
Offshoring of work in the US is taking advantage of echange rates and costs of living in other countries. In China, think they are living in grass huts ? Nope. They are driving their air conditioned cars to work on roads better than ours and getting better heath care than we are. They EXECUTED the head of their FDA for what the head of the US FDA does every day. Prescription drugs kill more people than illegal drugs in this country, in China, SEVEN PEOPLE died and they executed the guy.
 
And if you live near fracking and have kidney problems, your doctor is under a gag order not to discuss with you how those fracking chemicals destroy your kidneys and therefore renal function. (Pennsylvania, Dr. Rodriguez) you didn't think they just pumped water down there now did you ? But the formula is secret. Know why ? /because if it wasn't secret there would be a shit ton of lawsuits against the oil companies.
 
And they built that piece of shit in the golf that makes sure our shrimp is nicely greased up. They build pipelines that leak all the time and give that Native tribe up there ammunition to garner public support to shut down those pipelines that we desperately need. What are they making these pipelines out of, paper mache' ? Trump should say "Have your pipelines, but one drop of oil leaked is a million dollar fine and every gallon is a million dollar fine. that should pretty much please everyone because their bottom line cannot absorb that and it would put them out of business.
 
But the bottom liner is that the government is all for business ad doesn't give a shit about us whatsoever, until election day. now we got a half nuts loose cannon in there who might get something done.
 
I say we make every effort to use this time wisely.
jurb6006@gmail.com: Feb 02 09:23PM -0800

>"I think it will ultimately die out. It's a great idea, but manufacturers will say it's a safety issue or a proprietary issue."
 
Then we adopt the Jewish idea of a boycott. Let's see them bribe the government with no money. HAHAHAHAHA.
jurb6006@gmail.com: Feb 02 09:50PM -0800

>"
I have several pieces of equipment where the manufacturer's included
software licence statement *forbids* R/E and or disclosure of any
contents thereof. "
 
Some slick lawyer might find a way to break that. Like a no competition clause in an employment agreement. There has to be a geographical or other area specified and a time limit or the courts will usually not enforce it.
 
Say I have a 15 year old Tek scope that ruins XP. I will hire school kids in China to decompile and fix the software as I see fit. When they stopped support they terminated whatever contracts they may have had with me, and I double dog dare them to sue me. Let's air ALL the dirty laundry, and I will make it a point to have live TV coverage of the whole trial as well as summaries on the evening news every night, because we are not alone. Look at al the people who have tried to eek out a living helping the repair industry. From Howard W. Sams reverse engineering to Asti making aftermarket transformers etc.
 
You know, they might put that revolution sensor in an engine where you really can't get to it, but you can drill a hole in the frikken valve cover and pick up a pulse off of one of the valves. that gives you phase as well as which side is firing, which doesn't always matter because half of the older designs fired two injectors and plugs at once and did not need a cam pulse at all. Hell some of the late 1980s cars we might be able to make better than new. Problem is the bodies rust out so we need good welders. Let's ho9pe the digitalennials don't start fucking with them or we'll have welders just using straight house current with a ballast like we used to in the old days.
 
Wanna see some real USian ingenuity ? Throw me a couple of million. I mean it. Know what you'll see ? Computers that can run any engine, and later transmission. (my buddy the engineer always buys stick shift cars, I actually wondered if he could even drive an automatic for a while but then eventually I saw him do it...)
 
You'll see these car bodies from the 1990s fixed, new ECMs and they pass emissions (pre OBD2). And last but not least, IF you select by switch, the lights go on immediately when you ope the doors and they go off imediately when you close the doors. The lights do not go on or off without your command. And sorry, if you want the driver window all the way down you have to hold the button. And in any case those plastic tapes they use on the window regulators will be replaced by steel ones.
 
With all that, your great Grandson can drive your Buick Roadmaster until he is 140 years old. I always wanted one of those but they were too expensive and now they are too old. They had the old style headlight switch, the kind you pull out ! There were words in English, like "WIPER", "LIGHTS" and so forth instead of these icons. In the old windows I usually used File Manager. I do not need little pictures I know how to read. Take your icons and stick them where they are sure not to get a sunburn.
oldschool@tubes.com: Feb 02 02:53PM -0600

Why should someone replace ALL the capacitors on old Tube equipment?
 
It seems that some people advocate that.
 
I understand that the electrolytic caps contain chemicals which decay
over time, from the chemicals corroding the metal parts. So,
electrolytic caps should always be replaced. But why replace the old
paper caps coated with wax? All they are, is metal foil and paper rolled
up, and as long as the wax is sealing them to keep out moisture, why
should they become defective?
 
And for that matter, what are the new ones made from? Aside from being
sealed inside of some sort of plastic (instead of wax), are they not the
exact same thing inside?
 
While this is not part of my original intent for this message, I want to
ask if anyone remembers the old oil filled electrolytic caps in the
1930's and 40's radios? I never understood what the oil did inside of
them. But what I do remember is having one of them "blow". *SCARY SHIT*.
I plugged in some ancient chassis with those old oil filled caps, and
all of a sudden there was hot oil spraying all over me, from the tiny
hole in the top of it. After that, I always put a tin can over those
caps before plugging the device in. (or just replaced them). Those
seemed to almost always be bad. (Probably why they were not used to too
many years).
ohger1s@gmail.com: Feb 02 01:33PM -0800

> caps before plugging the device in. (or just replaced them). Those
> seemed to almost always be bad. (Probably why they were not used to too
> many years).
 
If you remove every paper and foil capacitor from an old tube anything and check them on a quality checker, you'll find most if not all showing some sort of defect. They may read OK value wise, but run a few hundred volts through them and you'll find most have a lot of internal leakage. The fact is that moisture does eventually penetrate the capacitors and causes problems.
 
I've heard that old Radiolas use large banks of paper and foil capacitors instead of electrolytics and most do just fine with their original caps. Supposedly it's because of the particularly fine rice paper imported from Japan used to construct these capacitors during the 1920s. These rice paper caps might escape degradation over the decades. Perhaps those who've restored a bunch of these can comment if they actually did dynamic testing of the capacitors.
Foxs Mercantile <jdangus@att.net>: Feb 02 03:38PM -0600

> Why should someone replace ALL the capacitors on old Tube equipment?
 
> It seems that some people advocate that.
 
Most "old" radios are from 1930-1960.
That makes them 87-57 years old.
 
Manufacturing has changed a lot.
 
I change all the caps simply because I don't waste my time
"troubleshooting" bad caps.
Bad caps can cause collateral damage.
Why risk it for the cost (low) of replacement parts?
 
Old electrolytic filter caps dry out.
It's a fools game to waste time trying to reform them.
Paper dielectric capacitor absorb moisture and that
combines with the acids in the paper and cause them to fail.
 
For the most part, mica, silver dipped mica and ceramic
capacitors are very reliable. The band ones, you can find
AFTER you've replaced the usual suspects and can actually
trouble shoot the radio rather than running around in circles
chasing known bad parts.
 
Yes, I've had to replace the occasional vacuum tube, or found
an open coil, but for the most part 99% of the radios I've
worked on, worked to a fashion by just replacing known bad
parts. I.e. Paper and electrolytic capacitors.
 
 
 
--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com
oldschool@tubes.com: Feb 02 04:44PM -0600

On Thu, 2 Feb 2017 15:38:45 -0600, Foxs Mercantile <jdangus@att.net>
wrote:
 
>an open coil, but for the most part 99% of the radios I've
>worked on, worked to a fashion by just replacing known bad
>parts. I.e. Paper and electrolytic capacitors.
 
I'm 66 years old. According to my doctor, I dont have any bad
capacitors, (just arthritis). :)
 
Seriously, I wonder what the life expectancy is for the new caps
(meaning the replacements for the wax coated paper caps. ???)
 
And what are these newer ones made from?
 
I know the mica and ceramic caps are reliable and last almost forever.
 
A for electrolytic caps, it seems that the newer ones have a much
shorter life than the old ones did. You'd think that it would be the
other way around with modern technology, but today the name of the game
to to make stuff as cheaply as possible, for profit, not long life.
After all, today's electronics, cars, even homes are disposible. That's
why those old radios still work after 60 or 80 years, while most stuff
made today is in a landfill in less than 10 years.
 
One other thing that most people dont know, is that if we have a nuclear
blast, all of the semiconductors will cease to work. That means all
modern electronics, radios, tvs, cpmputers, cars, and darn near
everything around us, will stop working. The only stuff that will still
work are tube based electronics and vehicles made which still have
ignition points in their distributors.
 
Most likely WE wont survive either, but if we do, all we will have is
the old stuff from the 1960s and earlier, to rely on. The internet will
be gone, since it's all run with silicon. Most radio transmissions will
also be gone, except those still powered with tubes. This day is coming
soon, and we will be tossed back into the early 1900s. Thats why we need
to keep this old technology alive. The gear we relied on during WW2 is
the gear we will rely on once again during the upcoming WW3.
Jim Mueller <wrongname@nospam.com>: Feb 03 02:13AM

On Thu, 02 Feb 2017 14:53:42 -0600, oldschool wrote:
 
> caps before plugging the device in. (or just replaced them). Those
> seemed to almost always be bad. (Probably why they were not used to too
> many years).
 
Actually, the electrolytic capacitors are more likely to be good than the
paper capacitors. Almost all of the paper capacitors I have from the
"old days" are bad, even if they were never used while a small number of
the electrolytics are still functional.
 
The paper capacitors were made of sheets of foil separated by paper,
"sealed" in wax. Unfortunately, wax isn't a very good seal; moisture can
penetrate it. These capacitors were a know failure point 10 years after
a set was made. There just wasn't anything better to replace them with
(at a reasonable price). Modern capacitors are made from plastic film
that is much less affected by moisture and is a better insulator in the
first place.
 
The old electrolytic capacitors you are talking about don't sound like
the oil filled variety. Indeed, if they are electrolytic, they aren't
oil filled. Oil filled capacitors aren't polarized and many of them are
good today. They were the high quality capacitors used in military and
premium industrial equipment; you seldom find them in consumer gear
unless someone has repaired it with surplus parts. The capacitors you
talk about are more likely wet electrolytics. They aren't filled with
oil but with an acid. They are indeed all bad; don't power a set that
has them. Sometimes they leak if you turn them upside down (the vent
hole you mentioned). And be careful not to puncture them while you are
removing them. If there is still any acid inside, it will corrode any
metal it gets on.
 
You can still get high quality electrolytic capacitors from authorized
distributors like Mouser or Digi-Key. No-name ones from Amazon or Ebay
are likely to be junk. Name brand ones from these latter sources may be
counterfeit.
 
While tube electronics may survive a nuclear war, it is irrelevant.
There won't be any electricity to run them. The power plants are
controlled by computers. Likewise, having your own generator won't help
either. Many of the new ones are also semiconductor based, and you won't
be able to get gas to run them since the pumps at the gas station are run
by electricity which won't be available. Solar cells are also
semiconductors and the inverters used with them also use semiconductors.
So, if there is a WW3, don't count on ANYTHING electrical working.
 
--
Jim Mueller wrongname@nospam.com
 
To get my real email address, replace wrongname with dadoheadman.
Then replace nospam with fastmail. Lastly, replace com with us.
Jeff Liebermann <jeffl@cruzio.com>: Feb 02 06:36PM -0800


>I'm 66 years old. According to my doctor, I dont have any bad
>capacitors, (just arthritis). :)
 
I'm 69 years old. My body mechanic says I have pump and inside
plumbing problems. Perhaps I should replace him with a plumber?
 
>Seriously, I wonder what the life expectancy is for the new caps
>(meaning the replacements for the wax coated paper caps. ???)
 
There are online lifetime calculators for electrolytic and other types
of capacitors. For example:
<http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx>
<http://www.chemi-con.com/education> (click on Capacitor Life)
The major culprit is internal heating from high ripple current
resulting the electrolyte leaking or evaporating. Temperature also
has a big effect. There are graphs on the capacitor data sheets that
approximate the lifetime characteristics.
 
>And what are these newer ones made from?
 
For electrolytics, try polymer caps:
<https://en.wikipedia.org/wiki/Polymer_capacitor#Lifetime.2C_service_life>
<http://www.mouser.com/pdfdocs/Panasonic_Capacitors_WP_final.PDF>
 
>I know the mica and ceramic caps are reliable and last almost forever.
 
Not all ceramics are that reliable. MLCC (multi-layer ceramic caps)
are rather fragile and microphonic.
 
>A for electrolytic caps, it seems that the newer ones have a much
>shorter life than the old ones did.
 
Nope. The old ones filtered at 120 Hz. The new caps filter at 100 to
300 KHz. Internal dissipation follows frequency.
 
>That's
>why those old radios still work after 60 or 80 years, while most stuff
>made today is in a landfill in less than 10 years.
 
Todays products are intentionally designed to be difficult to repair
and to only last as long as the warranty period. With the proper
design tools and models, it is possible to predict the life of an
electronic (or mechanical) product. Anything that lasts longer than
the warranty period is deemed to be "over-designed". It is then
redesigned using lower rating or cost components so that everything
blows up at the same time. I've seen it happen.
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
boomer#6877250@none.com: Feb 02 02:26PM -0600

I was looking at the commercial isolation transformers and they are very
costly, so I decided to build my own. After all, all they are is a
transformer with a power cord on the primary and an outlet (and fuse) on
the secondary. And I already have an enclosure to put it in.
 
I'm looking at a bare transformer to use as an 120v isolation
Transformer. (120v in, 120v out). The transformer primary is 480 / 240.
The secondary is 240 / 120.
 
This is for single phase 60 cycle AC. (U.S. power).
 
Will it work if I connect the 240 lugs on the primary to 120 volts, and
use the 240 lugs on the secondary to obtain 120 volts.
Electrically, this makes sense, but I am not 100% sure, so I thought I'd
ask.
 
Also, this Transformer is rated at 750 va.
 
Using the calculator chart on
http://www.rapidtables.com/calc/electric/va-to-amps-calculator.htm
750 va should give me 6.25 A output. (Which should be enough amperage
for anything I need to test on my bench).
 
However, since this transformer was intended to be used at 240 / 480 on
the primary, will it still give me 750 va (6.25 A) on the secondary if I
run it on 120v?
 
Thanks
dansabrservices@yahoo.com: Feb 02 12:52PM -0800

> the primary, will it still give me 750 va (6.25 A) on the secondary if I
> run it on 120v?
 
> Thanks
 
My read on this is that the transformer converts input to 1/2 voltage on output. This means that connecting 240 on the input side will result in 120 on the output side (similarly 480 ==> 240).
 
You need a 1:1 transformer not a 2:1 as described here.
 
Dan
 
Note: If the transformer you have has multiple windings or taps, it may be usable as a 1:1 transformer. How many connections are there?
boomer#6877250@none.com: Feb 02 03:21PM -0600

On Thu, 2 Feb 2017 12:52:28 -0800 (PST), dansabrservices@yahoo.com
wrote:
 
 
>Dan
 
>Note: If the transformer you have has multiple windings or taps, it may be usable as a 1:1
> transformer. How many connections are there?
 
In case I was not clear.
 
Primary is labeled 240 or 480 v
Secondary is labeled 240 or 120
 
What I want to do is connect 120 volts to the primary winding intended
for 240.
 
Then use the secondary winding intended to be for 240. This would be
1:1, except I'm running 120 volts into windings made for 240volts.
Ralph Mowery <rmowery28146@earthlink.net>: Feb 02 05:48PM -0500

In article <78879ct2du83u9c4rc0je30hghd7j0kmn0@4ax.com>, boomer#6877250
@none.com says...
> for 240.
 
> Then use the secondary winding intended to be for 240. This would be
> 1:1, except I'm running 120 volts into windings made for 240volts.
 
You will probably have to reduce the current drawn as the size of the
wire will be smaller than if it was for 120 volts.
"pfjw@aol.com" <pfjw@aol.com>: Feb 02 09:30AM -0800

Please Note The Interpolations.
 
 
> A few years back Geraldo Rivera did a TV special where a hidden vault, chock full of old electronic components, was opened.
 
Funny thing - there is nothing on Google, Geraldo's Website, nor any other reference putting that gentleman together with "electronic(s)", "capacitor(s)", "condenser(s)" nor any other of several variations. True, I only did two searches. Please provide a link as the originator of this evidence.
 
They found many thousands of (strangely and coincidentally) the most popular canned capacitors that would be most in demand years later. All of these were thoroughly cleaned, buffed, and relabeled. Oddly, of the thousands that were sold dried up and inert, no one figured out the cans themselves were defective and were in fact just old dead stock, except Phil.
 
I am beginning to smell a rat (troll, at least). "...nobody figure out... except Phil." Sarcasm at its finest, given the reputation of those peddling these so-called 'defective' caps. Between AES, VTA and any of several other international vendors, were there the slightest smell of problems with these caps, they would drop them like plutonium.

> You can do better..
 
No, so far, you have no more than anecdotal evidence. If you are trolling, that is all you need. If you are actually trying to make a point in support of Phil - or anyone else - a bit more than vague statements supported by anecdotes of dubious veracity is required.
 
a) Al Capone purportedly had a vault.
b) Geraldo purportedly opened it.
c) There are lots-O-NOS caps out there being sold under various conditions and descriptions. Mostly right out in plain sight. But, of a certainty, it is vaguely and perhaps *just* possible that there are unscrupulous sellers out there selling all sorts of twaddle to the gullible.
 
In this case, a) + b) ≠ c).
 
Peter Wieck
Melrose Park, PA
You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page.
To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

1 Response to Digest for sci.electronics.repair@googlegroups.com - 25 updates in 5 topics

February 11, 2017 at 9:22 PM

At Take Free Bitcoin you can claim free satoshis. Up to 22 satoshis every 5 minutes.

Post a Comment