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Algeria Horan <algeriahoran@algeria.horan.net>: Oct 31 04:08PM How long do LED shop/ceiling lights really last at full output anyway?   In another thread, the topic came up that LED lights may not last as long nor as bright as claimed on the package:   Lights of America exaggerated LED light bulb performance http://archive.jsonline.com/blogs/news/246355581.html http://green.blogs.nytimes.com/2010/09/08/federal-agency-sues-led-bulb-maker/   Since the failure mechanism is electronic as much as it's the fact that LEDs diminish in light output over time, I wondered how long the LED lights (the entire unit, including electronics) really last, and, what "rules" were in place for the claims on the package (since I never get the life that the fluorescent or incandescent bulbs claim either).   As just one (admittedly egregious) example, the bulbs referenced above:   CLAIM: Replaces light output from a 40 Watt bulb (aka 400 lumens) TESTS: The F.T.C. found the bulbs produced only 74 lumens of light   CLAIM: The LED bulbs in question would last 30,000 hours TESTS: They lost 80 percent of their light output after only 1,000 hours   That didn't even cover sudden failure from the electronics.   So, I wonder aloud ... How long do LED shop/ceiling lights really last at full output anyway?

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Jon Elson <elson@pico-systems.com>: Oct 30 02:27PM -0500 Bruce Esquibel wrote:   > Looking up a 1964 Buick Wildcat, 425cu 8cyl (at random), they have > closeout sets from $6.74 to high performance ones with ceramic boots, > $73.89.   WOW, this looks WAY better than any car parts I've bought in the last couple decades! Maybe they have a bunch of stock left over from 1950 that they are still selling a couple of per year. Ignition coils run $50, spark plugs are about $10 each, etc. Haven't had any rotors, points or distributor caps in some time.   I'd be real cautious driving anything made before 1960 or so, if you hit anything the steering shaft goes through your chest.   Jon

Bob Engelhardt <BobEngelhardt@comcast.net>: Oct 30 10:58PM -0400 On 10/30/2016 3:27 PM, Jon Elson wrote: ...   > I'd be real cautious driving anything made before 1960 or so, if you hit > anything the steering shaft goes through your chest.   That's the 1948 version of a safety feature - it keeps you from driving recklessly <G>.

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Ralph Mowery <rmowery28146@earthlink.net>: Oct 29 01:58PM -0400 In article <nv1ukv$mvn$1@remote5bge0.ripco.com>, bje@ripco.com says...   > Point is, it would be money more well spent just replacing all that compared > to doing whatever he wanted to do with the scope, which probably isn't going > to tell him anything.   I have not had a car with points in it in many years so may be way off on the following.   Wasn't the usual thing to change out the points, condenser, plugs and a few other things about every 10,000 miles or so back then ?   Seems to me that the 3 or 4 cars I owned with the old nonelectronics in them needed to be worked on all most all the time. I remember replacing a lot of plugs and some points, distributer caps and wires. None of those had over 100,000 miles on them. Now lots of cars go 100,000 without anything but oil changes and tires.

Bruce Esquibel <bje@ripco.com>: Oct 30 12:02PM > on the following.   > Wasn't the usual thing to change out the points, condenser, plugs and a > few other things about every 10,000 miles or so back then ?   Yes.   That's really the reason this bit about using some scope to monitor/examine the ignition system is borderline silly. It wouldn't matter if that car was some "barn find" where it's been under a bundle of hay for the past 50 years or a daily driver that someone was using for weekend tours of the countryside, those parts were part of the normal maintance schedule and should be totally replaced on a regular basis.   It would be surprising that the engine shouldn't be rebuilt every 25,000 miles as well. Most pre-WW2 cars from the 20's and 30's barely made the 10,000-12,000 mile range before needing a rebuild. Most of those didn't have oil filters, there used to be kits to use rolls of toilet paper as a replaceable cartridge.   The post war ones were better but no where near todays standards. Even into the early 60's, getting into the 50~60,000 mile range was "good". Getting up to 100,000 without a major overhaul was exceptional.   Something from 1948, if all original, would be a miracle if all it really needed was the ignition system replaced. It's cheap enough to do and see but wouldn't suprise me if the rings were gone, crank out of tolerance or even a lesser job of the cam lobes in the distributor were flat.   All the tech available today isn't going to change the need of getting your hands greasy.   -bruce bje@ripco.com

Jon Elson <elson@pico-systems.com>: Oct 29 03:20PM -0500 >> in their bedroom. It was there when we moved in. The regular switches >> around the house made really loud snaps.   >> Nowadays, switches are nearly all virtually silent.   The switches we have are almost all cam-operated, not snap-action. A bump on the handle presses a contact arm onto the other contact. These fail generally by fatigue of the arm, not by burning out of the contacts. They do seem to last 20++ years in residential use. Most of the ones I've replaced are most likely the original ones installed when the house was built, 40 years ago.   Jon

Jon Elson <elson@pico-systems.com>: Oct 29 03:16PM -0500 > Thanks for the motor update. I have been thinking about that motor and > why they would use it and it must be because shaded pole motors are so > inefficient. Right, it has to be fairly efficient as there is no fan. Since the rotor is in a sealed plastic housing, there is no external shaft to connect a fan to. That's probably why they cycle the pump on and off during drain/spin cycles.   I guess the permanent magnet rotor is way more efficient than an induction rotor, too. The only tricky part is assuring the motor starts every time you apply power.   Jon

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Jon Elson <jmelson@wustl.edu>: Oct 28 02:36PM -0500 N_Cook wrote:       > So like a smaller version of a central heating circulation pump, > magneticc oupling through a membrane. At least washing m/c get used > through the summer , so nver a chance to seize up   Well, I've seen magnetic-coupled pumps. These have a totally standard induction motor turning a magnet outside the housing, and a magnet turning the impeller inside.   This is different - there is only one magnet, and the stator poles outside. So, it is a 2-pole permanent magnet synchronous motor. The only trick is to make sure the thing starts every time power is applied.   Jon

"pfjw@aol.com" <pfjw@aol.com>: Oct 28 01:18PM -0700 On Friday, October 28, 2016 at 3:23:18 AM UTC-4, N_Cook wrote:   > So like a smaller version of a central heating circulation pump, > magneticc oupling through a membrane. At least washing m/c get used > through the summer , so nver a chance to seize up   I have used TACO and Grundfos sealed hydonic circulator pumps - our present system uses two TACO systems and one Bell & Gossett 1/4-horse as it is a summer-winter system that makes domestic hot water as well. The TACO pumps have one (1) moving part installed as a cartridge, and behave as does any other AC induction motor designed without brushes. There is no 'magnetic coupling' in the true sense of the word, as there is only that single moving part. I would agree on the 'synchronous' description as the impetus has to comes from somewhere.   The Bell and Gossett, on the other hand has the standard induction motor using a spring-coupling to a separate pump housing with a sealed bearing. Much larger, much heavier, and much more powerful. That is what moves the approximately 110 gallons (400 liters) of water through the 34 radiators on a 2-pipe system, that includes just under 450 feet (146 meters) of pipe in total. The house was built in 1890, and substantially expanded in 1928, when the hydronic system was first installed. It is a 2-pipe, 3-zone system designed for gravity supply and return, with a single circulator not added until the 1950s. We converted from oil to gas and added the indirect water heater, that conversion requiring the two additional circulators. But the first Grundfos pump I installed about 38 years ago is still going strong. And my first TACO pump (27 years) is equally good, so far. I have rebuilt our B&G twice - the first time just the coupling - the second time, the support bearings and coupling. I should have done the support bearings the first time. That, now, has 8 years on it, but is dated 1978 as the original install-date.   https://www.youtube.com/watch?v=E0X8m0BGZ1g   Peter Wieck Melrose Park, PA

ggherold@gmail.com: Oct 28 01:25PM -0700 On Thursday, October 27, 2016 at 1:15:26 PM UTC-4, Jon Elson wrote:   > Anyway, the pump bearings (water lubricated) are massively worn, and the > rotor eventually wore through the plastic housing.   > Jon   Have you looked for a replacement motor? I had some motor fail on a Kenmore washer and the local appliance dealer had the part.   George H.

Jon Elson <jmelson@wustl.edu>: Oct 28 04:23PM -0500 > Have you looked for a replacement motor? I had some motor fail on a > Kenmore washer and the local appliance dealer had the part. Yes, I ordered a replacement part through Amazon.   Ugh, yet another story. The replacement pump has a thermoplastic pump housing, while the original seemed like it was a thermoset. The pump leaked where the two parts were joined with a raidal O-ring seal. Removing the housing, it was visibly non-circular! So, I had to take the old housing and O-ring and put them on the new pump. It is now back in operation, but I'm not so happy about their crummy parts and the number of times I had to disassemble the thing to make it right.   Jon

N_Cook <diverse@tcp.co.uk>: Oct 29 11:04AM +0100 >> through the summer , so nver a chance to seize up   > I have used TACO and Grundfos sealed hydonic circulator pumps - our present system uses two TACO systems and one Bell & Gossett 1/4-horse as it is a summer-winter system that makes domestic hot water as well. The TACO pumps have one (1) moving part installed as a cartridge, and behave as does any other AC induction motor designed without brushes. There is no 'magnetic coupling' in the true sense of the word, as there is only that single moving part. I would agree on the 'synchronous' description as the impetus has to comes from somewhere.   > The Bell and Gossett, on the other hand has the standard induction motor using a spring-coupling to a separate pump housing with a sealed bearing. Much larger, much heavier, and much more powerful. That is what moves the approximately 110 gallons (400 liters) of water through the 34 radiators on a 2-pipe system, that includes just under 450 feet (146 meters) of pipe in total. The house was built in 1890, and substantially expanded in 1928, when the hydronic system was first installed. It is a 2-pipe, 3-zone system designed for gravity supply and return, with a single circulator not added until the 1950s. We converted from oil to gas and added the indirect water heater, that conversion requiring the two additional circulators. But the first Grundfos pump I installed about 38 years ago is still going strong. And my first TACO pump (27 years) is equally good, so far. I have rebuilt our B&G twice - the first time just the coupling - the second time, the support bearings and coupling. I should have done the support bearings the first time. That, now, has 8 years on it, but is dated 1978 as the original install-date.   > https://www.youtube.com/watch?v=E0X8m0BGZ1g   > Peter Wieck > Melrose Park, PA   A problem with synchronous motors, is they can start backwards unless there is a "kicker" mechanism

etpm@whidbey.com: Oct 29 09:11AM -0700 On Thu, 27 Oct 2016 12:15:18 -0500, Jon Elson <elson@pico-systems.com> wrote:     >Anyway, the pump bearings (water lubricated) are massively worn, and the >rotor eventually wore through the plastic housing.   >Jon Greetings Jon, Thanks for the motor update. I have been thinking about that motor and why they would use it and it must be because shaded pole motors are so inefficient. Eric

Jon Elson <jmelson@wustl.edu>: Oct 28 04:29PM -0500 Bruce Esquibel wrote:       > I can't see a set of new plugs, wires, cap, rotor, points and condenser > running more than $50 dollars or so. I'd just replace everything and if > you think something is wrong, look elsewhere.   Oh, wow, have you bought any car parts lately? A set of wires ONLY for a 4- cylinder car can run $50 at the NAPA parts store. Parts for a 1948 car are likely to be VERY hard to find specialty items. IF J. C. Whitney doesn't have them, you could be out of luck.   The guys at the local Auto Zone would not even know what the term "points and condenser" means.   Jon

"tom" <tmiller11147@verizon.net>: Oct 28 07:47PM -0400 "Ivan Vegvary" <ivanvegvary@gmail.com> wrote in message news:da0ebbe5-3ac9-4984-a366-4b350e9a7bb9@googlegroups.com... > Of course the only electronics in a 1948 auto is the ignition system. > Would love to look at 4 cylinders (8 total) at a time with the Rigol. > I do have inductive pickups that I can salvage from timing lights.   For working around car ignition systems, I would look for one of the older tube type Tektronix models. Try 535, 545 for the large ones or a 453 with the nuvistor tubes in the vertical front end.   These would survive better than a usual fet input amp.   Just my 2 cents.

Bruce Esquibel <bje@ripco.com>: Oct 29 10:45AM > have them, you could be out of luck.   > The guys at the local Auto Zone would not even know what the term "points > and condenser" means.   Yeah but if you expand your horizons a bit beyond NAPA and AutoZones, there are places like Rockauto.com, which is probably 1 stop shopping for it.   He never mentioned models and engine types but I just looked up a 1948 Pontiac Streamliner with a 3.9L (239 cid) L6...   condenser is $1.31 to $8.52 dist cap $8.72 rotor $3.12 to $4.78 points $9.64 to $12.29 ignition coil $10.11 to $14.56 spark plugs $1.10 to $1.90 each   I don't see wires listed for those in 1948 but, those are just wires. Looking up a 1964 Buick Wildcat, 425cu 8cyl (at random), they have closeout sets from $6.74 to high performance ones with ceramic boots, $73.89.   So maybe $50 was on the light side, so if I say under $100 make you feel better?   Point is, it would be money more well spent just replacing all that compared to doing whatever he wanted to do with the scope, which probably isn't going to tell him anything.   Like someone else pointed out, a dwell meter (forgot about those), timing light and volt-ohm-meter will be far more useful.   -bruce bje@ripco.com

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 29 05:32AM -0400 Jon Elson wrote:   > OHHH, this explains a LOT! Wish I knew that 30 years ago!   > Thanks,   > Jon     I bought a used re-inker about 25 years ago and the manual had that warning. It said that some type of clay was used in stamp pad ink. The ink they sold was cheaper, and denser. It had a hollow post with a tiny hole in the side. A clock motor turned the feed inside the cartridge, as a streak of ink was applied to the center of the ribbon. By the time it has made one full loop, the ink has spread across most of the width of the nylon fabric.   -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

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Tim Schwartz <tim@bristolnj.com>: Oct 27 01:14PM -0400 On 10/27/2016 10:18 AM, N_Cook wrote: > external emitter R,or is it just referring to doubling-up ? > datasheet > http://pdf1.alldatasheet.com/datasheet-pdf/view/38213/SANKEN/SAP15/+2732WUOYLI.OcU.utw+/datasheet.pdf   Hello Nigel,   What amp are these in? I know Arcam used them in several products, such as the A65/75 series. I night have a good PDF of the data sheet if you need it. The pinout is different on the SAP15-N (NPN) and the SAP15-P (PNP)   Regards, Tim Schwartz Bristol Electronics

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Oct 28 08:49AM +1100 On 28/10/2016 1:18 AM, N_Cook wrote: > external emitter R,or is it just referring to doubling-up ? > datasheet > http://pdf1.alldatasheet.com/datasheet-pdf/view/38213/SANKEN/SAP15/+2732WUOYLI.OcU.utw+/datasheet.pdf   **I did once in a client's amp, to see what would happen. It worked fine, but I decided to fit new devices to be certain. These Sanken things are horrible. Sanken has a nasty track record of releasing devices, then ceasing production after a few years. After which, substitutes can be either difficult or impossible to obtain. Give me a standard 3 terminal transistor every day. I'm presently working on a 1975 vintage Accuphase, which will accept modern replacement devices quite nicely. In 10 years, those Sanken things will be unavailable and the units that they're fitted to will be boat anchors. I advise anyone who will listen to avoid products that use Sanken devices for that reason.   -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Oct 27 11:57PM +0200 On 27.10.16 16:18, N_Cook wrote: > external emitter R,or is it just referring to doubling-up ? > datasheet > http://pdf1.alldatasheet.com/datasheet-pdf/view/38213/SANKEN/SAP15/+2732WUOYLI.OcU.utw+/datasheet.pdf   "alldatasheet.com currently unavailable" GRRRRRR

Phil Allison <pallison49@gmail.com>: Oct 27 06:47PM -0700 N_Cook wrote: > I intend removing both , of the failed channel , to check out of > circuit, but anyone jumpered in an external .2R in these circumstances > and no further problems from cracked die etc as this R is part of the die?   ** The 0.22 ohm is not part of the die, but a separate thick film resistor as stated in the Sanken data.     > The datasheet I think , in fractured English, says the thermal safe > operating over-current zone, for the built in .22R is deliberately > lower than the Darlington itself.   ** The max current rating of the 0.22ohm is somewhat less than the Darlington itself - but this is not deliberate, just a practical limitation. If the internal resistor has failed, the Darlington may still be OK.   Designers can use an external WW resistor if needed, or add a current limiter circuit that protects the inbuilt one.   I have seen a lot of these devices used in powered speakers made by dB Technologies - their "Opera" series and others.   The "English" in the app notes is bloody dreadful.       .... Phil

N_Cook <diverse@tcp.co.uk>: Oct 28 08:19AM +0100 On 27/10/2016 22:49, Trevor Wilson wrote: > quite nicely. In 10 years, those Sanken things will be unavailable and > the units that they're fitted to will be boat anchors. I advise anyone > who will listen to avoid products that use Sanken devices for that reason.   After removing , it became obvious low ohmic C-E, so bang goes that idea. Perhaps 120V,12A standard pDarlington, with external .2R and 5 SMD Shottky diodes RTV'd on the top, rather than expensive old-stock SAP15. Cambridge A5 amp, made in DRC = The Congo ?

legg <legg@nospam.magma.ca>: Oct 28 09:16AM -0400 On Thu, 27 Oct 2016 23:57:02 +0200, Sjouke Burry >> datasheet >> http://pdf1.alldatasheet.com/datasheet-pdf/view/38213/SANKEN/SAP15/+2732WUOYLI.OcU.utw+/datasheet.pdf   >"alldatasheet.com currently unavailable" GRRRRRR http://pdf1.alldatasheet.com/datasheet-pdf/view/38213/SANKEN/SAP15.html

Chuck <chuck@mydeja.net>: Oct 28 08:26AM -0500 On Fri, 28 Oct 2016 08:49:41 +1100, Trevor Wilson >quite nicely. In 10 years, those Sanken things will be unavailable and >the units that they're fitted to will be boat anchors. I advise anyone >who will listen to avoid products that use Sanken devices for that reason.     Does anyone remember the Sanken output IC that JVC used in its integrated amplifiers that had the exact same number as used by other manufactuers but when replaced by any IC not sold by JVC there was huge notch distortion? I spent quite some time on the first one that I repaired. After the ICs were no longer available from JVC, I found by adding external resistors that the distortion could be eliminated.   I had an Accuphase E-202 amp and still have the service manual somewhere if this happens to be the amp you are working on and you need a schematic.   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Phil Allison <pallison49@gmail.com>: Oct 28 06:37AM -0700 Nutcase Kook wrote: > idea. Perhaps 120V,12A standard pDarlington, with external .2R and 5 SMD > Shottky diodes RTV'd on the top, rather than expensive old-stock SAP15. > Cambridge A5 amp, made in DRC = The Congo ?   ** ROTFL !!   https://www.avforums.com/threads/cambridge-audio-a5-any-owners-views.867584/     " Made under license in PRC "   PRC = People's Republic of China, established in 1949 by Mao Zedung.   No jungle monkeys involved ....       .... Phil

Jon Elson <elson@pico-systems.com>: Oct 27 12:15PM -0500 There was a discussion a LONG time ago about a washing machine pump motor. I have a Kenmore Oasis washing machine that I've had to do some repairs on. The drain pump has gotten clogged a few times (coins, nylons) and I've been able to remove the clog and get it going again. I posted a partial description of the motor, because I couldn't quite understand it. Now that the pump has finally gone to complete failure, I was able to investigate further.   So, it has a stator quite similar to a "phonograph motor" although there are no shaded poles, as I had expected. The rotor is a 2-pole ceramic magnet. The rotor runs in water, so there are really no seals required in the pump.   When digging in deeper, I found there is a slip coupling between the motor rotor and the pump impeller, that allows the rotor to make almost one complete rotation before it grabs the impeller. I suspect this is to allow the rotor to vibrate wildly until it gets into sync with the mains frequency. AHH, and the pump is clearly designed to run in either direction! Now, it is all starting to make sense. The pump does make a rattling noise before it starts. Kind of ingenious design, probably had to make a BUNCH of prototypes before they got it to reliably start spinning.   Anyway, the pump bearings (water lubricated) are massively worn, and the rotor eventually wore through the plastic housing.   Jon

N_Cook <diverse@tcp.co.uk>: Oct 28 08:23AM +0100 On 27/10/2016 18:15, Jon Elson wrote:   > Anyway, the pump bearings (water lubricated) are massively worn, and the > rotor eventually wore through the plastic housing.   > Jon   So like a smaller version of a central heating circulation pump, magneticc oupling through a membrane. At least washing m/c get used through the summer , so nver a chance to seize up

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 27 07:48PM -0400 Ralph Mowery wrote: > someone that has some old stock I doubt you will find it. > NCR K-575F ink. That is for the black. They made some purple or some > such color that had a similar number.     Do not use stamp pad ink. It contains a fine abrasive that works to keep the rubber face in good condition. it will eat the pin guides in an impact printhead.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

Jon Elson <elson@pico-systems.com>: Oct 28 12:18AM -0500 Michael A. Terrell wrote:       > Do not use stamp pad ink. It contains a fine abrasive that works to > keep the rubber face in good condition. it will eat the pin guides in an > impact printhead.   OHHH, this explains a LOT! Wish I knew that 30 years ago!   Thanks,   Jon

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 27 07:36PM -0400 rickman wrote: > the amount of taxes. Once when I called to ask about the quarterly > billed "franchise fee" and who it was going to, I was told they didn't > know and I would have to ask my franchise contact.   The 'franchise fee' goes to the local government, for their use of the right ow way.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 27 07:23PM -0400 >> motor controller would incorporate current limiting, and the current >> limit should be set below the fuse blowing current.   > Bluntly, I would be surprised if the motor controller is anything more than a primitive SCR speed control and a fuse as a last-resort. These go-buggies are just short of a racket, with a very few genuine exceptions. And a brush-type DC motor will pull current even when not turning right down to a dead-short when the voltage drops below what is necessary to turn the motor against the load - and THAT is what blows the fuse.       I would be surprised to see an SCR that worked in a DC circuit, unless it was a GTO type. All of the controllers that I've had on the bench were PWM, with sets of PowerFETs for each motor. Each motor was driven by a high power H bridge. All of the controllers that I've had on the bench were built with International Rectifier components.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

jurb6006@gmail.com: Oct 27 10:48AM -0700 On Thursday, October 27, 2016 at 8:08:11 AM UTC-5, Ivan Vegvary wrote: > Thank you all. Scope will not be used on ignition. Car runs fine. Lesson(s) learned. Great group! > Ivan Vegvary   This is one of those times when an old CRO would come in handy. A 20 MHz job from the 1970s would be fine.   You would connect the vertical input to where the wires goes from the points/condenser to the coil. The other channel you use to trigger by loose coupling to cylinder #1.   Set the time base so you see eight pulses if it has a eight cylinder. They should all be the same amplitude. If some are higher the gap of the plug might be wider or the wire starting to fail. If some are lower that would indicate a spark leak, like loss of insulation or a fouled/semi fouled plug.   Once you eliminate all ignition faults having the plug gaps all the same and the wires all good, then if there are variations in the pulses that indicates the relative compression of that cylinder. A cylinder with low compression will yield a lower amplitude pulse if all other things are equal.   I don't remember what kind of voltage you get to the coil on one of those but I think it was around 300 volts. Many newer scopes only go up to 5V/div which with a 10X probe (always use a 10X probe to protect the front end, unless you REALLY need all that gain) gets you to 50V/div. You can go into "UNCAL" mode if it goes off the screen but you are at the upper limit of the front end of the scope now.   You can experiment with it by slowly pulling off one of the wires from the distributor. Don't pull it from the plug itself - I learned that the hard way. ZZZAPP !   You should see the pulse for that cylinder increase in amplitude. Take a wire and short the output of the distributor for that cylinder to ground and the amplitude will decrease. Don't let the thing run alot with o plug wire or anything on the distributor because those coils are current operated. When there is no arc the voltage tries to climb until there is a load and it might break down the insulative properties of the distributor cap or rotor. (this is even more important on newer cars)   Actually the easiest way to find a spark leak is a AM radio. Tue to the lower end of the dial and listen to the ZZZZZZZ sound which will increase in pitch as you rev the engine. But if you get a POP POP POP sound that means you probably need wires or a distributor cap. The does not tell you which cylinder but it doesn't matter, the wires should be changed as a set and the distributor cap is common to all so that is that.   The one time I ever used a scope on a car was a 1990 Olds with a VIN C 3800. It stalled sometimes when hot and would not restart. The way it acted smelled like a semiconductor fault and sure enough the crank sensor was failing. We read up on how the system works and I stuck the scope probe where it needed to be. A garage would have taken a month to fix this but we were flipping cars at the time. I used to have a couple thousand worth of books on it but later sold them because I don't do that kind of work anymore for a couple of reasons.   Anyway, does that old Pontiac have a radio in it ? Now that can be a blast. You're looking at tubes ad a vibrator based B+ supply. I assume it is 6 volts, right ?   What can blow some people's mind is that those cars and even the radio will work if you put the battery in backward. It has been known to happen actually, that is why they used to polarize the generator. But they didn't really have to, nothing cared much about polarity. Even the radio, because the vibrator changed it to AC for a transformer the rectifier(s) after that took care of polarity, the filaments of the tubes don't care.   I think it did make a little bit of difference in the spark, but minor. The problem comes when you need or give a jumpstart. Sometimes you get that big spark and then you know that one or the other car is mis-polarized.   Later came the hybrid radios with the solid state output, then polarity became important, also then the alternator came out and it was not an issue anymore. It simply wouldn't run on reverse polarity because the diodes would short out the battery. In cars with a generator the charging current went through the ignition switch, or else the coils would discharge the batter forthwith. Therefore it was not a good idea to leave it on, to play the radio for example. then they came out with the "ACC" position on the ignition switch. It also wouldn't heat up the points if they happened to be closed.   While I greatly prefer 1960s and 1970s cars it is still a good thing to keep that old beast running.   I drove a 1950 Chevy once, it was almost like work. People don't know how good they got it now. They have no idea what it means to double clutch, and they have no idea how undeveloped the steering and suspension was back then. Driving those old cars is almost like driving a semi truck, but the new ones aren't even that hard.   Well OK, it isn't really all that difficult but I bet you don't take that thing to work every day...

jurb6006@gmail.com: Oct 27 11:14AM -0700 >"It's a novel idea but the scope isn't going to give you any >more ideas than >a good set of ears and eyes will. "   One thing a hillbilly taught me was if you have a miss and want to know which cylinder it is to put your hand on or near the exhaust manifold (depending on how long it ran) and one part of it will be cooler than the rest.   Another backyard mechanic taught me about timing chains. Take off a valve cover ad see how far backwards you have to turn the crank (with a wrench) to get the valves to move, more than a certain amount the needs timing irons.   The olman taught me that when an engine jumps time the cam is almost always late in phase which will give you higher measured compression but low vacuum. However that has changed because almost all cars use a tensioner. Some of them jump at shutdown and could be advanced instead. Sometimes it is the tensioner that goes bad.   The buddy who taught me about the timing chain trick actually brought a car to me after it had been to Mr Goodwrench and they said "Replace the engine". It was down to cam timing or the crank sensor which was terribly hard to replace in that model. It was running like shit and pretty much couldn't get out of its own way.   I looked at it and drove it and did not know much, just that it ran like shit. Eventually I removed the cover from the throttle body to see if it was getting a good stream of fuel. Well it was but when I tried to rev it up it spouted gas right out. I said "Tear down for timing chain". He said Mr Goodwrench said there is no timing chain, this old 151-4 has gears. The next day he shows up at my house with a broken timing chain tensioner.   Think Mr Goodwrench would give him back the fifty bucks they charged to misdiagnose the thing ? Hell no.   In my business you had hell to pay for a misdiagnosis. apparently the ASE certification males you like a doctor, you get paid even if the patient dies. Buncha shit IMO.

Ralph Mowery <rmowery28146@earthlink.net>: Oct 27 02:28PM -0400 In article <98054939-face-498f-8e94-20dcb3f3e9c3@googlegroups.com>, jurb6006@gmail.com says...   While I greatly prefer 1960s and 1970s cars it is still a good thing to keep that old beast running.   > I drove a 1950 Chevy once, it was almost like work. People don't know how good they got it now. They have no idea what it means to double clutch, and they have no idea how undeveloped the steering and suspension was back then. Driving those old cars is almost like driving a semi truck, but the new ones aren't even that hard.   > Well OK, it isn't really all that difficult but I bet you don't take that thing to work every day...     My dad had a 1950 Chevy when I had my learners permit. Not too bad to drive. Even my mother drove that car. It even had the modern push button on the dash to start it. You did not need the key if you left the switch in just the off position.

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 27 06:18PM -0400 >> All responses greatly appreciated.   >> Ivan Vegvary   > file:///C:/Users/pweick/Downloads/ETI_Feb77_ScopeTheIgnition_1b.pdf     That is a link to a file on your C: drive.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

whit3rd <whit3rd@gmail.com>: Oct 27 04:02PM -0700 On Wednesday, October 26, 2016 at 7:39:48 PM UTC-7, mike wrote: > On 10/26/2016 5:41 PM, whit3rd wrote:   {about displaying ignition on an oscilloscope]   > > minus 300 or so...)   > You have to be careful NOT to assume normal conditions when detecting > faults, which by definition, are NOT normal conditions. Stuff happens.   No '500V' scale on an oscilloscope is gonna burn up with a brief transient, nor can such transients get over 1 kV (the distributor or coil would arc). Probes, on the other hand, are at risk. You'd be best served by a suitable divider probe, they exist. Or, a few cheap parts and you've made one.   > A plug either fires or it doesn't. If it fires, the thing you > are interested in is the current.   Not true; probing the current is no less dangerous, stick with the V-versus-time and there's plenty of information present. More important, a dirty or worn spark plug might eventually pass the right amount of current, it matters what peak voltage it fires at, You'd be remiss in disregarding the voltage rise before conduction.     > Rule number one... > If it ain't broke, don't try to fix it using your expensive scope.   Gotta disagree strongly there. If you never 'scope out a working car, the diagnosis of a nonworking one is forever beyond your experience.

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Ivan Vegvary <ivanvegvary@gmail.com>: Oct 26 12:55PM -0700 Would like to hook up my newish Rigol 4 channel scope to analyze ignition in my 1948 Pontiac. Need hookup and safety information. Entering "lab scope ignition testing" etc. leads to hundreds of links but they are ALL automotive scopes e.g. Sun, Snap-On etc. They all claim the words "lab scope".   Could anybody suggest a better search term. All responses greatly appreciated.   Ivan Vegvary

"pfjw@aol.com" <pfjw@aol.com>: Oct 26 01:06PM -0700 On Wednesday, October 26, 2016 at 3:55:56 PM UTC-4, Ivan Vegvary wrote:

"pfjw@aol.com" <pfjw@aol.com>: Oct 26 01:09PM -0700 On Wednesday, October 26, 2016 at 3:55:56 PM UTC-4, Ivan Vegvary wrote:   > Could anybody suggest a better search term. > All responses greatly appreciated.   > Ivan Vegvary   file:///C:/Users/pweick/Downloads/ETI_Feb77_ScopeTheIgnition_1b.pdf   http://int.rigol.com/Applications/Car/?lc=EN   Would these help?   Peter Wieck Melrose Park, PA   I am not a member of any organized political party. I am a Democrat.   Will Rogers

Ivan Vegvary <ivanvegvary@gmail.com>: Oct 26 01:43PM -0700 Thank you PF. The link does tell me what is possible. I suppose by 'high pressure pdobe' they mean 'high voltage. Hookup diagrams would be nice to have. Of course the only electronics in a 1948 auto is the ignition system. Would love to look at 4 cylinders (8 total) at a time with the Rigol. I do have inductive pickups that I can salvage from timing lights.

mike <ham789@netzero.net>: Oct 26 03:11PM -0700 On 10/26/2016 1:43 PM, Ivan Vegvary wrote: > Of course the only electronics in a 1948 auto is the ignition system. > Would love to look at 4 cylinders (8 total) at a time with the Rigol. > I do have inductive pickups that I can salvage from timing lights.   Exactly what do you expect to see? What are you gonna do with the information when you get it?   Is the benefit derived from that worth the risk of blasting the front-end out of your scope?   What you see on the scope is likely to be more dependent on your probing technique than the signals present. When I experimented with monitoring fuel injection, I had trouble getting rid of the ignition noise so I could look at the injectors.   I have a Snap-On automotive scope with an input voltage rating of 500V with 30KV surge rating, whatever that means. I wouldn't go poking around aimlessly with that either. I'm sure it's completely safe...except when it isn't.   Keep your digital scope out of your car unless you really, really need to measure something that you can control to FIX something that's broke. Even the 12V...I guess it was 6V in 1948...electrical system is risky.   http://www.littelfuse.com/data/en/Application_Notes/an9312.pdf

Ivan Vegvary <ivanvegvary@gmail.com>: Oct 26 03:19PM -0700 On Wednesday, October 26, 2016 at 3:12:34 PM UTC-7, mike wrote: > broke. > Even the 12V...I guess it was 6V in 1948...electrical system is risky.   > http://www.littelfuse.com/data/en/Application_Notes/an9312.pdf   Thanks Mike, I thought if I could see all the ignition activity at the same time (or at least 4 at a time) I could look for anomalies and identify a poorly firing spark plug or semi-faulty wire.   Thanks for the cautionary note. Will heed.   Ivan Vegvary

whit3rd <whit3rd@gmail.com>: Oct 26 05:41PM -0700 On Wednesday, October 26, 2016 at 3:19:48 PM UTC-7, Ivan Vegvary wrote:   > I thought if I could see all the ignition activity at the same time (or at least 4 at a time) I could look for anomalies and identify a poorly firing spark plug or semi-faulty wire.     Yep, the low-voltage terminal of a spark coil does give that kind of info. You can identify (or so I'm told) variations in fuel mixture from cylinder to cylinder that way (higher breakdown voltage for rich fuel mixture). It takes a 500V scale for the o'scope, though ('low voltage' means +12 to minus 300 or so...). A transformer clip-on probe can trigger your 'scope from cylinder 1, which simplifies the analysis if your auto has a single coil for all the cylinders.

mike <ham789@netzero.net>: Oct 26 07:38PM -0700 On 10/26/2016 5:41 PM, whit3rd wrote: > On Wednesday, October 26, 2016 at 3:19:48 PM UTC-7, Ivan Vegvary wrote:   >> I thought if I could see all the ignition activity at the same time   (or at least 4 at a time) I could look for anomalies and identify a   poorly firing spark plug or semi-faulty wire. > A transformer clip-on probe can trigger your 'scope from cylinder > 1, which simplifies the analysis if your auto has a single coil for all the > cylinders.   You have to be careful NOT to assume normal conditions when detecting faults, which by definition, are NOT normal conditions. Stuff happens. It's best if that stuff doesn't happen when you're probing around with an expensive digital scope.   300V might be a fine number under normal circumstances, but, if a wire is bad and the plug fires at a much higher coil secondary voltage, the primary may also show a much bigger spike. And there's always the temptation to crank up the sensitivity to see some smaller wiggle on the trace. That may be a bad idea in this case.   A plug either fires or it doesn't. If it fires, the thing you are interested in is the current. After it arcs, the voltage will be determined by the plug and wire/coil resistance/inductance. High current >> fat spark >> good. Of course, that assumes that the current is all going thru the plug and not arcing to ground thru a crack in wire insulation.   If you have a clip-on current probe of known transient response, you can clip it on the coil output and look at the relative currents for all the cylinders. Properly insulated current probe designed for ignition service should be safe to use on your scope. If you try to move the probe to different plug wires, you'll probably see more variation in the coupling than in the actual signal.   It's a vintage car. If it runs, drive it proudly. If it runs like it has ignition problems, change the plugs. If that doesn't fix it, work your way back toward the battery. Run it in the dark and poke around the wires with a grounded probe to look for insulation faults. You can learn some interesting things by pulsing the coil with the engine off and listening to the coil. But, you can smoke the coil if you're not careful.   Rule number one... If it ain't broke, don't try to fix it using your expensive scope. Rule number two... If it IS broke, don't try to fix it using your expensive scope, except as a last resort.

Bruce Esquibel <bje@ripco.com>: Oct 27 10:22AM > I thought if I could see all the ignition activity at the same time (or at > least 4 at a time) I could look for anomalies and identify a poorly firing > spark plug or semi-faulty wire.   Ok but it still begs the question, why?   I can't see a set of new plugs, wires, cap, rotor, points and condenser running more than $50 dollars or so. I'd just replace everything and if you think something is wrong, look elsewhere.   You didn't say where and what condition this car is in, but time and money spent on a compression test and carb rebuild kit wouldn't be money ill spent. That and a timing light.   It's a novel idea but the scope isn't going to give you any more ideas than a good set of ears and eyes will.   -bruce bje@ripco.com

Ivan Vegvary <ivanvegvary@gmail.com>: Oct 27 06:08AM -0700 Thank you all. Scope will not be used on ignition. Car runs fine. Lesson(s) learned. Great group! Ivan Vegvary

Ralph Mowery <rmowery28146@earthlink.net>: Oct 27 10:58AM -0400 In article <nuskhl$4m5$1@remote5bge0.ripco.com>, bje@ripco.com says... > a good set of ears and eyes will.   > -bruce > bje@ripco.com   I agree that unless there is some odd problem, just replace everything for a few dollars insted of maybe messing up a scope that is a thousand or so dollars.   If there is an odd problem, maybe you could find someone that has one of the old Sun scopes.   For the old cars just see if you can find a timming light and dwell meter.

Jeff Liebermann <jeffl@cruzio.com>: Oct 27 08:57AM -0700 On Wed, 26 Oct 2016 12:55:53 -0700 (PDT), Ivan Vegvary >Entering "lab scope ignition testing" etc. leads to hundreds of links but they are ALL automotive scopes e.g. Sun, Snap-On etc. They all claim the words "lab scope".   >Could anybody suggest a better search term. >All responses greatly appreciated.   One of my customers uses one of these: <http://www.ebay.com/itm/Hantek-Virtual-Oscilloscope-8CH-Programmable-Generator-CE-Auto-Ignition-Probe-/140921187522> <http://www.hantek.com/en/ProductDetail_136.html> <http://www.hantek.com/en/ProductDetail_56.html>   The couplers are pricy: <http://www.ebay.com/itm/7pcs-HT-25-Auto-Ignition-Probe-For-Hantek-Automotive-Diagnostic-Oscilloscope-/140855478422> <http://www.ebay.com/sch/i.html?_nkw=8+ignition+probes> <http://www.hantek.com/en/ProductDetail_15_11165.html> Note that these are for "coil on plug" type engines, which are unlikely to be found on a 1948 Pontiac.   Maybe a coupler or ignition probe like one of these: <https://www.pinterest.com/ADPTraining/scope-1-automotive-engine-analyzer-oscilloscope/> <https://s-media-cache-ak0.pinimg.com/originals/2a/ee/3b/2aee3b18361772ee3ebbc98973cbf2e3.jpg>     -- 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

N_Cook <diverse@tcp.co.uk>: Oct 27 03:18PM +0100 With the built in temp comp diodes, 1 silicon in the N type and 5 Schotky in the P and mirror-reversed pinning . Owner put a short across one speaker line, magic smoke but other channel is normal. Internal emitter resistor .22R of the p type is now not .22R. I intend removing both , of the failed channel , to check out of circuit, but anyone jumpered in an external .2R in these circumstances and no further problems from cracked die etc as this R is part of the die? The datasheet I think , in fractured English, says the thermal safe operating over-current zone, for the built in .22R is deliberately lower than the Darlington itself. Anyone ever disentangled the "English" referring to deliberately? destroying the internal R so as to use an external emitter R,or is it just referring to doubling-up ? datasheet http://pdf1.alldatasheet.com/datasheet-pdf/view/38213/SANKEN/SAP15/+2732WUOYLI.OcU.utw+/datasheet.pdf

"pfjw@aol.com" <pfjw@aol.com>: Oct 26 01:00PM -0700 On Wednesday, October 26, 2016 at 11:50:33 AM UTC-4, MJC wrote:     > I suppose all saboteurs could be called a footnote :-)   At least they got a name.   Peter Wieck Melrose Park, PA   I am not a member of any organized political party. I am a Democrat.   Will Rogers

etpm@whidbey.com: Oct 26 01:52PM -0700 On Wed, 26 Oct 2016 13:00:30 -0700 (PDT), "pfjw@aol.com"   >On Wednesday, October 26, 2016 at 11:50:33 AM UTC-4, MJC wrote:   >> I suppose all saboteurs could be called a footnote :-)   Hey MJC, I just got your joke. Good one. Eric

MJC <gravity@mjcoon.plus.com>: Oct 26 11:44PM +0100 In article <rr521ch9g2p62kvdo1cqd7bsuojg05r9im@4ax.com>, etpm@whidbey.com says...   > >> I suppose all saboteurs could be called a footnote :-)   > Hey MJC, I just got your joke. Good one. > Eric   Thank you kindly!   Mike.

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Oct 26 07:09PM -0400 On 10/26/2016 11:50 AM, MJC wrote:   >> ... Nor were the Luddites much more than an historical footnote.   > I suppose all saboteurs could be called a footnote :-)   > Mike.   ;)   (*)   Cheers   Phil Hobbs   (*) "Saboteur" having originally meant "one who throws a wooden shoe (sabot) into the works".   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics   160 North State Road #203 Briarcliff Manor NY 10510   hobbs at electrooptical dot net http://electrooptical.net

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