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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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