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all2001@spambog.com (Wolfgang Allinger): Jun 19 06:11AM -0300 On 19 Jun 15 at group /sci/electronics/repair in article 530841b1-2bf4-457f-b82b-033ac2a08453@googlegroups.com   >> Hope my Ginglisch is understandable :)   >The sad thing Wolfgang is that your post was far better than some from >people whose native language is *supposed* to be English...   So these natives should try harder if even a bloody Kraut can outperform them :)     Saludos (an alle Vernünftigen, Rest sh. sig) Wolfgang   -- Wolfgang Allinger, anerkannter Trollallergiker :) reply Adresse gesetzt! Ich diskutiere zukünftig weniger mit Idioten, denn sie ziehen mich auf ihr Niveau herunter und schlagen mich dort mit ihrer Erfahrung! :p (lt. alter usenet Weisheit) iPod, iPhone, iPad, iTunes, iRak, iDiot

sam@repairfaq.org (Samuel M. Goldwasser): Jun 19 04:13PM -0400 Common (non-solid state/brushless) motors:   * Series DC motor, shunt DC motor, universal AC DC motor: Direction determined by relative wiring of stator and brushes.   * Permanent magnet motor: Direction determined by polarity of DC (or PWM etc.) input.   * 3 phase AC induction motor: Direction determined by phase relationship of 3 connections. Swap any two pairs to reverse motor.   * Single phase AC induction motor: Direction determine by relative phase of run and start windings during starting. Start winding only used during starting, cut off by centrifugal switch, starting relay, or other starting device. Main winding conencted directly to mains; start winding through capacitor or has different inductance/resistance to provide phase shift.   * Split phase AC induction motor: Direction determined by relative phase of two windings. Main winding conencted directly to mains; phase winding through capacitor or has different inductance/resistance to provide phase shift. Both windings powered when running.   There are many variations. :)   -- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html   Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

"Ralph Mowery" <rmowery28146@earthlink.net>: Jun 19 05:53PM -0400 "Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message news:87381n8nj8.fsf@repairfaq.org... > PWM etc.) input.   > * 3 phase AC induction motor: Direction determined by phase relationship > of 3 connections. Swap any two pairs to reverse motor.   One more thing to add to this that hapened where I worked. I don't recall the type of motor, but it was around 100 HP and had 4 sets of brushes and was driven by a varitable speed drive. Two people changed the brushes and said they did not touch the wires. It ran backwards. Several others looked at it and could not determin why it was running backwards. I went up and asked a few questions. I solved the problem for them. They had loosened the plate that holds the brushes and rotated it some to make it easier to replace the brushes. When they rotated it back, they had put it in the wrong place. By rotating it back to the correct position it ran the correct way.

"Rheilly Phoull" <rheilly@bigslong.com>: Jun 20 09:39AM +0800 The "ragged" wear and arcing would indicate open circuits in the armature windings. Put it back on the growler and drag a hacksaw blade across the gap in each slot. There should be an arc en you do that, if not most likely that winding is open.   Also I forgot to mention you have to rotate the armature after testing each slot.

"Rheilly Phoull" <rheilly@bigslong.com>: Jun 21 08:03AM +0800 wrote in message news:63e9c726-83d4-49e4-901a-45ae13b980a8@googlegroups.com...   > out that reversing the brushes did indeed reverse the direction of the > motor. We can't argue with success, but I still don't fully understand why > this is so. Can anyone please explain this to me? Thanks, Lenny   I don't have access to the growler any more but can't I use my Simpson? I'm thinking that I should have continuity between each of two segments 180 degrees apart. Is that correct? Lenny     Sure, use the Simpson on low ohms, once you have located a winding's bars go around and check each winding. Start with a winding with clean bar edges and then move up to the burnt ones. If you find an open or hi resistance check the crimp or soldering at those bars.

M Philbrook <jamie_ka1lpa@charter.net>: Jun 20 09:02PM -0400 In article <yMidnVbMHPbGYhjInZ2dnUU7-K-dnZ2d@westnet.com.au>, rheilly@bigslong.com says... > around and check each winding. Start with a winding with clean bar edges and > then move up to the burnt ones. If you find an open or hi resistance check > the crimp or soldering at those bars.   I use a LCR meter these days to check for shorts on the poles.   lot quieter than a growler. Use a megger for those HV leaks.   Jamie

"Arfa Daily" <arfa.daily@ntlworld.com>: Jun 19 02:31AM +0100 I currently have a Peavey PVX-P12 amp chassis on the bench. There was no audio at all from either the HF or LF digital output ICs. The IC in question has a 'go / mute / standby pin and this pin on both ICs is connected to a little control circuit. That in turn is driven by the "AC Detect" circuit on the power supply. This bit of circuitry is very straightforward, and comprises a bridge fed with AC from the line input, via a 0.47 uF 275 v ~ x-class cap. Across the output of the bridge, are two caps in parallel, shown on the schematic as being 22uF at 25 v working. But here's the thing. They are not shown as being polarised, nor is there any marking that I can see on the caps themselves, that indicate any polarity. They are surface mount and small - approx 3.6 x 2.6 x 1.8 mm - and look just like a typical sm ceramic cap. Pink-y glazed body with conventional 'end caps'. One of these two capacitors is short circuit. With it removed, everything returns to normal, and the amps both un-mute. The circuit only produces a few volts, and this is used to drive the LED in an opto via a 47 ohm R, the transistor side of the opto being the "AC Detect" signal that connects to the mute control circuit on the amp board.   So what type of caps are these ? They seem awfully small for any kind of solid dielectric non-polarised cap of that value, and that sort of voltage rating. I've had a look around at a few component supplier's offerings, and can't find anything that seems to match. I checked the capacitance of the one that isn't short, and it came up at 18 uF, so a bit low, but in the ballpark of what it says on the schematic. Given that these caps only seem to serve as the filter for the bridge output, and that there is only a few volts across them in normal operation, can anyone see any potential problems with replacing them with a pair of 'conventional' 22 uF 16 v polarised tants, obviously taking care to put them the right way round ?   Arfa

"Arfa Daily" <arfa.daily@ntlworld.com>: Jun 19 08:49AM +0100 "Phil Allison" <pallison49@gmail.com> wrote in message news:d1c37f77-0764-47d7-aa2c-872280577727@googlegroups.com... >> can't find anything that seems to match.   > ** I found lots - eg:   > http://www.newark.com/murata/grm32er61e226me15l/ceramic-capacitor-22uf-25v-x5r/dp/24R6350     Thanks, Phil. Oddly, I searched in Farnell, which is basically the same company as Newark, and these caps did not appear. But sticking the Murata part number into the Farnell search engine - there they are. Just goes to show that what I have always said - that Farnell's product searcher is useless - has been borne out again ... >> with replacing them with a pair of 'conventional' 22 uF 16 v polarised >> tants, obviously taking care to put them the right way round ?   > ** Should work fine.   Yeah, I thought so. The guy is hoping to use it tonight so I think I will just go with the tants   Arfa

"Arfa Daily" <arfa.daily@ntlworld.com>: Jun 19 09:04AM +0100 > Why would they have to be unpolarised? Just 2 paralleled together to get > the required capacitance. Any polarising mark on the SM carrier strip > perhaps     I don't think that they *do* have to be un-polarised, as such, given the ones that Phil has found. I think it's just because they *are*, if you see what I mean. To be honest, I never knew that you could get multilayer ceramics in such high values. Presumably, they don't go up as high as 47 uF which the designer felt he needed, so he just put 2 x 22 uF in parallel instead. As I said, the circuit is absolutely un-critical in that it only needs to produce a small amount of DC from the incoming mains to power the LED in the opto that produces the muting signal. Because of time constraints with ordering-in those ceramics, I think I'm just going to go with a pair of small tants, fitted to observe their polarity.   Arfa

N_Cook <diverse@tcp.co.uk>: Jun 19 12:00PM +0100 On 19/06/2015 09:04, Arfa Daily wrote: > just going to go with a pair of small tants, fitted to observe their > polarity.   > Arfa   So to get that capacity in that package , they must be seriously multi MLCC. Was it actually dead short or very low resistance. I suspect the usual metal migration failure mode of MLCC , then paralling-up just increases the chance of failure , for the circuit. Someone mentioned paralling ten , asking for trouble.

N_Cook <diverse@tcp.co.uk>: Jun 19 11:36AM +0100 On 19/06/2015 09:04, Arfa Daily wrote: > just going to go with a pair of small tants, fitted to observe their > polarity.   > Arfa   So to get that capacity in that package , they must be seriously multi MLCC. Was it actually dead short or very low resistance. I suspect the usual metal migration failure mode of MLCC , then paralling-up just increases the chance of failure , for the circuit. Someone mentioned paralling ten , asking for trouble.

"Arfa Daily" <arfa.daily@ntlworld.com>: Jun 20 02:10AM +0100 > So to get that capacity in that package , they must be seriously multi > MLCC. Was it actually dead short or very low resistance.   Very low resistance, I guess. Decimals of an ohm. Low enough for me to consider it to be 'dead short', anyway ...   Arfa

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jun 19 11:10AM -0400 On 06/19/2015 08:47 AM, Matthew Connor wrote:   >> Cheers   >> Phil Hobbs     > Dr. Hobbs: Thank you very much for your insight, sir! It's greatly appreciated! -Matthew   Just 'Phil' to colleagues. The fancy sig block is for SEO purposes. (It works great btw.)   Cheers   Phil Hobbs   -- 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

Jeff Liebermann <jeffl@cruzio.com>: Jun 19 08:23AM -0700 On Fri, 19 Jun 2015 05:46:13 -0700 (PDT), Matthew Connor   >Good morning, Jeff! Thank you so much for your insight. >My counter is a Lionel CD V-700 Model 6b, manufacture date 1962.   That's the same as what I have. Watch out for leaky D cell batteries. I nearly destroyed mine when Duracell's leaked.   >the counter was probably designed to survive a nuclear attack." >So I'm not quite sure that I'm understanding if what I did was >bad or not.   I would say it was a bad thing to tear it apart. You didn't mention if it was working before you attacked, so I question whether any of the work you've done was worthwhile or productive. If it was dirty, just clean the board. There's no reason to clean the component leads, or make it pretty unless you're installing a clear case and using it for show and tell.   The detrimental parts are: 1. The phenolic PCB is very sensitive to handling, soldering, and "cleaning". You could easily have ruined it. 2. The coatings that you removed are there to prevent the high voltage power supply from being shorted by water condensation and high humidity. By removing the coating (probably some type of conformal coating), you have removed that protection. However, not all C V-700-6b counters had coated PCB's. One of mine does, while the other does not. 3. Some of the old components are difficult to find, such as the neon regulator tube, but are at least available. Unsoldering these and is a bit of a risk. <http://www.surplustuff.com/radiolog.htm> 4. The rotary switch is a big of a reliability problem. If you bend the contacts more than once, they'll break.   The good news is that the device is very simple and has few components. It's made for easy repair, which is fairly easy. That's the origin of my bad joke about the counter surviving a nuclear attack.   Drivel: It's not really a counter, because it doesn't count, but I can't get out of the habit of calling it a counter.   >your suggestions into account as I move forward with my project. >I'll be trying the breath moisture thing right away. Thanks for >taking the time to educate an east coast newbie! :) -Matthew   The breath test is fairly simple and will usually indicate immediately if you have a problem. I haven't tried it on mine for a long time, but as I recall, one counter consistently failed when I took it out a cold garage, and brought it into a warm house. With moisture all over the counter, it didn't work until it warmed up. This is a rather severe test and I would not expect even a conformally coated PCB to survive a condensed moisture test. However, a simple breath test should give you a clue as to how sensitive the counter is to moisture. If you want to fix that, some wax based conformal coating around where the GM tube cable connects to the PCB should be a good start. The wax coatings are nice because they come off easily if you need to do some rework. Make sure the PCB is clean and degreased before coating or you will trap the moisture under the wax.       -- 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

Chuck <chuck@mydeja.net>: Jun 19 08:01AM -0500 >rocks may be more radioactive as well as concrete. Some green >glassware and some glazes on ceramics are radioactive. >Eric     If you happen to have any Pentax or Carl Zeiss Jena lens from the 60s that have turned yellow, they are a good radiation source for testing a Geiger counter.   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

John-Del <ohger1s@aol.com>: Jun 24 04:58PM -0700 > I returned them for a refund, but I only received a > refund for the items, not the shipping and handling costs.   > John       Buy from them all the time. Big selection, prices good and never had a problem with anything I bought from them.

jurb6006@gmail.com: Jun 24 06:09PM -0700 How much shipping ? Some places only charge actual. Others tack on some. some eBayeers make the shipping so high, which is not refundable in the event of a return, that it is not worth sending back. Of course in response, eBay charges its percentage on the shipping portion as well.   I wuld not go so far as to condemn a place for one thing. I did condemn one place but that was for two things. onbe wass a counterfeit IC, an STK I was hoping to be NOS. It wasn't, it failed ar the second power up. That didn't do it, and they did give a refund. What did it was later I ofund the 100 uF/35 volt lytics I ordered were 25 volts.   Sorry.   I've never had to send anything back to Digikey, but I like how they work except for one thing. TheyDO charge aqctual shipping and they do pack and box verynicely. Then you get your $100 order and the shipping was like $5.   I wonder ho they do manage that. Well not really, they must have a really well layed ut set of warehouses and perhaps a bunch of automation involved as well.   Thing to remember is they did not build it. I have no affiliation, but if they will at least take them back that os to the good. Now if they don't make a stivk with their vendor(s) and simply restock them and sell them to someone else that is a different story.

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