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Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Apr 30 07:23PM +0200 On 30-4-2018 8:41, Ivan Vegvary wrote:   > Need to replace a "button style" (Motorola MR2506) rectifier with a "stud mounted" one (Motorola 1N1190A) The stud mounted on has a higher rating. > Question: Data sheet says button battery cathode marked by "dot". Dot no longer visible on installed parts. Is it safe to assume that the wires from the transformer secondary lead to the Anode and the body of the "button style" (cathode) is pressed into the aluminum plate? > Thank you for your help.   Just put it in, and then load the charger with a 12 volt headlight. Then check polarity, and flip the rectifier connections if the polarity is wrong.

Ivan Vegvary <ivanvegvary@gmail.com>: Apr 30 10:40AM -0700 On Monday, April 30, 2018 at 10:23:34 AM UTC-7, Sjouke Burry wrote:   > Just put it in, and then load the charger with a 12 volt headlight. > Then check polarity, and flip the rectifier connections if the polarity > is wrong.   Thanks all !!! Problem solved. Disconnected good diode from circuit, tested and determined that the anode is connected to the transformer and the cathode is pressed on to the metal plate. Will order the 1N1190A stud bolt replacement. Inexpensive, probably less than the shipping cost. Thanks again !

John-Del <ohger1s@gmail.com>: Apr 30 10:54AM -0700 On Monday, April 30, 2018 at 1:40:48 PM UTC-4, Ivan Vegvary wrote:   > Thanks all !!! Problem solved. > Disconnected good diode from circuit, tested and determined that the anode is connected to the transformer and the cathode is pressed on to the metal plate. Will order the 1N1190A stud bolt replacement. Inexpensive, probably less than the shipping cost. > Thanks again !     Just make sure the diode you get is polarized the same. IIRC, those stud rectifiers were available with reverse polarity if ordered that way. Who knows if any of those made their way to the secondary parts market.

tabbypurr@gmail.com: Apr 30 11:25AM -0700 On Monday, 30 April 2018 18:40:48 UTC+1, Ivan Vegvary wrote:   > Thanks all !!! Problem solved. > Disconnected good diode from circuit, tested and determined that the anode is connected to the transformer and the cathode is pressed on to the metal plate. Will order the 1N1190A stud bolt replacement. Inexpensive, probably less than the shipping cost. > Thanks again !   In future you should keep at least 1 high current smpsu in your junk to get high i diodes from     NT

"Ian Field" <gangprobing.alien1@virginmedia.com>: Apr 30 09:00PM +0100 "Ivan Vegvary" <ivanvegvary@gmail.com> wrote in message news:fd181a50-dda3-4926-a0f8-5588c9cc5df7@googlegroups.com... > from the transformer secondary lead to the Anode and the body of the > "button style" (cathode) is pressed into the aluminum plate? > Thank you for your help.   In the UK, we have discount stores like Aldi & Lidl that do time limited offers, battery chargers come around from time to time and sometimes they're 6V capable.   The David Silver Honda parts specialist allegedly has 6V capable Honda branded Optimate chargers - but never on any of the occasions I tried to order one.

Rheilly Phoull <rheilly@bigslong.com>: May 01 08:46AM +0800 On 30/04/2018 8:39 PM, Ivan Vegvary wrote: > Reilly, both diodes have a removable lead going to the xformer. The bodies are press fit into a copper plate. Do I simply unplug and check for current direction with ohmeter?   Sounds like a half wave rectifier, there would be 3 wires from the tranny. If the diodes are the same you would need to make sure they were the same polarity as the previous diodes.

Fox's Mercantile <jdangus@att.net>: May 01 06:46AM -0500 On 5/1/18 6:13 AM, Unlisted wrote: > SELENIUM rectifier. Silicone diodes are far too flimsy and cant handle > the current load. Selenium rectifiers are made to handle all the current > you can pump thru them. and are made to be abused without failing.   Good Lord, what fucking rock have you been asleep under for the past fifty year?     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

John Robertson <spam@flippers.com>: Apr 30 10:56AM -0700 > Used its equivalent - it works.   > Peter Wieck > Melrose Park, PA   Peter, does that have a suitable breakdown voltage for 130 - 150VAC? I didn't bother sending the manufacturer my email address so they would send me the docs to verify. However the ad says it is suitable for LEDs and circuit boards, doesn't mention higher voltage applications.   For the OP be really sure to clean between the windings where the arcing occurred, you want to remove any sharp edges or points on the wire or any carbon residue. There are dialectic varnishes designed for higher voltages such as MG Chemicals Corona Dope:   https://www.mgchemicals.com/products/insulating-coatings/super-corona-dope-4226     John :-#)#

John-Del <ohger1s@gmail.com>: Apr 30 11:26AM -0700 > Any ideas ?   > Also, I am not all that worried about the boost end of it, ans I am not concerned with ground faults because I can just always run it off isolation. It will almost fit n that cabinet but not with the knob in front, and I don't want it on top. But then it might be ready for the dump anyway.   > Thanks in advance.   Remember the Mitsubishi deflection yokes that used to arc over on the PTVs? Back in the old days, I'd just kind of gently pick apart the area where the arcing occurred, clean as best I could, and dose it with several layers of thin cyanoacrylate. That stuff penetrates almost like Kroil. Of course, those windings were much thinner and easier to move around. Not advice really, just reminiscing.

tabbypurr@gmail.com: Apr 30 11:26AM -0700 On Monday, 30 April 2018 18:57:01 UTC+1, John Robertson wrote: > voltages such as MG Chemicals Corona Dope:   > https://www.mgchemicals.com/products/insulating-coatings/super-corona-dope-4226   > John :-#)#   removing every little trace of carbon is vital IME     NT

"pfjw@aol.com" <peterwieck33@gmail.com>: Apr 30 11:39AM -0700 On Monday, April 30, 2018 at 1:57:01 PM UTC-4, John Robertson wrote:   > didn't bother sending the manufacturer my email address so they would > send me the docs to verify. However the ad says it is suitable for LEDs > and circuit boards, doesn't mention higher voltage applications.   John:   I must admit I am not sure. I used its functional equivalent on a Hot Tub control board switching 240 VAC heater and 120 VAC pump circuits without any problems - but for the heater on one just failed this weekend. Not the board, the heater itself. I suspect that the material you linked might be more suitable given its brush applicator and specific prescribed uses.   > any carbon residue. There are dialectic varnishes designed for higher > voltages such as MG Chemicals Corona Dope:   > https://www.mgchemicals.com/products/insulating-coatings/super-corona-dope-4226   The 'thing' about AC arcing is that once an arc is struck, the plasma generated helps sustain it. Hard to strike, but once struck not hard to maintain if there is a source for the plasma. Just a few weeks ago, a large Norway maple tree behind us started rubbing against a 13,200 primary. Those arcs made 6-8 inches until sufficient of the tree was eroded that the distance eventually was too much. PECO took nearly a week to get to it as the heavy snow and wind that caused the condition in the first place did far more damage elsewhere. 90 houses around us were without power for 4 days. We were exceedingly lucky not to.   When PECO did come, they worked from our back yard, and I got 'the dope' on arcing from their engineer on-site.   Peter Wieck Melrose Park, PA

John Robertson <spam@flippers.com>: Apr 30 12:27PM -0700 > When PECO did come, they worked from our back yard, and I got 'the dope' on arcing from their engineer on-site.   > Peter Wieck > Melrose Park, PA   A Jacob's Ladder is an excellent example of how an AC or DC arc plasma, once started, can more than double its initial width as the plasma climbs up the wires...   https://www.youtube.com/watch?v=0ioHlYCmu_A   https://www.popsci.com/how-to-build-jacobs-ladder   I had one in my parents home where I had a fat 5KV Neon sign Xformer - which made nice fat arcs, but that was way back in the 60s...   John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Fox's Mercantile <jdangus@att.net>: Apr 30 03:45PM -0500 > Then I noticed that at the end, above where the line goes > in, it was arcing between the windings.   How does it do that? The voltage from one winding to the next is pretty small.   don't worry about carbon tracks, if you ppur this stuff <https://www.ebay.com/itm/152789446463> over the part that's arcing, the carbon will be encapsulated.   Give it 2-3 days to completely dry and get hard.   It if still arcs, throw it in the trash.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

jurb6006@gmail.com: Apr 30 01:52PM -0700 Thanks folks, I'll look into these options and try it.

Jeff Liebermann <jeffl@cruzio.com>: Apr 30 06:43PM -0700 On Mon, 30 Apr 2018 15:45:19 -0500, Fox's Mercantile <jdangus@att.net> wrote:   >don't worry about carbon tracks, if you ppur this stuff ><https://www.ebay.com/itm/152789446463> >over the part that's arcing, the carbon will be encapsulated.   I don't know how it's possible to arc between windings with only 117/220VAC. My guess(tm) is that there's arcing between the contact brush and the windings caused by a layer of filth on the windings or contact brush.   No way am I going to pay $18 for 2 oz of Q-Dope. Q-Dope is polystyrene disolved in MEK. <http://www.gcelectronics.com/order/msds/101.pdf> Make your own from packing peanuts and MEK: <https://www.youtube.com/watch?v=ANn6hti35Zc>   Maybe some anti-corona goo will provide some better arcing protection: <https://www.mgchemicals.com/products/insulating-coatings/super-corona-dope-4226> <https://www.amazon.com/MG-Chemicals-Corona-Liquid-Applicator/dp/B008OA7CAE>   Variac cleaning videos: <https://www.youtube.com/watch?v=5vKHOSpynM8> <https://www.youtube.com/watch?v=xPdIrzw2kko> <https://www.youtube.com/watch?v=Mbbght6HIxM> etc...   -- 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

Jeff Liebermann <jeffl@cruzio.com>: Apr 30 06:52PM -0700 On Mon, 30 Apr 2018 18:43:11 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote: (...)   This kinda sounds like the arcing problem as described. The arcing is from the winding to the carbon brush wiper:   Variac Repair using DeOxit: <https://www.youtube.com/watch?v=qRTKHNoiRQI>   However, I'm not sure that's such a great idea. It looks like he managed to burn up the Variac: <https://www.youtube.com/watch?v=po5Xxl_Syxg>     -- 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

jurb6006@gmail.com: Apr 30 08:26PM -0700 >"This kinda sounds like the arcing problem as described. The arcing is from the winding to the carbon brush wiper: "   No, the wiper was nowhere near it. It is either between the windings or from the windings to the core.   From what I see there are probably 100 turns, if not there must be at least 50. That means only a couple volts between each turn. This is not hopeful.   Since it all seems to be at the boost end, maybe I can eliminate that part and just have something that will cut the line voltage. It beats nothing.   There is another possibility, I could put the rectifiers back in the "isolation transformer" cabinet and use the DC supplies which are + - 90 volts to power a class D amp. I know they can get hairy to design like for high fidelity audio but for these lower frequencies it should not be all that difficult. Or I could tap off an existing class D amp before the output filter (except for certain Crowns et. al.)and use that to drive bigger transistors, set up a feedback attenuator to match the level and make a bigger output filter. It would be easier than designing from scratch. It would also automatically be isolated.   But honestly that is a pipe dream. Maybe I should just think about eliminating that part of the winding and hope the rest is alright. Seems like that would be the hottest part of the winding and would fail first, no ? For the amount of time I use it...   Soon, I'll take the cover off and have a closer look at this arcing. But I am sure it is not to the wiper.

tabbypurr@gmail.com: Apr 30 08:53PM -0700 > There is another possibility, I could put the rectifiers back in the "isolation transformer" cabinet and use the DC supplies which are + - 90 volts to power a class D amp. I know they can get hairy to design like for high fidelity audio but for these lower frequencies it should not be all that difficult. Or I could tap off an existing class D amp before the output filter (except for certain Crowns et. al.)and use that to drive bigger transistors, set up a feedback attenuator to match the level and make a bigger output filter. It would be easier than designing from scratch. It would also automatically be isolated.   > But honestly that is a pipe dream. Maybe I should just think about eliminating that part of the winding and hope the rest is alright. Seems like that would be the hottest part of the winding and would fail first, no ? For the amount of time I use it...   > Soon, I'll take the cover off and have a closer look at this arcing. But I am sure it is not to the wiper.   if it's a small section of winding, how hard is it to rewind that bit?

John Robertson <spam@flippers.com>: Apr 30 09:14PM -0700 > There is another possibility, I could put the rectifiers back in the "isolation transformer" cabinet and use the DC supplies which are + - 90 volts to power a class D amp. I know they can get hairy to design like for high fidelity audio but for these lower frequencies it should not be all that difficult. Or I could tap off an existing class D amp before the output filter (except for certain Crowns et. al.)and use that to drive bigger transistors, set up a feedback attenuator to match the level and make a bigger output filter. It would be easier than designing from scratch. It would also automatically be isolated.   > But honestly that is a pipe dream. Maybe I should just think about eliminating that part of the winding and hope the rest is alright. Seems like that would be the hottest part of the winding and would fail first, no ? For the amount of time I use it...   > Soon, I'll take the cover off and have a closer look at this arcing. But I am sure it is not to the wiper.   I trust the variac is grounded, so this may be an arc to the case...or failing insulation on the power cord. How OLD is this variac anyway?   John :-#(#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Fox's Mercantile <jdangus@att.net>: Apr 30 11:54PM -0500 On 4/30/18 11:14 PM, John Robertson wrote: > I trust the variac is grounded, so this may be an arc to > the case...or failing insulation on the power cord. How > OLD is this variac anyway?   Since it's on the "hgh" (boost) of the variac, He's got between 120=135 vac to gound at that point.   And knowing Jurb, it's probably something he fished out of a dumpster 30 years ago. He's already admitted to "fixing" it twice already. I doubt he did a good job either time.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

tabbypurr@gmail.com: Apr 30 10:20PM -0700 On Tuesday, 1 May 2018 05:55:01 UTC+1, Fox's Mercantile wrote: > a dumpster 30 years ago. > He's already admitted to "fixing" it twice already. > I doubt he did a good job either time.   Variacs are all (or almost all) many decades old.     NT

John Robertson <spam@flippers.com>: Apr 30 11:22PM -0700 >> I doubt he did a good job either time.   > Variacs are all (or almost all) many decades old.   > NT   Not all are decades old:   https://www.circuitspecialists.com/variac-tdgc2-2.html   John ;-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Fox's Mercantile <jdangus@att.net>: May 01 06:42AM -0500 >> I doubt he did a good job either time.   > Variacs are all (or almost all) many decades old.   > NT   Not off them are fished out of a dumpster either.   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Unlisted <unlisted@nomail.com>: May 01 06:13AM -0500 On Sun, 29 Apr 2018 23:41:23 -0700 (PDT), Ivan Vegvary >I need the 6 volt capability for my vintage motorcycle.   >Need to replace a "button style" (Motorola MR2506) rectifier with a >"stud mounted" one (Motorola 1N1190A) The stud mounted on has a higher rating.   For a battery charger, you do NOT want a silicone rectifier, you want a SELENIUM rectifier. Silicone diodes are far too flimsy and cant handle the current load. Selenium rectifiers are made to handle all the current you can pump thru them. and are made to be abused without failing.

"Ron D." <ron.dozier@gmail.com>: Apr 30 03:50PM -0700 It's not likely to protect the whole house.   Probably, your best bet is a whole house surge suppressor with a warranty. There is really no point without a protected equipment warranty. Many times, you need the receipt. A whole house suppressor typically connects to a breaker.   The "surge stopper" products from Linear Technology now Analog Devices seem to be very good, but it's something that's designed into the low voltage power supplies.   I had extremely good luck by using a line conditioner from ONEAC, now Powervar and an ISOBAR suppressor. One particular computer had a 17 year stint before it was upgraded. The SCSI drives lasted 17 years. The floppy failed (mechanical) and dust created ventilation issues.   It initially was used on an obsolete system and the failures were pretty much the same. Floppies and fans.   The same system was continued on the new upgraded system. It's not a UPS. Rebonding the neutral cleans up the ground. See some youtube videos on the Powervar concept and actual videos. They don't like the ISOBAR.   In an APC surge suppressor I had, that failed because a thermal fuse blew, allowed the unprotected AC to power the devices. yes, a light indicated that the outlets were unprotected, but who looks at these.   There are systems that take this "concept" and do it at the power entry panel.   Inherently, the AC distribution in the US is flawed. Hospitals and radio transmitting stations may use a better method which totally separates signal ground from a ground fault. Orange outlets have an isolated ground which allows two independent grounds to be connected. Ideally every duplex outlet should be wired directly to the panel.   You then have green and green/Yellow grounds. one will never see fault currents.   You have both common mode and normal mode surges to deal with as well as high frequency issues. The transformer fixes the high frequency issues because it's hard to couple that across the windings.   In a daisy chained outlet, a surge could raise the ground potential of everything connected to the chain and stuff that uses the ground for communication will see different levels. If each had a signal ground to the panel, the surge would raise everything in the house because of the surge path and the signal grounds would all be at the same potential.   Communication between equipment is sometimes done via the ground connection and that's where the re-bonding of the neutral helps dramatically.   It is best to stop noise and surges at the source too. A Carrier HVAC system polluted the AC line when it was on. X-10 devices would not work until a line filter was installed at the furnace. I also felt it was wise to add a bidirectional transorb (TVS bi-directional diode) on the 24 VAC supply. There is a low voltage fuse, so if the Transorb should short the fuse should blow.   Basic surge suppression costs the manufacturer a lot of money for $10.00 or less of parts. One experience highlights the problem. A multichannel analyzer (an instrument that bins pulses) that we had the schematic for, but lacked the expertise to fix failed. he MFR offered board/exchange type of repair. I noticed that there was absolutely no protection for the low-end model costing about $5000.00 USD and the board repair was about $1000.00.   I asked the manufacturer and got the following. We specify that the product needs 120 VAC, 60 Hz. Surges violates that spec, so it's your problem.   One thermocouple scanner would break in the presence of 1000 W IR lamps used for heating. The schematic showed a complete voltage regulator, but the product was shipped with that unpopulated. Adding two parts and not the full design fixed the failure issue.

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