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jurb6006@gmail.com: Apr 30 05:50AM -0700 Got this nice 0-140 5 amp variac that started arcing. Iunplugged it immediately of course.   It had been repaired before. When I first got it the wire feeding from the AC input had pulled the turn of the winding off, soldering took care of that. There was a little catch right at that point but it wasn't bad. Months, maybe about a year ago that "catch" got worse and I reworked it, tightening up the winding and making sure it was smooth. It was fine.   Then about last week I was using it to boost voltage to a car battery charger to feed something a tad over its usual output, which was working fine. And no overload at all, the drain was about 2.5 amps at 16 volts or so, so that was well within spec for the variac. Later I turned it down because it was time to test the UUT with lower voltage. (this is an intermittent overheating problem in the DC/DC convertor of an AC/DC version of the Tek 422)   Then I noticed that at the end, above where the line goes in, it was arcing between the windings.   I don't have nor want to find the magnet wire to rewind or partially rewind this thing. Is there a chemical solution to this problem ? (pun intended)   Perhaps our resident thaumaturge Jeff Lieberman has some idea, or anyone. I don't use it enough to buy another one but when I need variable AC I need variable AC. I might have to add some boost/buck transformers to my newly kludged bohungus isolation transformer. It even has a fan.   http://usr.audioasylum.com/images/7/71823/badazzis01.jpg   As you can see there is plenty of room for a few smaller transformers, but I would need them to be able to handle the current of the main one, right ? Otherwise an overload could be a catastrophe, and I have had enough of those in my life.   But is there a way to fix the variac ? I'm thinking a solvent, then enamel, then filing it down for the wiper to contact and ??? Maybe. I don't know if I can find such chemicals, or if they even exist. And how would I keep the windings on place once they're stripped ?   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.

tabbypurr@gmail.com: Apr 30 06:04AM -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.   Variacs are never ready for the dump. If you can get all traces of the carbon out from the gap, you're most of the way there. If not, and I expect you won't, I'd cut the wire and unwind half a turn each side. Put a turn of new wire on & solder its ends to the old ends where they're not in the way. With 2 half turns out the way it should be easier to remove any carbon.     NT

"pfjw@aol.com" <peterwieck33@gmail.com>: Apr 30 06:17AM -0700 http://www.directindustry.com/prod/electrolube/product-6210-169678.html?utm_source=ProductDetail&utm_medium=Web&utm_content=SimilarProduct&utm_campaign=CA   Used its equivalent - it works.   Peter Wieck Melrose Park, PA

N_Cook <diverse@tcp.co.uk>: Apr 30 05:33PM +0100 > 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.   Does it have the correct width of brush? it must not be able to contact more than 2 turns at any time. The proper ones look suspiciously unmanly for the job.

Ivan Vegvary <ivanvegvary@gmail.com>: Apr 29 11:41PM -0700 Fixing old car battery charger. Do not want to buy new one because 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. 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.

Mike S <mscir@yahoo.com>: Apr 30 12:05AM -0700 On 4/29/2018 11:41 PM, 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.   Do you know the make and model of the charger?

Rheilly Phoull <rheilly@bigslong.com>: Apr 30 04:02PM +0800 On 30/04/2018 2:41 PM, 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.   Only 1 transformer wire goes to the diode, the other elsewhere probably an output terminal.

John-Del <ohger1s@gmail.com>: Apr 30 04:34AM -0700 On Monday, April 30, 2018 at 2:41:26 AM UTC-4, 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.   The couple I putzed around with had two rectifiers. If there's another, check that. In any case, the cathode should go towards the positive lead.

Ivan Vegvary <ivanvegvary@gmail.com>: Apr 30 05:32AM -0700 Mike, the model is a Schauer CR612 2 button diodes. Case bonded to copper plate, lead goes to xformer. On replacement diode (1N1190A) case is cathode.

Ivan Vegvary <ivanvegvary@gmail.com>: Apr 30 05:39AM -0700 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?

tabbypurr@gmail.com: Apr 30 06:00AM -0700 On Monday, 30 April 2018 07:41:26 UTC+1, 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.   can you not work it out by following wires & using a multimeter? Old chargers are exceedingly simple.     NT

jaugustine@verizon.net: Apr 30 08:08AM -0400 Hi, Recently my electric meter was replaced with a "Smart Meter". I realized that it must have surge protection for it's sensitive electronics.   Does this surge protection also help protect what is inside my house? Note: I have many surge protectors in various outlets.   Thank You in advance, John

N_Cook <diverse@tcp.co.uk>: Apr 30 01:24PM +0100 > Thank You in advance, John   Depends what you mean by surge, loss of neutral in the local 3-phase supply, lightning strike on a local supply line or transformer, or a more distant lightning strike.

tabbypurr@gmail.com: Apr 30 05:58AM -0700 > Recently my electric meter was replaced with a "Smart Meter". > I realized that it must have surge protection for it's sensitive > electronics.   why? Most PSUs don't.   > Does this surge protection also help protect what is inside > my house? Note: I have many surge protectors in various > outlets.   then you've spent your money adding a fire risk with no gain.     NT

whit3rd <whit3rd@gmail.com>: Apr 29 03:50PM -0700 On Sunday, April 15, 2018 at 9:30:31 PM UTC-7, Mike S wrote: > On 4/15/2018 8:30 PM, mike wrote:   > I was thinking of building a simple voltage/current regulator, and > wondering how much current would be spent in the ct.   Yeah, for battery powered gizmos, that's important. The easy solution is a funny chip that has a builtin current regulator, and has (as well as current limit) thermal protection (when mounted thermally to the LED parts).   Look on eBay for AMC7135 (about 1W delivered to an LED, use two or three in parallel for higher power lamps).. This is a good solution for a 4.2V battery input, which a power-wasting resistor can never improve on. Alas, battery and LED options must be driven by the choice of such a chip.

Mike S <mscir@yahoo.com>: Apr 29 11:12PM -0700 On 4/29/2018 3:50 PM, whit3rd wrote: > for a 4.2V battery input, which a power-wasting resistor can never > improve on. Alas, battery and LED options must be driven by the > choice of such a chip. $3 for 10! 10pcs AMC7135 350mA LED driver SOT-89 Thank you!

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