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KenW <ken1943@invalid.net>: Nov 17 08:43AM -0700 On Tue, 17 Nov 2020 09:10:11 -0500, "J.B. Wood" >material came from a leaky battery. I cleaned it off with rubbing >alcohol and the VOM once again seems to be working reliably. Has anyone >had a similar problem? Thanks for your time and comment. Sincerely,   Leaky batteries can be a big problem. Of course we forget to keep checking them. Every brand will leak, but the problem is finding out which is worse. Where I worked before I retired we got Duracell from a local hardware store. I really think they were a knocked off brand ! I have used Duracell the last couple of years and have been happy with them although most brands are within price range and work just as well. They die in my remotes well before any leakage can happen.     KenW

"J.B. Wood" <arl_123234@hotmail.com>: Nov 17 09:10AM -0500 Hello,   I had been having a recurring problem with a model WV-38A RCA VOM that I built from a kit way back in the day. For resistance measurements it uses 4 AA cells and 1 D cell. Over the last couple of years sometimes it worked fine and at other times the meter wouldn't budge, regardless if voltage, current or resistance was to be measured. I couldn't find anything amiss either- no blown fuse, broken circuit board traces or faulty or oxidized wafer switch contacts. I spotted some green (apparently conducting) material on a circuit board trace near a battery holder that had also migrated to other parts of the board. I think the material came from a leaky battery. I cleaned it off with rubbing alcohol and the VOM once again seems to be working reliably. Has anyone had a similar problem? Thanks for your time and comment. Sincerely, -- J. B. Wood e-mail: arl_123234@hotmail.com

"Peter W." <peterwieck33@gmail.com>: Nov 17 06:59AM -0800 A friend of mine brought over his ADT pushbutton panel the other day, reporting it "not working". It is fed from the back either by a 4.5V power-supply (wall-wart) or 3 x AA batteries in a pocket between the body and the wall-mount. Two things had happened: a) The little SMT power-jack had pulled away on two of the four tabs. That was a quick fix. b) In some previous time, one of the batteries had leaked and there was a large build-up of green salts concealed under the batteries.   He had installed new batteries, but the salts had bridged connections, causing them to short. I used an electric drafting eraser and dental picks to get all the corrosion out and soldered over the traces. It works. NOTE: Those salts are deliquescent - meaning that they attract water out of the air - so no surprise on the migration.   Peter Wieck Melrose Park, PA

Chuck <chuck445@yahoonospam.com>: Nov 16 01:50PM -0500 I've been reading about dimmers here and thought I would try dimming my outdoor LED lights with one of the Chinese 12-24VDC 30A PWM dimmers found on eBay and elsewhere. The lights are running at 12VDC and consume 8.5 A. Dimmer was installed, but noticed right away that it was very warm. In an hour, almost too hot to touch. Should not have been, not at the current levels I noted. After several hours, it began to smoke and burn out. In the meantime, lights went to full brightness and probably then some. Needless to say, the only way I'll be using any more of these is with an in line fuse as well. Of course, the dimmer doesn't have one inside.

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Nov 16 02:37PM -0500 On 11/16/20 1:50 PM, Chuck wrote: > probably then some.  Needless to say, the only way I'll be using any > more of these is with an in line fuse as well.  Of course, the dimmer > doesn't have one inside.   I sure wouldn't use one even with a line fuse.   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510   http://electrooptical.net http://hobbs-eo.com

"ohg...@gmail.com" <ohger1s@gmail.com>: Nov 16 11:48AM -0800 On Monday, November 16, 2020 at 1:51:06 PM UTC-5, Chuck wrote: > probably then some. Needless to say, the only way I'll be using any > more of these is with an in line fuse as well. Of course, the dimmer > doesn't have one inside.   I'm sure it's capable of 30 amps - for a minute at most. Sounds like typical Chinese overestimation. I remember a guy who brought what he insisted was a 1000W amplifier in for repair (said so on the box). I showed him how it drew 125W max off the line. I guess maybe it could do that 500W for a thousand of a second as the rail filters discharged into a 2 ohm speaker.

Chuck <chuck445@yahoonospam.com>: Nov 16 08:23PM -0500 >> more of these is with an in line fuse as well. Of course, the dimmer >> doesn't have one inside.   > I'm sure it's capable of 30 amps - for a minute at most. Sounds like typical Chinese overestimation. I remember a guy who brought what he insisted was a 1000W amplifier in for repair (said so on the box). I showed him how it drew 125W max off the line. I guess maybe it could do that 500W for a thousand of a second as the rail filters discharged into a 2 ohm speaker.   I did a little research today. I actually have/had two of these dimmers. They're all over the net. I had one that seemed to work fine (also claimed 30 A) and then I just got this other one I had all the trouble with. They look almost identical except the most recent one has an amber plastic cover that covers the screw inputs. I decided to disassemble them both. Circuit boards are different. With the one that never heats much, there is a much larger transistor than the one that burned. There are other differences too, but really don't know without going back to the images I took. So, even though they looked nearly identical, they weren't. Why would they decide to change something to the inferior when they had a working unit that was more capable beats me unless they were trying to save a few cents.   I've never trusted the Chinese stuff. I've unknowingly had their transistor substitutes in the past that never lasted as long as a Japanese equivalent. I also see 30V, 20 A switching supplies with variable voltage all over the place too, but darned if I'm ever going to buy one.

dplatt@coop.radagast.org (Dave Platt): Nov 16 02:39PM -0800 >Why all this and not have a blanket that simply works? Not for a single >season, but for years like they once had. Beats me.   It is, unfortunately, "the race to the bottom". Price and features drive sales; long-term reliability does not.   Sunbeam (and most other brands) thus have an incentive to "buy cheap", from companies which are skilled at building stuff which will last _just_ long enough. They count on most of the devices being out of warranty by the time they fail, and on most consumers being unwilling to go to the trouble and expense of keeping receipts and asserting their warranty rights. That way, they get to sell you cheap things every couple years, and collect a small profit each time, rather than sell you something once every 10 years for only a slightly higher profit.   Sadly, it shows the truth of an old rule of thumb. "When somebody asks 'Why X, it doesn't seem to make sense', the answer is most probably 'Money'."

Eli the Bearded <*@eli.users.panix.com>: Nov 16 07:37PM This might become less of an issue in the future as more things switch to standardizing on USB connections, but there's going to be a long time before that's everywhere. So, for the problem of Device A has a small barrel plug (female) and the power adapter for Device A going missing (or the cord breaking), getting a power adapter for Device B with the same voltage / amperage specs but a different connector working with Device A: what good options are there?   I've got an audio device (Device A) that needs a very simple 5v 0.5A DC, and I've got several wall warts that can provide 5v DC 0.5 or more A. But none of them have a matching co-axial barrel connector.   In the past I've solved this by buying pairs of connectors and replacing both sides at once. This has worked, but the cord strain-relief I build is not as good as factory so the cords fail faster. In the present case, the cosmetics would be pretty bad.   Maybe somebody sells inexpensive assortments of barrel connector to USB cords? Other ideas?   Elijah ------ used up his stash of old Radio Shack connector pairs

Fox's Mercantile <jdangus@att.net>: Nov 16 02:22PM -0600 On 11/16/20 1:37 PM, Eli the Bearded wrote: > This has worked, but the cord strain-relief I build > is not as good as factory so the cords fail faster.   I back fill the connectors with hot melt glue.   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

whit3rd <whit3rd@gmail.com>: Nov 16 12:29PM -0800 On Monday, November 16, 2020 at 11:37:16 AM UTC-8, Eli the Bearded wrote:   > the cosmetics would be pretty bad.   > Maybe somebody sells inexpensive assortments of barrel connector to USB > cords? Other ideas?     Sometimes thrift stores are well-stocked with adapters, and prices aren't too high to just... buy an assortment on speculation.   As for strain relief, you can get fusion tape (rubbery stretch-and-wrap stuff that becomes a solid blob) wrapped around the hand-soldered connection, and an overall layer of heatshrink tubing, which replicates most of the mechanical advantages of molded connectors, and is just AMAZINGLY ugly. And, it works.

Eli the Bearded <*@eli.users.panix.com>: Nov 16 10:14PM >> cords? Other ideas? > Sometimes thrift stores are well-stocked with adapters, and prices aren't too > high to just... buy an assortment on speculation.   Another option I've used in the past. The two thrift stores with good electric part selections that I used to go to have both closed. "Thrift Town" is where I used to buy my computer monitors, but when I needed another one last month, I was forced to buy new. The largest of the local Good Wills, the one that had an actual computer department, has also closed. The smaller ones haven't had the selection.   > connection, and an overall layer of heatshrink tubing, which > replicates most of the mechanical advantages of molded connectors, and > is just AMAZINGLY ugly. And, it works.   I'm not familiar with "fusion tape", but maybe I should be. For this particular device, however, my wife is unlikely to be pleased with "AMAZINGLY ugly." That's also why I'm reluctant to add a connector to this.   Elijah ------ does still has a decent furniture thrift store near by

dplatt@coop.radagast.org (Dave Platt): Nov 16 02:42PM -0800 In article <d4057b95-b86d-4540-93d0-6062a2832a44n@googlegroups.com>, >becomes a solid blob) wrapped around the hand-soldered connection, and an overall >layer of heatshrink tubing, which replicates most of the mechanical advantages of >molded connectors, and is just AMAZINGLY ugly. And, it works.   Yeah, those usually end up in the "My eyes! The goggles do _nothing_!" category of ugliness... and, yeah, they're sturdy enough that the fusion, the strain relief, the protected solder joint, and the whole wiring job will usually outlive the one who made it.

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