sci.electronics.repair@googlegroups.com

Google Groups

"NewsDemon" <mark_zacharias@sbcglobal.net>: Oct 20 09:19PM -0500 "M Philbrook" <jamie_ka1lpa@charter.net> wrote in message news:MPG.30860c64b3bcb2ed989d2d@news.eternal-september.org...   >> Thanks   > sounds like a cap reforming..   > Jamie   Nope. Bad connection somewhere. Solder connection, problem with a connector, etc.   Mark Z.

"NewsDemon" <mark_zacharias@sbcglobal.net>: Oct 20 09:09PM -0500 "M Philbrook" <jamie_ka1lpa@charter.net> wrote in message news:MPG.30860c64b3bcb2ed989d2d@news.eternal-september.org...   >> Thanks   > sounds like a cap reforming..   > Jamie   Nope. Bad connection somewhere. Solder connection, problem with a connector, etc.   Mark Z.

"NewsDemon" <mark_zacharias@sbcglobal.net>: Oct 20 09:15PM -0500 "M Philbrook" <jamie_ka1lpa@charter.net> wrote in message news:MPG.30860c64b3bcb2ed989d2d@news.eternal-september.org...   >> Thanks   > sounds like a cap reforming..   > Jamie   Nope. Bad connection somewhere. Solder connection, problem with a connector, etc.   Mark Z.

N_Cook <diverse@tcp.co.uk>: Oct 20 08:54PM +0100 On 20/10/2015 12:52, Michael A. Terrell wrote: > the loading on their servers. There is also an area with a lot of old > electronics and computer magazines you can read online, or download.   > <https://archive.org/details/electronicsmanuals?&sort=-downloads&page=6>   Are you aware of a widget/app to cross-compare an index of paper manuals against the main www resources, to determine what needs scanning in and uploading somewhere , so I can safely dump the paper-based repeats ?

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 20 06:56PM -0400 N_Cook wrote:   > Are you aware of a widget/app to cross-compare an index of paper manuals > against the main www resources, to determine what needs scanning in and > uploading somewhere , so I can safely dump the paper-based repeats ?     There are currently too many separate archives of manuals, so hang on to the paper manuals for now. It may take another decade for the volunteers to scan and process all of those manuals. If you don't want, or need them, put them on Ebay. Collectors like original manuals to go along with equipment that is to go into a museum.   BTW, Archive.com has a collection of the old GE Ham News publications: https://archive.org/details/GEHamNewsVol18No1   Also, issues of 73 magazine: https://archive.org/details/73-magazine

Michael Black <et472@ncf.ca>: Oct 20 07:18PM -0400

N_Cook <diverse@tcp.co.uk>: Oct 21 08:30AM +0100 On 20/10/2015 23:56, Michael A. Terrell wrote: > https://archive.org/details/GEHamNewsVol18No1   > Also, issues of 73 magazine: > https://archive.org/details/73-magazine   If only there was indexes constructed of all the main repositries, rather than search boxes, that would be a great help. Another factor is scanned-in incomplete manuals, not mentioned on the site. I downloaded one of elektrotanya last week that was a revision manual and only one small part of the schematic

Cursitor Doom <curd@notformail.com>: Oct 20 06:11PM On Tue, 20 Oct 2015 08:17:35 -0700, ggherold wrote:   >> >> >> > gghe...@gmail.com wrote: >> >> >> > > Hi all, I found this thing.. see pictures   >> >> >> > > https://www.dropbox.com/sh/sxd1cq8qbdyali4/ AAA6O9NqKQPvbX4QLzNAK-Vaa?dl=0 > low voltage windings. It could also be that the tube is dead. > I'll try with my tractor at home tonight.   > George H.   Be a lot simpler to just to use one half of the tranny and use the back EMF from interrupting the circuit instead. Breaking the current through the longest winding should give enough of a spike to see if the lamp flashes.

Cursitor Doom <curd@notformail.com>: Oct 20 06:16PM > Might be as simple as a neon strobe head...   Yes, but if it's a neon type you might as well bin it; they're so weak as to be virtually useless. I don't think this one is though, from what I can make out in the pictures.

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 20 08:01PM +0100 <ggherold@gmail.com> wrote in message news:aa224646-0b5f-4e79-8e12-895f8a277660@googlegroups.com... >> say a >> 9 volt battery? A filament transformer maybe?   > 9V battery and transformer? (how does that work?)   When you touch the battery across the low voltage winding, it builds up lines of magnetic flux around the core - when you break the current, the lines of flux collapse onto the core and induce a high voltage spike in the big winding.   Most 9V batteries are very low energy density and won't keep up the current through a low voltage winding - and doing that wouldn't serve any useful purpose anyway.   Hook one wire of the low voltage winding to one battery terminal, then hook a loose length of wire to to the other end of the winding and just flick it on the other battery terminal.   You might get a small back emf spark as you break the primary current, but you should be able to rig a gap for a half-decent spark from the big winding.

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 20 08:04PM +0100 <ggherold@gmail.com> wrote in message news:1fd8c44b-87be-47ae-9770-2c1e10a6ecd6@googlegroups.com... > (I don't have enough current to get any significant voltage across the low > voltage windings. It could also be that the tube is dead. > I'll try with my tractor at home tonight.   If you're trying it with a 9V radio battery - they can't shift much current.   One of those 6V 996 lantern batteries with the springs on top would stand more chance.

Cursitor Doom <curd@notformail.com>: Oct 20 09:12PM On Tue, 20 Oct 2015 20:01:39 +0100, Ian Field wrote:   >>> >> > gghe...@gmail.com wrote: >>> >> > > Hi all, I found this thing.. see pictures   >>> >> > > https://www.dropbox.com/sh/sxd1cq8qbdyali4/ AAA6O9NqKQPvbX4QLzNAK-Vaa?dl=0   > You might get a small back emf spark as you break the primary current, > but you should be able to rig a gap for a half-decent spark from the big > winding.   The coil from a relay might be a better idea than a tranny. Some of those have a great many windings of fine gauge wire which would put less of a load on a 9v battery. I've got some here showing over 400 ohms resistance.

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 20 10:16PM +0100 "Cursitor Doom" <curd@notformail.com> wrote in message news:n06aoo$8o2$1@dont-email.me...   > The coil from a relay might be a better idea than a tranny. Some of those > have a great many windings of fine gauge wire which would put less of a > load on a 9v battery. I've got some here showing over 400 ohms resistance.   Back emf is good - but a step up ratio is *MUCH* better.

ggherold@gmail.com: Oct 20 07:01PM -0700 On Tuesday, October 20, 2015 at 11:56:17 AM UTC-4, Tom Miller wrote: > > I'll try with my tractor at home tonight.   > > George H.   > Just be careful. Getting hit with the HV can really hurt.   I didn't have time to play with it this evening. (my night to take my daughter to dance, and raining when I got home. Tomorrow, as long as the sun doesn't set too soon. :^)   HV, not to worry, I've been bitten several times, and have a healthy respect. George H.

Bob Engelhardt <BobEngelhardt@comcast.net>: Oct 20 11:24PM -0400 As others have said, it's an old, primitive, cheap timing light: http://amccars.net/cgi/yabb2/YaBB.pl?num=1313093243

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Oct 21 01:04AM -0400 > What sort of voltage do I apply to the leads?   > Thanks, > George H.   Looks like a fairly powerful flashlamp inside--it might be the business end of one of those old photo flash units that ran off a 300V dry cell     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

"Tom Miller" <tmiller11147@verizon.net>: Oct 21 01:24AM -0400 "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message news:qMqdnSIxRKFQgbrLnZ2dnUU7-QednZ2d@supernews.com...   > Cheers   > Phil Hobbs   > --   No, they just had a Neon tube. You had to enhance the timing mark on the balancer with white chalk. It really would not work outside in sunlight. They were the cheapest timing light one could buy then. Now they use Xenon flash tubes and inverters/storage caps.   I would venture a guess that unit was made in the 60's or earlier.

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Oct 21 02:09AM -0400 On 10/21/2015 01:24 AM, Tom Miller wrote: > They were the cheapest timing light one could buy then. Now they use > Xenon flash tubes and inverters/storage caps.   > I would venture a guess that unit was made in the 60's or earlier.   Why go to the trouble of making that huge helical tube then?   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

"Tom Miller" <tmiller11147@verizon.net>: Oct 21 02:43AM -0400 "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message news:1bKdnbx8Y66qsbrLnZ2dnUU7-WednZ2d@supernews.com...   > Cheers   > Phil Hobbs   > --   To get as much light as possible from a hand held tool. And Neon tubes are cheap. Remember, you had to hold the strobe close to the harmonic balancer while turning the distributor housing to set the timing. It got much easier when the consumer grade xenon units came out. Even then, they cost $100+ in the 60-70's. The neon units were $30-40.

captainvideo462009@gmail.com: Oct 20 10:10AM -0700 > I need to control the speed of a 1/3HP 120V AC motor. This motor/speed control would go onto a wood lathe and replace the pulley system which is now in place. Does anyone know of a solid state speed controller that I could perhaps build to to this? Thanks, Lenny   I think that this motor came out of a sump pump of the type that stands on the top of a sort of 3 foot pedestal. The pedestal would then go down into a hole such as the basement floor. Float switches would turn it on to keep the cellar from filling up with water.   This motor has no brushes and I'm fairly certain that it has a start winding because you can hear the centrifugal switch engage and disengage during start up and slow down. I do not have the exact speed information at hand however I do know that this motor runs at around 3000RPM. There is also very large capacitor on it as well.   So from what I'm reading here is there no real practical way to control the speed of this type of motor other than (as Mr. Cook mentioned) using a stepped pulley arrangement? Lenny

Cursitor Doom <curd@notformail.com>: Oct 20 06:05PM On Tue, 20 Oct 2015 08:40:49 +0100, N_Cook wrote:     > Pulley system increases torque at low speed of cutting Electronic > gubbins can only decrease torque at low speed   You would hardly notice any difference with a well-designed, modern controller. I bought one for a 415V 3ph industrial lathe I bought, which enables me to run it from 240V 1ph. The low speed torque is astounding - and the soft-start setting removes the lethality of hitting the start button when you've left the key in the chuck! Well worth the money - and you can still use gearing and pulleys with it for total versatility.

Tim R <timothy42b@aol.com>: Oct 20 11:52AM -0700 > On Monday, October 19, 2015 at 7:07:47 PM UTC-4, captainvi...@gmail.com wrote:     > I think that this motor came out of a sump pump of the type that stands on the top of a sort of 3 foot pedestal. The pedestal would then go down into a hole such as the basement floor. Float switches would turn it on to keep the cellar from filling up with water.   Is a sump pump motor intended for continuous operation? Or is it a duty cycle type motor? Wondering whether it will stand up to lathe operation.

Phil Allison <pallison49@gmail.com>: Oct 20 06:33PM -0700 Cursitor Doom wrote:   > You would hardly notice any difference with a well-designed, modern > controller. I bought one for a 415V 3ph industrial lathe I bought, which > enables me to run it from 240V 1ph. The low speed torque is astounding -     ** Torque from an electric motor depends mainly on current flow in the windings, so if a controller can supply the rated full load current at low rpms there is no loss of torque.   Controllers for induction motors ( aka Variable Frequency Drives) reduce the AC frequency and voltage fed to the motor to reduce rpms. Current flow is monitored so the windings do not overheat when the motor is heavily loaded or stalled.   But if increased torque is what is needed at low speeds, stick with the pulley system.     ... Phil

Jon Elson <jmelson@wustl.edu>: Oct 20 02:29PM -0500 Ian Field wrote:     > The Dell website wasn't much help, and it looks too old to find the > manual.   > Thanks for any help. Yes, you hold the menu button down for 10 seconds. When the padlock goes from locked to open, release the button.   I had one that got soda spilled into the little PC board with the button switches, and it ended up in the locked state once the board was cleaned. So, I had to unlock it.   Jon

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 20 09:14PM +0100 "Jon Elson" <jmelson@wustl.edu> wrote in message news:QrSdnQn8LIVJCLvLnZ2dnUU7-XWdnZ2d@giganews.com...   > I had one that got soda spilled into the little PC board with the button > switches, and it ended up in the locked state once the board was cleaned. > So, I had to unlock it.   Someone left the monitor and a bashed up Dell computer on the end of their drive with a note; "please take - free" - I just knew the monitor would come in handy.   The one I'd been using was scrounged on a free recycling group, they told me it was faulty and the buttons were dodgy, like something had been spilled down the front.   After cleaning the button PCB, I reflowed all the solder joints in the hope the heat would desiccate any lingering residues. It seemed OK for a while, but soon became apparent that the buttons had a life of their own in humid weather.   It got to be such a PITA that the Dell got put into service.

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.