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amdx <nojunk@knology.net>: Aug 07 01:37PM -0500 > wiring relays in a vehicle alarm circuit, I was isolating flow with open diode end always facing the 12V supply wether diode was before a sensor or horn or after on the ground side.   > then I read that ground side diodes are wired with the diode open side facing the ground with the band facing the sensor or horn ...   > ?   Still don't have enough info. There are two possible uses that I see from the limited info. The diode could be used to protect the relay driver from the voltage spike generated when you remove current from the relay coil. In that case the diode is across the relay, reverse biased when the diode is energized. I can't think why, but you could be using diodes to steer current, so that, if this is on, that is not on, or some such thing. That you just need to figure out. A schematic of your circuit would provide you with an answer. Mikek   --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com

avagadro7@gmail.com: Aug 07 08:52PM -0700 Right in both suggestions.   The overall problem is the siren in the engine area grounded to fender does not so far accept a relay connection for 12v from battery using 12v from alarm brain for switching batt power...   But to my delight and amazement, 2 rear roof mounted relays transfer 12v batt power with the brain's 12v signal.   The brain 12v all wire onto the same block terminal.   Lookin for an answer in text or image before trial n E, I ran into poor English probably from Korean..."when switched ground" then the rule for mounting diodes on power from batt with open end toward power and on the ground side mounted opposite with open diode side toward the physical ground side.   If that is true then not only have I isolated field areas incorrectly but am missing basic theory on how ground functions

amdx <nojunk@knology.net>: Aug 08 06:34AM -0500 > Lookin for an answer in text or image before trial n E, I ran into poor English probably from Korean..."when switched ground" then the rule for mounting diodes on power from batt with open end toward power > and on the ground side mounted opposite with open diode side toward the physical ground side.   > If that is true then not only have I isolated field areas incorrectly but am missing basic theory on how ground functions   Can you make a drawing of the circuit.   Mikek

avagadro7@gmail.com: Aug 08 05:47AM -0700 oh sure but the question was is the statement abt diode position visavee 12V and ground valid ? as a rule ?   I see the problem in my wiring that is all relay direct power switching is done on the ground side of the load. Optimism !       http://www.caraudiohelp.com/images/relay_for_remote.gif   big deal.   if I wanted to isolate this relays ground from the other grounds on the local ground bolt, I would wire in a diode with   the stripe facing the relay   or the stripe facing away from the relay ?

"Arfa Daily" <arfa.daily@ntlworld.com>: Aug 08 12:00AM +0100 "Phil Allison" <pallison49@gmail.com> wrote in message news:0cfd1989-afa9-4e30-85d0-0053392043eb@googlegroups.com...   > Very sad to hear of George Cole's passing.   > .... Phil   Yeah, I was very sad too, but he did have a good innings lasting until he was 90. Dennis Waterman was still good friends with him as well. He's looking a bit rough now, though ...   I saw every episode of Minder that was ever made. They all had very clever 'play on words' titles, and the first two series were actually quite dark stories. They didn't think it was going to last beyond that, but the comedy element was deliberately ramped up in the third series by the interaction between Cole and Waterman, and it became an overnight success. I just loved the character Arthur Daley for the wicked sense of comic timing and the malapropism he employed. And of course, it was made by Euston Films, the absolute kings of drama made in London.   Back to the crown. The transformers in this 5000 model are truly massive torroidals, and I'm leaning towards suspecting shorted turns on the primary of the one on the bad channel. The inrush thermistors are the size of penny toffees - the biggest I've ever seen. From the sheet of flame that shot out of this one and the number of bench fuses that blew, the short must be right on top of the thermistor. The fact that you can only get to about 20 v of AC input before the variac is jumping off the bench, also makes me think shorted primary.   Unfortunately, it's not an easy task to get to the secondary side of the PSU, as it's one of those two-board constructions, where one power amp is stacked on top of the other, and all of the bridges and filter caps for both amps are, needless-to-say, on the bottom board where you can't get to anything.   Before going to all of the trouble to get the top board out to see if I can unplug the tranny secondaries, I'm waiting on the shop getting in touch with the owner to give him an estimate of what it might cost, depending on what I find. I'm not sure what the spares position for Crown stuff is like here in the UK, if it needed a tranny ...   Arfa

Phil Allison <pallison49@gmail.com>: Aug 07 08:21PM -0700 Arfa Daily wrote:     > I just loved > the character Arthur Daley for the wicked sense of comic timing and the > malapropism he employed.     ** Like: " The world is your lobster... "   > stacked on top of the other, and all of the bridges and filter caps for both > amps are, needless-to-say, on the bottom board where you can't get to > anything.   * You could snip the leads for the main secondary ( leaving the CT) and join them again if the tranny proves OK.     > the owner to give him an estimate of what it might cost, depending on what I > find. I'm not sure what the spares position for Crown stuff is like here in > the UK, if it needed a tranny ...   ** Out of curiosity, I stripped down the tranny from that XLS602. Internal shorts in large toroidals are very rare, especially with no other fault.   The whole thing was rough as guts, with a wound core made from dozens of off- cuts of steel strip tacked welded together and bits of cloth tape covering the edges. Normal toroidal cores are precison made and have moulded plastic covers covering all sharp edges, where the primary is wound.   The twin 120/240 primary was bi-filar wound placing 120VAC between every adjacent turn, a dodgy practice at best and fatal if the enamel coating ever gets damaged.     ... Phil

"Arfa Daily" <arfa.daily@ntlworld.com>: Aug 08 11:28AM +0100 "Phil Allison" <pallison49@gmail.com> wrote in message news:a33880be-d30a-4c3b-8d2d-3ec8cb434625@googlegroups.com... >> anything.   > * You could snip the leads for the main secondary ( leaving the CT) and > join them again if the tranny proves OK.     Hadn't thought of that. I've got schematics for the thing, so shouldn't be too hard to identify which wires are what. The primary is on a plug that's easy to get to, and all is well with that pulled off, so nothing else on the input board is the problem.     > covering the edges. Normal toroidal cores are precison made and have > moulded plastic covers covering all sharp edges, where the primary is > wound.   That's interesting. If this turns out to be the tranny, and the owner goes ahead - assuming we can get one, of course - I will try to find the time to have a look. Over the last couple of years, I've had probably three or four large toroidals with shorted primaries, so maybe there's some Chinese factory churning out cheapies like the one you saw, virtually made from scrap ...     > The twin 120/240 primary was bi-filar wound placing 120VAC between every > adjacent turn, a dodgy practice at best and fatal if the enamel coating > ever gets damaged.   Yes, not a good practice for sure. I suppose though that it's hard to find a way to wind a twin primary on a toroidal core where you're trying to keep the profile low, and a similar level of core coupling from both windings. Much easier when you have a traditional E-I core and can have two primaries stacked on top of one another, I guess   Arfa

Phil Allison <pallison49@gmail.com>: Aug 08 05:16AM -0700 Arfa Daily wrote: > large toroidals with shorted primaries, so maybe there's some Chinese > factory churning out cheapies like the one you saw, virtually made from > scrap ...   ** The transformer maker used in the XLS series is:   " NRE Electrical Manufacturing Co Ltd ".   www.fsnre.com     ( I posted the same details here on December 10,2014 )   BTW:   Is it possible the company is being run by a Mr Dai Lee ??       ... Phil

Jeff Liebermann <jeffl@cruzio.com>: Aug 07 07:40PM -0700 HP Envy m6 laptop (with AMD A10 processor), which arrive with a bad case of overheating. Here's what the radiator grill looked like after I tore apart the laptop to clean out the filth: http://802.11junk.com/jeffl/pics/repair/HP%20Envy%20m6%20clogged%20fan/slides/clogged_fan.html That's about 50% clogged. It took about 45 mins to overheat and shut down in self defense. The owner didn't really notice that there was an overheating problem, but did notice that the machine seemed to run slower when hot. I certainly noticed when I tried to do an image backup for 100 GBytes of kids games and found that it overheated and shut down in the middle of the backup (3 times). Note that the picture was AFTER I had hit the fan with my 60 psi air hose from every conceivable angle to try and clear out the crud. No luck.   Here's what I had to do to the laptop to clean it out: http://802.11junk.com/jeffl/pics/repair/HP%20Envy%20m6%20clogged%20fan/slides/HP%20Envy%20m6%20A10%20CPU.html General lack of easy maintenance features is one reason I don't like HP products.   The real problem is the mechanical design. The grill on the heat pipe is made for maximum cooling, not minimum filth accumulation. I did an experiment once with some dog hair clippings (don't ask) to see what really happens when a laptop sucks in short hair cuttings. The long hairs are blocked by the small holes in the grill work. The dust goes right through and out the exhaust port. However, tiny hair fragments between about 4 to 6 mm go through the holes, through fan, and get jammed up against the radiator grill. Initially, most of these short hairs went right through, but as the few that got stuck increased, more and more began to get caught until air flow was constricted to about 30% of maximum. It happened quite fast and was impressive to watch through a clear plastic fake cover. (I should do a YouTube video). After the test, I found that I could easily blow out most of the hair because there was no grease or goo to hold the fur ball in place. The laptop in the photo was possibly used near something that produced greasy fumes (kitchen or oil burning furnace). It took about 3 years to look like the photo. I forgot to take a photo of the fan. It was fairly clean except for greasy dirt stuck to the blades. I could hear the fan struggling, but it was against the back pressure, not friction from the filth. Again, the picture was AFTER I had blown out the laptop with 60 PSI compressed air from my blow gun in both directions.     -- 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

avagadro7@gmail.com: Aug 07 09:08PM -0700 "They all do that"

DaveC <not@home.cow>: Aug 07 11:02PM -0700 On 7 Aug 2015, avagadro7@gmail.com wrote   > "They all do that"   Actually, they all *do* (in time)…

Cydrome Leader <presence@MUNGEpanix.com>: Aug 08 06:29AM > The real problem is the mechanical design. The grill on the heat pipe > is made for maximum cooling, not minimum filth accumulation. I did an > experiment once with some dog hair clippings (don't ask) to see what   ha, nice test.   I recall an old stale cigar being used to test airflow though audio amps at one shop.

N_Cook <diverse@tcp.co.uk>: Aug 08 08:13AM +0100 On 08/08/2015 03:40, Jeff Liebermann wrote: > not friction from the filth. Again, the picture was AFTER I had blown > out the laptop with 60 PSI compressed air from my blow gun in both > directions.   Related to that, notebooks and laptops, ie often used on laps. I'm surprised how few outlet grills have a bulge around them to stop loose clothing blocking the air outlet. Cut bit/s of blue hotmelt glue stick and glue the disc/crescent to the periphery simply sorts that one

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Aug 08 07:43AM +1000 On 7/08/2015 11:21 PM, Phil Allison wrote:   > https://www.youtube.com/watch?v=RhOhTb4OnRg   > See 18 minutes into this U-tube.   > Looks like every episode of Minder made is on U-tube.   **LOL! Thanks for that.   Arfur: "...bereavement, very dodgy thing to handle. (without a pause and kicks one tyre) New tyres?"     Brilliant stuff.     -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

John-Del <ohger1s@aol.com>: Aug 07 07:44PM -0700 On Thursday, August 6, 2015 at 10:42:40 AM UTC-4, Arfa Daily wrote:   > RIP, old mate ...   > http://www.bbc.co.uk/news/entertainment-arts-33803144   > Arfa :-(     No one has mentioned his role as young Ebenezer in Scrooge 1951!

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