Nothing In Particular

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Mike H
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#10831 Re: Nothing In Particular

Post by Mike H »

I'm messing with a little microprocessor board I've been putting together, and tried powering it up for the first time today. It promptly blew the 0.5 A on-board fuse. :shock: Can't find any obvious shorts. Tried "forcing" it with a croc lead bridging across the blown fuse. Fortunately I'm using a bench power supply possessing both an Ammeter AND current limiting, which, very usefully, works down to tens of milliamps, or less. (! :shock: )

The chip's booted up so must be working, ditto the 78L05 regulator etc. Correct Voltages. Neither are getting hot. There's a ULN2003 driver for output, not hot either. Yet it's pulling nearly 1 Amp. I decided to let it have more current and see if anything starts smoking.

Yep! An electrolytic, on the 12V supply input. Wrong polarity!

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"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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jack
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#10832 Re: Nothing In Particular

Post by jack »

Almost there!
Electrics all done. Carpet laid (hard wearing carpet tiles). IKEA shelving and tables being moved in. Walls all painted, windows stained, old rotten door frames removed and new ones made. Still have to make new cellar "stable style" ledged and braced door next week but not needed today - it's 7' x 4' x 1" so a fair bit of timber.

Lighting now all LED - warm white in office areas, cool white in workshop bits.

Got a mate who is a c&g electrician examinar coming in to check my wiring.

Office is warm and dry.
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Vivitur ingenio, caetera mortis erunt
Ant
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#10833 Re: Nothing In Particular

Post by Ant »

Had an odd couple of problems on tuesday with the system. Suddenly a load of hum, loads of odd buzzing regardless of input selected, and a seemingly knackered dynavector dv20a2.

I was most purterbed. I'd pulled the preamp out to test a build I'd just finished, and after this tested fine put the usual one back in. Thought id listen to some stuff on the lenco rather than the jvc and hit all the issues. Including a dead channel on the dv.

Thought it was the little switch box for the decks so I took that out first. No change. Could it be the arm cable? Pulled that out and stuck a meter on it, not that. Touching the cart body or even the stylus gave a nasty loud hum so I pulled the arm wand out (it's supposed to come out BTW) and checked continuity from the internal sprung pins to the plugs, and the earth. All fine. Checked the arm wand wiring and that was fine too. Took the cart off and put the sl15 in instead and we were back to 2 channels........ So I was now even more perturbed.

I still had a load of hum on all inputs to go with this, so I pulled the lot apart and redid all the cables, swapping the various bits of old shite out for some I made from bandridge mic cable. These are all shielded cables instead of whatever was in before. I really need a new cable loom...

Upshot was much reduced hum, but it was still there.
Come to use it this morning and it's silent again. I also checked the cart for coil continuity and that is fine with the coils measured dcr less than 1r different. Which is nice. Stuck it in a headshell and put it in the jvc and it works fine.........

So what was going on on Tuesday, I have no idea tbh.
A ghost in the machine.... And a lot of pulled out hair.
Also starring Rex Hamilton as Abraham Lincoln

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IslandPink
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#10834 Re: Nothing In Particular

Post by IslandPink »

Poltergeist !
"Once you find out ... the Circumstances ; then you can go out"
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Mike H
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#10835 Re: Nothing In Particular

Post by Mike H »

Very VERY dirty mains?

@ Nick: seriously impressive. :thumbleft:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Max N
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#10836 Re: Nothing In Particular

Post by Max N »

jack wrote: Thu Nov 28, 2019 9:11 am Almost there!
Electrics all done. Carpet laid (hard wearing carpet tiles). IKEA shelving and tables being moved in. Walls all painted, windows stained, old rotten door frames removed and new ones made. Still have to make new cellar "stable style" ledged and braced door next week but not needed today - it's 7' x 4' x 1" so a fair bit of timber.

Lighting now all LED - warm white in office areas, cool white in workshop bits.

Got a mate who is a c&g electrician examinar coming in to check my wiring.

Office is warm and dry
Well done Nick, very inspirational. Thanks for posting the progress reports.
I’ll be making a start this weekend on trying to rescue my shed before it falls down.
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Dave the bass
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#10837 Re: Nothing In Particular

Post by Dave the bass »

Nearly ran out of temperature here today, only 200 mC's left. Phew, that was close.

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"The fat bourgeois and his doppelganger"
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IslandPink
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#10838 Re: Nothing In Particular

Post by IslandPink »

"Luxury !"
You see this cloud-sea filling the vale of Clwyd yesterday afternoon ? - it all froze on my car :confused3:
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"Once you find out ... the Circumstances ; then you can go out"
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Dave the bass
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#10839 Re: Nothing In Particular

Post by Dave the bass »

Thats Hobbit territory innits?! Looks like it.
"The fat bourgeois and his doppelganger"
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jack
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#10840 Re: Nothing In Particular

Post by jack »

Getting closer...
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Dave the bass
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#10841 Re: Nothing In Particular

Post by Dave the bass »

Hobbits house!
"The fat bourgeois and his doppelganger"
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jack
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#10842 Re: Nothing In Particular

Post by jack »

Dave the bass wrote: Tue Dec 03, 2019 6:28 pm Hobbits house!
I'm not the one with hairy feet and a dodgy barnet, Mr. B :)

I can just get an 8x4 sheet of wood into the cellar, where I can render it into whatever's needed. Just one million times more convenient than having to wait for a dry day and then assemble everything outside in the garden.

I may or may not be onto something here, but I do believe indoors is the way to go. Yay!
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Mike H
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#10843 Re: Nothing In Particular

Post by Mike H »

Very cosy looking! A scene right out of Wind In The Willows
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Ant
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#10844 Re: Nothing In Particular

Post by Ant »

Oh dear... The 3009 needs a rewire.....
Thought I could just get away with doing a phono socket conversion, but the blue wire has a break in it somewhere. Piggin ell. At least it's a fairly easy job with one of these
Also starring Rex Hamilton as Abraham Lincoln

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IslandPink
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#10845 Re: Nothing In Particular

Post by IslandPink »

Bad luck .

Meanwhile, this is the type of tailored advertising I'm seeing now when I go on MSN news :
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"Once you find out ... the Circumstances ; then you can go out"
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