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meanwhile out in the garage ...
- Thread starter kopcicle
- Start date
The leg and ankle are feeling better, still had a heck of a time climbing the latter. Put new LED lights in the shop, still need to replace 6 more florescent bulbs. That UFO looking thing hanging from the ceiling is a heater from a chicken house, 40,000 BTU runs off propane, a guy I know gave me 2 of them for free, he recently got out of chicken business.
That's nice, I just bought my first table saw and compound miter saw. I seen a refurbished Grizzly table saw on Craigslist, $1200 was more than I could get away with when it comes to the wife.
So once again I prevail on the varied talents of the subversive membership of this storied niche of the interwebz.
hydroxylammonium nitrate, Ni 3 OHNO 3
I'm a little over my pay grade here and need an Elmer.
I'll fidget a bit and reason what I can of it .
I have been the exception to the thought that you can't teach an old dog new tricks. This trick will just take longer.
PM if you get the drift immediately and at least think you know me that well.
If not , consider it a puzzle and continue here.
We live in interesting times
hydroxylammonium nitrate, Ni 3 OHNO 3
I'm a little over my pay grade here and need an Elmer.
I'll fidget a bit and reason what I can of it .
I have been the exception to the thought that you can't teach an old dog new tricks. This trick will just take longer.
PM if you get the drift immediately and at least think you know me that well.
If not , consider it a puzzle and continue here.
We live in interesting times
Although this is primarily directed at the confusing nonsense that is an Astron power supply I have to take a moment to waken @Handy Andy and let him know I get it and details are on the way.
First , many thanks to @nomadradio for the scribbles.
The first failure noted in this creature was that the screw for the positive terminal of the main 32,000 MFD 25V at C5 was too long, installed w/o lock washer, and arced on power up.
The next observed failure was although the no load voltage was near 12V a minuscule load would erase it. I had purchased the rectifier diodes (1N1184A) and the series pass transistors (2N3771) anticipating that everything had commited seppuku.
There was just one issue with this.
...so I get near 30VDC at the top of C5 , 32,000 mfd 25V
and then it disappears in the 2n3771's. This would not be that big a problem since I have the replacement transistors. There's just one annoying problem, the leads on the replacement transistors are significantly smaller in diameter. I seem to remember this happening once (or more) before but I don't remember what I used for a fix. I'll probably put a dab of solder on the end of the legs and risk creating a curious point of failure.
I can't stick with a project like I used to so this will come in installments.
First , many thanks to @nomadradio for the scribbles.
The first failure noted in this creature was that the screw for the positive terminal of the main 32,000 MFD 25V at C5 was too long, installed w/o lock washer, and arced on power up.
The next observed failure was although the no load voltage was near 12V a minuscule load would erase it. I had purchased the rectifier diodes (1N1184A) and the series pass transistors (2N3771) anticipating that everything had commited seppuku.
There was just one issue with this.
...so I get near 30VDC at the top of C5 , 32,000 mfd 25V
and then it disappears in the 2n3771's. This would not be that big a problem since I have the replacement transistors. There's just one annoying problem, the leads on the replacement transistors are significantly smaller in diameter. I seem to remember this happening once (or more) before but I don't remember what I used for a fix. I'll probably put a dab of solder on the end of the legs and risk creating a curious point of failure.
I can't stick with a project like I used to so this will come in installments.
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What I used to tell the hired help back in the dark ages was to unsolder and test every semiconductor component. Every transistor, diode and zener. A chip like a 723 can't be tested this way, but once you find EVERY two or three-terminal device that's bad, that chip either works or won't. If it saves effort, unhooking only two out of three terminals lets the tester do its job.
A surprisingly high percentage of repairs got done this way. Replace every part that flunks its test.
Back when there was a buck to be made that way. Many moons ago our standard advice to a customer with a broken power supply became "replace don't repair. Like I said, back in the dark ages.
But it can be done. Just gotta stay on the lookout for Murphy. Powering up a power supply that still has one bad part lingering in it can wipe out one or more brand-new parts you just installed. And that was the point of telling the help to check EVERY semiconductor component.
73
A surprisingly high percentage of repairs got done this way. Replace every part that flunks its test.
Back when there was a buck to be made that way. Many moons ago our standard advice to a customer with a broken power supply became "replace don't repair. Like I said, back in the dark ages.
But it can be done. Just gotta stay on the lookout for Murphy. Powering up a power supply that still has one bad part lingering in it can wipe out one or more brand-new parts you just installed. And that was the point of telling the help to check EVERY semiconductor component.
73
@kopcicle - funny how you mention smaller leads.
The Astron, Tripp-Lite or others from a decade or two ago, like you just showed use older computer Linear Power Supply transformers to do this job.
The +10Amp side was designed for 5V to 12V linear regulators while the other winding set was to power the LM723.
They kept the 723 design, only the expanded the 5V to use both sides of the CT wind for the 10A or greater (Iron size per model) to provide the 12V to 13.6 10~25A output the thing could rectify safely for.. Since it uses a "Full-wave" design, you could get the higher output and use the less windings side for the Amperage they rated them for in a typical 12V system.
Several power supplies I've seen in the past, popped the Trace to protect the Power Device.
Several others popped in the set of Winds back at the core - even show a current, but the wind is open if it doesn't show any continuity to complete the circuit.
When you say it disappears, does the winding of the Iron - thru the bridge to that connection of the Collector - show continuity?
Could be the Iron popped, or the Trace from it opened.
The Astron, Tripp-Lite or others from a decade or two ago, like you just showed use older computer Linear Power Supply transformers to do this job.
The +10Amp side was designed for 5V to 12V linear regulators while the other winding set was to power the LM723.
They kept the 723 design, only the expanded the 5V to use both sides of the CT wind for the 10A or greater (Iron size per model) to provide the 12V to 13.6 10~25A output the thing could rectify safely for.. Since it uses a "Full-wave" design, you could get the higher output and use the less windings side for the Amperage they rated them for in a typical 12V system.
Several power supplies I've seen in the past, popped the Trace to protect the Power Device.
Several others popped in the set of Winds back at the core - even show a current, but the wind is open if it doesn't show any continuity to complete the circuit.
When you say it disappears, does the winding of the Iron - thru the bridge to that connection of the Collector - show continuity?
Could be the Iron popped, or the Trace from it opened.
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