Cydrome Leader <presence@MUNGEpanix.com>: Jun 29 02:53AM
> *significantly* corrects the power factor. That does not change the
> current on the rest of the circuit to the motor, which has not been
> corrected.
If installed correctly it can help. You have to install it by the load.
Same concept as switchable power factgor correction banks installed at a
factory. It has to be near the load to reduce the distace you're pulling
empty current, lowering line voltage and regulation and wasting a bit of
power.
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Jeff Urban <jurb6006@gmail.com>: Jun 28 10:19PM -0700
Alright fuck it. There is one way.
You "tap" the power for milliseconds but at a very high peak current which is maybe the same wattage but you have done it so fast the meter misses some of it.
That is the ONLY way to really beat it and I am not sure it works on non-mechanical meters.
You take your 300 amp pulse to feed your shit, but not every cycle. Maybe every tenth cycle. You have heard of capacitors. You cannot use 6Hz 300 amp pulses very well so you have to go to DC and let it just charge at that cycle. The more you use the more you save. However you have to generate your own sine wave. It depends on you doing that efficiently. The only way I see is with some serious class D amps, and even those are not going to be small ass Icepowers.
And then for all the money you spend doing that you save 10% tops. So if your bill is $200 a month you save twenty bucks. /so buy all this shit for a few hundred if you're lucky, I think you are lucky to get it all for a grand, and then your time.
These are not on Amazon. Building your own, fine. But if you do that, to be able to design and build it twenty bucks an hour is the bare minimum.
So you want to put over a grand into saving twenty bucks a month. and then the gizmo might break and there is only one person who can fix it.
I am pretty sure I mentioned my Uncle and cousin experimenting with this. But then we have this other dude. All he did was lay a wire across his property and picked up the elecromagnetism from the high tension wires.
Now this of course became a transformer of sorts. But he got something out of it. In fact the more current he puled the more he helped the efficiency of the power company lines.
They busted him. Any time you gain any utility not paying the rate is a felony. It doesn't matter if you are helping them, it is the gain. The gain is what will cost you a few years and your gun and voting rights. By any method.
Now get this, if they can bust you for picking up a magnetic field they put up on your property then they can bust you for a crystal radio. Powered by radio waves, you got them for free, you going to the joint. Look it up - theft of utilities.
Like those things that give you even years of electricity (for an average house, not a foundry) for a million bucks. It simply is not worth it.
I can rewire a meter box so it only reads half what you use. It would take years for them to find out. I could make it read nothing, but that is stupid, they know better.
And that is reflected in watt-hour meter design. They thought of every possible way to cheat and addressed it. What would you do ?
There are a few things they did not think of but I am not going into that.
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"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 29 06:29AM -0700
Let me put it this way: It depends on the Utility. Here in PECO territory, they are commonly installed for about any commercial building (including residential buildings) over about 100,000 square feet that purchases "primary" power, and going back a far way in time.
Peter Wieck
Melrose Park, PA
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John Crane <john@localhost.net>: Jun 28 12:07PM -0500
On 06/28/2020 05:15 AM, Phil Allison wrote:
> Googling tells me this is a known hazard not shared with through hole parts - has to do with the use of silver plating on top surface of the resistor being subject to sulphiding and similar air borne contaminants.
> Any insights?
> .... Phil
I spent some time during my career as an electronics tech in the
petrochem industry. Lots of corrosive substances and vapors that will
kill electronics. It was common practice that after a board was
assembled and tested, it was bathed in a clear epoxy coat to completely
seal it.
-John
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jjhudak4@gmail.com: Jun 28 12:53PM -0700
On Sunday, June 28, 2020 at 1:07:15 PM UTC-4, John Crane wrote:
> assembled and tested, it was bathed in a clear epoxy coat to completely
> seal it.
> -John
It's called a conformal coating and they are a number of different types depending on the environmental conditions one is trying to safeguard the electronics with.
I think Phil's question is more along the lines of the failure modes of the SMD resistors or interaction with the board material.
I have not heard of the failure mode Phil has described. IIRC, the sulphiding will form an insulation layer, so poking with needle probes is necessary to get good readings. I have not read anything about how the sulphiding changes the resistor characteristics. Sorry.
The only thing I am aware of, which is remotely related to this is the tin 'whisker' phenomenon which shorts out components. Caused by when tin (especially electroplated tin) is used as a final finish.
Could hot air reflowing the areas where the resistors are located help? or have the resistors themselves really undergone the change?
Sorry I could not be of more help
J
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Trevor Wilson <trevor@rageaudio.com.au>: Jun 29 06:19AM +1000
On 28/06/2020 8:15 pm, Phil Allison wrote:
> Eventually I found 3 open resistors, all with values like 1Mohm.
> Googling tells me this is a known hazard not shared with through hole parts - has to do with the use of silver plating on top surface of the resistor being subject to sulphiding and similar air borne contaminants.
> Any insights?
**If I have a weird fault, I always suspect high value (>100k) or low
value (<100 Ohms) resistors. Both sometimes fail for different reasons.
That said, mostly I find such faults confined to cracked carbon resistors.
--
Trevor Wilson
www.rageaudio.com.au
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Trevor Wilson <trevor@rageaudio.com.au>: Jun 29 06:23AM +1000
On 28/06/2020 8:15 pm, Phil Allison wrote:
> Eventually I found 3 open resistors, all with values like 1Mohm.
> Googling tells me this is a known hazard not shared with through hole parts - has to do with the use of silver plating on top surface of the resistor being subject to sulphiding and similar air borne contaminants.
> Any insights?
**Also: Get yourself a pair of these:
https://www.wagneronline.com.au/4mm-plug-on-test-probe-hck-silicone/test-leads-hck-silicone/test-measure/tools-test/6762/fl/
Pierces insulation (and fingers!) easily.
--
Trevor Wilson
www.rageaudio.com.au
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jjhudak4@gmail.com: Jun 28 01:40PM -0700
On Sunday, June 28, 2020 at 6:15:19 AM UTC-4, Phil Allison wrote:
> Googling tells me this is a known hazard not shared with through hole parts - has to do with the use of silver plating on top surface of the resistor being subject to sulphiding and similar air borne contaminants.
> Any insights?
> .... Phil
The pointer to the tool is interesting to me. It beats keeping an old style pencil eraser around, which tends to dry out over time...speaking of that....
What is the material in this pen? fiberglass? and does it dry up or change hardness in any way?
Thanks
J
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Fox's Mercantile <jdangus@att.net>: Jun 28 04:07PM -0500
> The pointer to the tool is interesting to me. It beats keeping an old style pencil eraser around, which tends to dry out over time...speaking of that....
> What is the material in this pen? fiberglass? and does it dry up or change hardness in any way?
I have a couple in my tool box.
The brush is stiff fiberglass, and you can adjust the length.
It works amazingly well.
And no, nothing changes with age.
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
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Terry Schwartz <tschw10117@aol.com>: Jun 28 04:08PM -0700
On Sunday, June 28, 2020 at 5:15:19 AM UTC-5, Phil Allison wrote:
> Googling tells me this is a known hazard not shared with through hole parts - has to do with the use of silver plating on top surface of the resistor being subject to sulphiding and similar air borne contaminants.
> Any insights?
> .... Phil
Not unusual for high value resistors to fail open. This was also true for leaded resistors. The same environmental conditions that cause the surface corrosion contribute to the resistor failures.
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Phil Allison <pallison49@gmail.com>: Jun 28 07:04PM -0700
Terry Schwartz wrote:
====================
> Not unusual for high value resistors to fail open.
** Well they don't fail short very often - but high rates of such in new looking equipment is very unusual.
> This was also true for leaded resistors.
** Only those with lots of DC across them, not the case here.
> The same environmental conditions that cause the surface corrosion
> contribute to the resistor failures.
** Yeah - I did figure that.
But chip resistors are unusually vulnerable cos of exposed silver.
..... Phil
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Trevor Wilson <trevor@rageaudio.com.au>: Jun 29 12:22PM +1000
On 29/06/2020 12:04 pm, Phil Allison wrote:
> ====================
>> Not unusual for high value resistors to fail open.
> ** Well they don't fail short very often - but high rates of such in new looking equipment is very unusual.
**I've never seen them fail S/C. O/C, yes.
>> This was also true for leaded resistors.
> ** Only those with lots of DC across them, not the case here.
**Nope. Seen lots fail over the years. Even those in preamp sections,
when Voltages are well below 40 Volts.
>> contribute to the resistor failures.
> ** Yeah - I did figure that.
> But chip resistors are unusually vulnerable cos of exposed silver.
**Certainly are. I've seen a few fail.
--
Trevor Wilson
www.rageaudio.com.au
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Phil Allison <pallison49@gmail.com>: Jun 28 07:24PM -0700
Trevor Wilson wrote:
================
> **If I have a weird fault, I always suspect high value (>100k) or low
> value (<100 Ohms) resistors.
** That is why I went on a bad resistor hunt - after everything else proved OK.
> That said, mostly I find such faults confined to cracked carbon resistors.
** Small carbon film resistors regularly fail (open) due to high voltage "tracking" between turns on the spiral cut. Plate resistors in triode stages for one.
IME - metal film and cermet types ( ie chip resistors) are less prone to do the same.
.... Phil
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Trevor Wilson <trevor@rageaudio.com.au>: Jun 29 12:43PM +1000
On 29/06/2020 12:24 pm, Phil Allison wrote:
>> **If I have a weird fault, I always suspect high value (>100k) or low
>> value (<100 Ohms) resistors.
> ** That is why I went on a bad resistor hunt - after everything else proved OK.
**The most painful ones I've seen were popular in Sansui products a few
decades back. They were typically in the range of 100 ohms ~ 47k and
would go high. Frequently to around double the value printed on them.
Fault finding was very difficult, since Voltages were almost what they
were supposed to be. Almost, but not quite.
>> That said, mostly I find such faults confined to cracked carbon resistors.
> ** Small carbon film resistors regularly fail (open) due to high voltage "tracking" between turns on the spiral cut. Plate resistors in triode stages for one.
> IME - metal film and cermet types ( ie chip resistors) are less prone to do the same.
**I've seen plenty of >100k resistors go high, despite being subject o
Voltages of less than 40 Volts.
--
Trevor Wilson
www.rageaudio.com.au
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Phil Allison <pallison49@gmail.com>: Jun 28 08:25PM -0700
Trevor Wilson wrote:
===================
> >> Not unusual for high value resistors to fail open.
> > ** Well they don't fail short very often - but high rates of such in new looking equipment is very unusual.
> **I've never seen them fail S/C.
** ROTFL....
> >> This was also true for leaded resistors.
> > ** Only those with lots of DC across them, not the case here.
> **Nope. Seen lots fail over the years.
** Yawnnnn......
TW claims all kinds of impossible things.
> > But chip resistors are unusually vulnerable cos of exposed silver.
> **Certainly are. I've seen a few fail.
** The amp in question is a "DV Mark" combo with 3 x PCBs covered in SMD.
Every chip resistor ( 100+ of them ) is corroded after storage in its original packaging for 6 years or so.
It uses just 2 obsolete Sanken SAP 5-pin darlingtons, has no VI limiting or rail fuses but has an extension speaker jack just waiting to be shorted. Peak available output current is +/- 30 amps double the max Ic of the transistor.
SMPS with the markings ground off the control chip.
Will drive 200W @ 4ohms but has totally inadequate cooling for this condition and no thermal shut down.
The fitted speaker is 16 ohms with a *tin* neo magnet.
No schem is available.
Total PITA.
..... Phil
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