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Author Topic: 4.5kva output  (Read 3320 times)

BruceM

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Re: 4.5kva output
« Reply #15 on: February 06, 2019, 04:17:02 PM »
Shitty switching supplies are the cause of much home power EMI.  There is no regulation of appliance emissions, and often the home wiring is a strong broadband radio transmitter for something as idiotic as a washing machine that is "off", or a cheap china battery charger left plugged in.  Or a new fancy digitalized heat pump system, etc., etc.  I think it's a foolish way to spend down your health.  It was idiotic to wrap ourselves in the unshielded power cables of our homes, but that is what we've done.

FYI-  Hackaday did a tear down on three LED bulbs.

https://hackaday.com/2019/02/05/what-happened-to-the-100000-hour-led-bulbs/

The GE Basic and Classic bulbs have no switching supply, just bridge rectify the mains to an electrolytic capacitor, with a linear current regulator to the leds in series.  The results of this design-  fairly low EMI, just the emissions of the unsnubbed bridge diodes at 50ma of current.  It could be a Lister flicker problem if your voltage dips too much on the compression stroke, but it's likely OK for SOM's or those with AVRs.

The Cree bulb they tore down has a crappy little switching power supply, so lots of EMI but likely no Lister Flicker. 

An AM radio with loud static between stations is an effective ''poor man's near field sniffer'' for checking home power EMI.  The AM band is in the range of typical switching EMI harmonics.  If your home wiring is affecting much of the AM band, over 2 feet from the wires, you've got a serious problem that should be addressed.  Common mode chokes or other suitable commercial passive filters are one cheap and simple fix, that go between the offending equipment and the outlet. Those without a digital meter can quickly isolate problems by listening to the AM radio at the main power panel as you switch breakers off.  With a digital or smart meter, you can't do that as easily since the meter itself often has a laughably bad switching supply without any filtration at all; the power company doesn't have to meet any emissions specs, so dollar was saved.

Most computer switching supplies will at least meet conducted emissions standards, though that isn't saying much.  Appliances aren't regulated for conducted emissions, so anything goes.


 










dieselspanner

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Re: 4.5kva output
« Reply #16 on: February 06, 2019, 09:52:21 PM »
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

BruceM

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Re: 4.5kva output
« Reply #17 on: February 06, 2019, 10:06:16 PM »
I saw the Radio Shack 12-467 on the AU ebay, that's my favorite.
Sony makes a new cheap portable that's also pretty good as an EMI near field sniffer.  I can't find mine or I'd give you a model no.

There's still plenty of new cheap, non-digital AM/FM radios being made.  If you can hear loud static between stations, it should work fine.

« Last Edit: February 06, 2019, 10:08:07 PM by BruceM »

listeroil

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Re: 4.5kva output
« Reply #18 on: April 11, 2020, 01:37:41 PM »
I said I had this brochure a year ago.  I have scanned it and cleaned it up a bit.  It shows how the engines were built to BS 649/1958 and alternators to BS 2613/1957 Both of them capable of being run continuously and 10% overloaded for up to an hour in 12 hours. So theoretically the Lister 4.5Kw alternator is capable of producing 4.94 Kw absolute max for an hour.