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Bench Lights
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jurb...@gmail.com
Apr 1, 2019, 9:56:48 PM4/1/19
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Well, they are mostly CCFL. Of course they have Royers in them and they generate EMI. I got an HP339a and to find its measurement flkoor of 0.0016% I had to connect the output to the input with wires as straight as possible. Using anything else it picked up too much noise, even with the filters on.
Then I am working on a scope and the trace is fat, I pull the arm light away and it flattens out. I turn off all the lights and I got the flatline I should.
So now I got a halogen in the arm lamp, which helps. I also still have the ability to shut of all the lights and have everything else still work. Even with the rest of the lights farther away it still has noticeable EMI.
The halogen is alright but it gets hot. that is inefficiency and not much though because it is like 50 watts. But it makes the shield on my arm lamp hot and that is not only not nice now, any heat generation in the summer is no good here. We don't even use the oven. This is a BIG house and when that A/C comes on it is over a buck an hour to run the compressor.
I wonder now about LED lighting. I know it runs on a couple of volts, and if they are downconverting it it is surely switched mode. Or is it ? They would not just use a resistor, trying to be efficient.
If LED lighting does not emit much EMI I will consider changing to it. This place is bad enough with the bad wiring, yes I know I have to take care of that but still, that EMI is not what is coming form the light bulbs. But what is is up close and personal.
What y'all use for that ?
Then I am working on a scope and the trace is fat, I pull the arm light away and it flattens out. I turn off all the lights and I got the flatline I should.
So now I got a halogen in the arm lamp, which helps. I also still have the ability to shut of all the lights and have everything else still work. Even with the rest of the lights farther away it still has noticeable EMI.
The halogen is alright but it gets hot. that is inefficiency and not much though because it is like 50 watts. But it makes the shield on my arm lamp hot and that is not only not nice now, any heat generation in the summer is no good here. We don't even use the oven. This is a BIG house and when that A/C comes on it is over a buck an hour to run the compressor.
I wonder now about LED lighting. I know it runs on a couple of volts, and if they are downconverting it it is surely switched mode. Or is it ? They would not just use a resistor, trying to be efficient.
If LED lighting does not emit much EMI I will consider changing to it. This place is bad enough with the bad wiring, yes I know I have to take care of that but still, that EMI is not what is coming form the light bulbs. But what is is up close and personal.
What y'all use for that ?
bitrex
Apr 2, 2019, 1:12:35 AM4/2/19
to
each side. There are several different models. Works great and I don't
notice any EMI issues. Some people bitchin' about reliability problems
but hasn't happened to me yet.
<https://www.amazon.com/Brightech-Sparq-Lighting-Bedrooms-Minimalist/dp/B07DV2HWKJ/ref=sr_1_13?keywords=britech+floor+lamp&qid=1554181744&s=gateway&sr=8-13>
I have a halogen gooseneck too but hardly need it
Jeff Liebermann
Apr 2, 2019, 2:36:33 AM4/2/19
to
On Mon, 1 Apr 2019 18:56:45 -0700 (PDT), jurb...@gmail.com wrote:
>If LED lighting does not emit much EMI I will consider changing
>to it. This place is bad enough with the bad wiring, yes I know
>I have to take care of that but still, that EMI is not what is
>coming form the light bulbs. But what is is up close and personal.
Dirty Electricity from LEDs
>If LED lighting does not emit much EMI I will consider changing
>to it. This place is bad enough with the bad wiring, yes I know
>I have to take care of that but still, that EMI is not what is
>coming form the light bulbs. But what is is up close and personal.
<https://healthybuildingscience.com/2017/06/05/dirty-electricity-leds/>
The worst part is that I've found wide variations in EMI from
commodity LED light bulbs. In the same box of bulbs, some are very
noisy, while others are tolerably quiet. You may need to individually
test the bulbs to find the best.
>What y'all use for that ?
company for lighting a screen room. However, I was soon ordered to
remove them because they were a fire hazard. I though the "ambience"
was rather nice, but I have to admit that it wouldn't have taken much
to start a fire. I didn't try these, but I think Cyalume glow sticks
might have worked:
<https://www.google.com/search?tbm=isch&q=cyalume>
Yellow seems the brightest. You get about 12 hrs per stick at about
$1.25/ea. I think 4 would be sufficient to light up a test bench.
That's $5 per day for lighting, which is expensive but tolerable
compared to the cost of LED lights, ferrite bead filtering, and
possibly wire mesh shielding.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
J.B. Wood
Apr 2, 2019, 6:23:28 AM4/2/19
to
On 4/1/19 9:56 PM, jurb...@gmail.com wrote:
> Well, they are mostly CCFL. Of course they have Royers in them and they generate EMI. I got an HP339a and to find its measurement flkoor of 0.0016% I had to connect the output to the input with wires as straight as possible. Using anything else it picked up too much noise, even with the filters on.
>
> Then I am working on a scope and the trace is fat, I pull the arm light away and it flattens out. I turn off all the lights and I got the flatline I should.
>
> So now I got a halogen in the arm lamp, which helps. I also still have the ability to shut of all the lights and have everything else still work. Even with the rest of the lights farther away it still has noticeable EMI.
>
Hello, and I use a '70s era Tensor high-intensity lamp (also doubles as
>
> Then I am working on a scope and the trace is fat, I pull the arm light away and it flattens out. I turn off all the lights and I got the flatline I should.
>
> So now I got a halogen in the arm lamp, which helps. I also still have the ability to shut of all the lights and have everything else still work. Even with the rest of the lights farther away it still has noticeable EMI.
>
a piano lamp). It uses a 12-volt automotive bulb and has a high and low
brightness switch. Oh, yeah, and no noise/EMI issues and plenty of
light for close-in work. Sometimes older works better (except perhaps
with people). Sincerely,
--
J. B. Wood e-mail: arl_1...@hotmail.com
tabb...@gmail.com
Apr 2, 2019, 7:00:43 AM4/2/19
to
NT
Lucifer
Apr 5, 2019, 11:09:51 PM4/5/19
to
On Tuesday, 2 April 2019 02:56:48 UTC+1, jurb...@gmail.com wrote:
> I wonder now about LED lighting. I know it runs on a couple of volts,
> and if they are downconverting it it is surely switched mode. Or is
> it ? They would not just use a resistor, trying to be efficient.
They use capacitive droppers.
> I wonder now about LED lighting. I know it runs on a couple of volts,
> and if they are downconverting it it is surely switched mode. Or is
> it ? They would not just use a resistor, trying to be efficient.
mrob...@att.net
Apr 13, 2019, 3:16:52 PM4/13/19
to
jurb...@gmail.com wrote:
> I know it runs on a couple of volts, and if they are downconverting it
> it is surely switched mode. Or is it ?
The couple of LED lamps I have plugged into my Kill-a-Watt meter come up
> I know it runs on a couple of volts, and if they are downconverting it
> it is surely switched mode. Or is it ?
with power factors around either 0.6 (the cheapest ones) or 0.8 (a nicer
Philips "dimmable" one), if that tells you anything.
> What y'all use for that ?
fixtures over the bench, because they were cheap. :) I am not usually
trying to do tiny-signal stuff, though.
If you do want to make "low noise" LED lighting, here are some ideas...
1. Go to the big-box store and buy one of those LED "work lights" - the
ones shaped like the old 300 W / 500 W halogen flood lights. Remove
the existing power supply and drive it with a linear power supply at
the right voltage. (Hopefully the power supply isn't potted/
impossibly entangled with the LEDs.) Work up an adapter from the
"eye" / mounting holes on the back to one of your arm light brackets.
2. Roll-your-own with LEDs and some perf board, or ready-made boards
from somebody like http://bigclive.com/shop.htm . Clive made his
boards before you could even get ready-made LED lamps at retail.
They are designed for strings of R, G, and B LEDs, but you could
also just buy white LEDs and install them. If you end up needing
less light, just don't populate the whole board.
3. Go to the car parts store and buy some LED lamps that are designed
to replace regular 12 V lamps in vehicles. I think pretty much all
of these just use resistors in series with the 12 V. You also get
to figure out a socket, reflector, etc (or use one off of a car).
4. Get some of the LED modules that are designed to go in signs for
buildings, as a replacement for neon tubes. Sometimes gas stations
also use them bare around their front windows. These usually run
on 12 V and each one has 3 LEDs and a resistor in it. They come
on a string with a few inches of wire between each module; stick
several modules parallel to each other on a metal plate and that's
a lamp. Examples here: https://www.allelectronics.com/category/340800/leds/light-strips/1.html
5. Buy some of the LEDs that come assembled on a flexible strip or
tape. You can cut the tape every 3 or so LEDs (it's marked) to get
whatever length you want. Stick some of this to a plate, or wind
it around a piece of pipe, to make a lamp. Some examples at the
link above, plus these are all over Ebay, Amazon, etc.
If you want a bunch of them in a small area, these are IMHO a
little harder to use than the sign modules, because you either need
to fold/wind up the strip, or cut it in several places and solder a
lot of jumpers. The sign modules come with the jumpers already
installed.
Standard disclaimers apply: I don't get money or other consideration
from any companies mentioned.
Matt Roberds
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