Some of my design work in action...

You build lighting for bus stop shelters? :-) Mikek

The LED drivers in the billboard. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

amdx wrote in news:lbrg89$gtc$ snipped-for-privacy@dont-email.me:

And British are using it? :)

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What kind of power does that thing draw?

I don't know the exact numbers, but it is in the multi-KW range. But it's "efficient" with switchers regulated to supply just the exact amount of forward drop required by each LED grouping. ...Jim Thompson

What type of LED doe a billboard use? Wattage? How is the light made uniform? curious, John B

Wow, I knew you predated them, but I never knew you actually _invented_ bricks. Awesome!

Cheers

Phil Hobbs

;-) ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

Apparently. Imagine walking or driving in that nice old-fashioned neighborhood with cobblestoned sidewalks, being blinded by a bright, garish, mega-LED billboard. Who let that happen?

We have some of those LED mega-blinding-billboards next to freeways here, and people hate them. I have fantasies of target practice...

I've heard they are considering a tax on people who actually do something. :) The writer Kurt Vonnegut suggested special ankle weights for such people, so they would move slower, and not upset others.

On a sunny day (Thu, 23 Jan 2014 09:23:45 -0700) it happened Jim Thompson wrote in :

Strange, that reminds me of Nottingham UK.

Left hand driving too, yes UK, anybody from Nottingham?

What was it you did???? that red car, your focus sucks.

crossposter!

Do you also have a constant current in the design, or do you just supply "exactly the right voltage"?

I was actually thinking about this, is there such a thing as a switching constant-current source, rather than a switching voltage source? Wouldn't that be pretty efficient?

That's a London Underground symbol on the bus stop thing. Do they use that elsewhere?

I have the MIND THE GAP tee shirt.

Funny, "Out of darkness comes light"

As in, blinding moving ads to distract drivers and blot out the sky.

Controlled currents via video. "Exactly the right voltage" is in the patent application process, so I can't comment.

The trick is the get the voltage at the tops of the LED's to be _exactly_just_enough_ that the (switching) mirrors don't run out of head-room. ...Jim Thompson

I have fantasies of target practice too >:-}

I don't like the billboards myself... but many of the things I design I wouldn't buy... like touch screen cellphones (smart-phones... gack!-)... worked on a chip design tightening up their resolution just last year. ...Jim Thompson

Sure, there is a whole raft of chips made specifically as constant current switching supplies for LED lighting.

Jon

As you might imagine, many years ago there was a clamp down on advertisements on land adjacent to motorways. Things seem to have change for the worse, with more roadside advertising and a continual reduction in speed limits to offset the dangers.

I have been near blinded by these screens running full blast at night by the M5 motorway.

Overall I am not impressed at the change in road-scape where it increases the risk of carnage.

I guess 20 seconds of googling would have told me that ;-)

Typical, they don't even drive on the right side of the road...