LED Driver sizing query/confirmation

What matters with an LED is the current flowing through it. On a basic setup, this is limited by using a series resistor. Pukka LED drivers use electronics to achieve the same thing. Some pulse them to allow a higher perceived brightness.

If they are small LEDs where efficiency isn't an issue, series resistors are the easy way to go. Either one per LED wired in parallel, or one shared with several wired in series.

In article , Cordless Crazy writes

Kit implies that the LEDs are already connected in some kind of series/parallel arrangement and without knowing the details of that it is not possible to advise the best way to connect them up.

Are these lengths of LEDs on flexible tape, or something else? More info or a link to the kit and you'll get more reliable information.

A white LED will normally drop about 3V so the norm is to run 3 in series off a 12V dc supply and then use a series resistor to get the current right.

On a separate note, are you ever going to get decent access to this newsgroup instead of using that third rate ripoff of usenet that is diybanter? They rip our content without permission and make money off the sponsored and affiliate links. IMO the worst possible kind of leeches.

There isn't the necessary info here. Your best bet is to power a set up and measure the v across and i through one of the LEDs.

NT

As long as they are wired back individually to the trafo which would suggest 12V per LED.

That sounds about right for a single LED with a resistor soldered on its leg.

CCTV PSU`s are available in handy packaging, at sub 10W any 12V wall wart will just about do.

Just keep the 240V bit dry and out of reach.

Cheers Adam

Oh so THAT's why cheapskate car manufacturers make the tail lights flicker.

You know, those cheap brands like Mercedes & Audi...

Andy

It's the same reason HID headlamps are blue-white. To quote one of the manufacturers, if they made them the same colour as regular headlamps, no one would know you'd spent £1000 on them, so no one would spend £1000 on them, and they wouldn't sell them.

Nothing to do with the emission spectra of the gas then.

Lots aren't these days. Mine if anything are a touch green.

You can make that (almost) whatever you like, depending how you dope it.

I'm not sure they are. It's just we're so used to yellow lights... Anyone like to compare some with daylight?

And _some_ manufacturers can make non-flickering LED tail lights. You can recognise them by the fast on-off time. My high-level brake light is LED and is noticably faster than the others.

I always thought the real reason they flicker is that they use that to reduce brake-light brightness down to tail-light levels, and only fit one set of LEDs.

Cheapskates.

Andy