How to make an LED light regardless of polarity?

Just put two leds back to back so they share the same current limiting.

Works!

No way I know of. You do know you can get dual Leds in one package don't you?

Sorry, I wasn't clear: I need to light *one* LED regardless of polarity. Two won't do; the spec allows for just one.

Thanks,

- Joe

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You can also get the four diodes (bridge rectifier) in one package.

I think you mean in parallel (so they share the same current limiting

what is your source voltage? use a bridge rectifier and connect the LED to the + and - terminal.

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You could use a two-colour LED--but then the colours would be different in different polarities.

Cheers,

Phil Hobbs

9 VDC, though of course I use a current-limiting resistor.

Thanks, that's exactly what I was looking for!

Best,

- Joe

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Amazing! a bridge rectifier _is_ four diodes, which you said you had
no room for...

And four diodes are usually smaller than a bridge rectifier. Though I haven't looked at SMD models that may be out there.

Thomas

Try to find those two-color LEDs that have two different color LEDs in one LED package, those two are installed on different directions. Installing such LED would make the LED to light on different colors on different polarity power, and third (combination of those first two) when AC is feed to it. This could be one option to consider if you specification allows it.

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But it's one component instead of four. Is it so amazing that I have room for one more component (possibly even two), but not four? Or have I missed something?

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An 1n914/1n4148 with leads is very small and 4 of them mounted behind the LED will make it a bit longer but not wider.

Thomas

--- I think you've missed something.

You said, in essence, that you didn't have room for four motorcyles, but that a Honda Civic would be fit in the same volume.

That is, not that there aren't any, but I haven't seen any full-wave bridges in packages smaller that four tiny diodes, and they're both four diodes. There is another possibility, though, and that's that there are lots of tiny dual diodes out there, so you could make up your bridge that way if you could fit two of them in there and the full-wave bridge wouldn't.

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"Joe Strout" schreef in bericht news: snipped-for-privacy@comcast.dca.giganews.com...

Have a look at the size of the components mentioned. A diode bridge requires (much) more space then four small diodes (1N4148 for instance.)

petrus bitbyter

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"Michael A. Covington" wrote in news: snipped-for-privacy@mustang.speedfactory.net:

yup!!! an example is old radio shack part number 276-065 commercial equivalent is 369HHd. A single jumbo LED with common cathodes and two separate anode leads.

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The Siemens BAV99S has 4 doides which can be bridge connected in a 6 pin SOT-363 package which is about 2mm square.

Thank you all for your input. I've already got some bridge rectifiers on order from Mouser, but if none of them fit the task, I'll try four separate diodes (or two dual diodes) instead.

Thanks,

- Joe

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