LED Lead Length; or why I have trust issues

[untamedfrontier]

So in spite of me not worrying any more about LED polarity, mostly in thanks to this thread where MightySmallElectrons said "stick the long lead in the a-hole", I got some blue LEDs from Tayda that go both ways. I'm really really really glad I hadn't installed this one yet and was only testing.

I have to wonder how many people joined the backwards LED club because of these...

 

[Robert]

The larger metal part inside the LED is always the Cathode.

That's a more reliable way to identify than looking at the lead length.

 

[music6000]

Here is another way to Identify most Led's polarity:

 

[Jovi Bon Kenobi]

If LED lead length is the goal
Perhaps one should take a poll
Is the long lead the anode
Or the short lead the cathode
I guess Tayda is the true a-hole

 

[Betty Wont]

Here is another way to Identify most Led's polarity:

View attachment 6804

Most, but not all. For example, the ultra bright red water clear from tayda have always had the flat at the anode. I always measure LEDs that are new to me with my meter to be sure.

 

[zgrav]

I usually get the board assembled and wired, then put the LED in the holes to see which way it is oriented to turn on when the board is switched on. I try to anticipate the right lead placements, but I not surprised if it needs to be reversed.

 

[PapaBear]

I keep drained 9v batteries on my bench so I can verify it works and is the color I want, which would verify orientation as well

 

[dlazzarini]

I do the same with my spent 9volts

 

[spi]

My multimeter in diode/continuity mode can check led orientation--I assume most models of multimeters can do the same.