Comment by Jack Crossfire on September 13, 2008 at 3:02pm

Seems the through hole diodes all have stripes on the lower voltage side and the LEDs all have longer leads on the higher voltage side. I never remember the lead length because they're always recycled LED's.

Comment by bGatti on September 15, 2008 at 11:18am

http://images.google.com/images?q=electrolitic%20capacitor&sourceid=navclient-ff&ie=UTF-8&rlz=1B3GGGL_enUS240US240&um=1&sa=N&tab=wi

http://images.google.com/images?um=1&hl=en&safe=off&rlz=1B3GGGL_enUS240US240&q=diode&btnG=Search+Images

Both Diodes and Capacitors have long market the negative terminal.
One could say LED's are market by "cutting" the negative lead "Shorter" - so that's really not a convention.

Ground is often the presumptive basis for electrical systems, with the "positive voltage" being the variable, interesting, measurable and inconsistent value.

Comment by MattTay on September 16, 2008 at 12:35am

There's no standard for part marking. You will only get a pin 1 designator. From there, you have to refer to the spec sheet. Your LED did have a pin 1 designator. You just don't know if pin is is anode or cathode :)

If you use a sot23 LED, you'll never have to check polarity again. Ever.

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