Mats continues his challenge of designing one PCB every week. In week 20 he came up with LEDger Led (polarity) tester:
Everytime I solder a SMD LED on a pcb I have to turn on one of my multimeters and flip it over to diode-test mode and then probe the SMD LED to see which connector is the anode and which is the cathode. The LEDger is a small PCB with a button cell battery and smd footprints that allows me to, while still holding the LED in my tweezers. just hold it onto one of the footprints and see if it lights up or not.
LED tester giveaway coming up soon! Stay tuned!!
That is good handy tool to check LED.
There’s an easier way to tell polarity on SMD LED’s:
http://lighthouseleds.com/blog/polarity-guide-of-0402-0603-0805-1206-and-most-all-smd-leds.html
Will: Maybe or maybe not. Read this article and see what the professionals say about the issue or polarity markings of smd leds. http://blog.screamingcircuits.com/2013/01/how-not-to-mark-a-diode.html
Apparently some suppliers have the “T-mark” 180 degrees reversed even among their own products. :-(
I’ve seen many variations of LEDs, especially those sold on ebay. IMHO the ONLY way to be sure is to use a multimeter or a device like this. Desoldering LEDs will mostly kill them or ruin the lens.