This week-end, I made a discovery. On a batch of 5mm clear red LEDs I bought from Tayda a couple years ago, the flat side is the anode! I was breadboarding a 555 game buzzer circuit and my leds would never go on. I thought I was going crazy. I had to stop and test my leds individually and made the discovery. Anyone else had this problem?
Discovered my red clear led are reversed
- Thread starter Nic
- Start date
BuddytheReow
Breadboard Baker
I usually go by lead length rather than the shape of the bulb. Still, good catch!
I better start doing this too!
spi
Well-known member
Yeah, my follow up question is to know if the leads are also reversed, because that's what I always go by. I've never even considered using the flat edge (although I know it's there it just doesn't occur to me to notice it).
drew.spriggs
Active member
Yep. I got dozens of them, and only figured out when the classes I was teaching had working pedals but no LED.
It's very annoying
It's very annoying
Going by the leads would be fine... but what with the plates ?
Here are 2 red on the left and a green on the right. All have flat side on the left side... so they should all have the flat for the cathode, but the red ones really are reversed. I might just have to test them again.
Here are 2 red on the left and a green on the right. All have flat side on the left side... so they should all have the flat for the cathode, but the red ones really are reversed. I might just have to test them again.
Didn't you have some terrible fits from some blue LEDs several years back?
Nostradoomus
Well-known member
that's probably the prompt to DMM check now lol
jimilee
Well-known member
I did from UV LEDs, not sure if I did with blue, but I have a terrible memory.
