Discovered my red clear led are reversed

[Nic]

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?

 

[BuddytheReow]

I usually go by lead length rather than the shape of the bulb. Still, good catch!

 

[Nic]

I usually go by lead length rather than the shape of the bulb. Still, good catch!

I better start doing this too!

 

[Robert]

In the event that the leads are already clipped ...

 

[spi]

I usually go by lead length rather than the shape of the bulb. Still, good catch!

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]

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

 

[HamishR]

I had a bunch of those a few years ago too. I rarely use LEDs now so maybe I still do have some!

 

[Nic]

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).

Lately, I would just pick one and feel the flat surface using my fingers ... had not used the red ones in builds lately.

 

[Nic]

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.

 

[jimilee]

That’s been a pretty common experience with Tayda. I always use my DMM on the diode setting before I wire them in. You can only desolder so many LEDs before you’ve had enough.

 

[jwin615]

That’s been a pretty common experience with Tayda. I always use my DMM on the diode setting before I wire them in. You can only desolder so many LEDs before you’ve had enough.

Didn't you have some terrible fits from some blue LEDs several years back?

 

[Nostradoomus]

that's probably the prompt to DMM check now lol

 

[jimilee]

Didn't you have some terrible fits from some blue LEDs several years back?

I did from UV LEDs, not sure if I did with blue, but I have a terrible memory.

 

[hamerfan]

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.
View attachment 89560

short the wires on the large plate and you are good to go!

 

[Nic]

short the wires on the large plate and you are good to go!

Well, they work but just not the way I thought they would. I was just surprised by the discovery. When I used them in builds, I would just assume I put them backward in the first place, and technically, it's true. Now I know better.

 

[hamerfan]

Well, they work but just not the way I thought they would. I was just surprised by the discovery. When I used them in builds, I would just assume I put them backward in the first place, and technically, it's true. Now I know better.

I had the same issue with blue colored led when i used the shorter wire as cathode. I did not solder it, because i had to check the length out of the box first.
The advantage of the clear led is that can check the size of the plates for a double check.

 

[eatkinola]

The advantage of the clear led is that can check the size of the plates for a double check.

The anode and cathode plates should also be visible on tinted LEDs. I have to remove my glasses from these tired eyes to see them, but the plates are visible.