I bought some Micro-mini LEDs from Miniatronics. As the connectors are same length I can't tell anode from cathode. I sent an email to info@miniatronics.com but the server returned it. Can anyone can tell me how to tell which one is the anode (+)?
Guy
Modeling CNR in the 50's
There should be a flat on one side - that's the cathode (-)
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Guy Papillon I bought some Micro-mini LEDs from Miniatronics. As the connectors are same length I can't tell anode from cathode. I sent an email to info@miniatronics.com but the server returned it. Can anyone can tell me how to tell which one is the anode (+)?
It is a bit odd that the leads are the same length, as that is one of the ways of identifying the anode and cathode. The flat spot is the cathode (K), also if you look at the structure, the anvil, which looks like a flag, and is usually larger, is the cathode.
There is a picture here that shows the details.
Those are very small LED 1,5 mm diameter on a square colored base. Then...
Randy : there are 4 flat sides
Betamax : can't see the anvil at all, because of the color and size.
So I decided to flip a coin and choose one of the connector to be the anode. I soldered the resistance to this wire. I hit the good one. Now I know. Too bad that the manufacturer doesn't give instructions either on the package on on is site.
There's a mark or notch or somethiong on one side, there always is. It has nothign to do with Miniatronics, it's an industry standard. For those types, it;s usually a color strip on the cathode side.
Of course, trial and error works fine, as long as you have a resistor. It doesn;t matter which side the resistor connects to. If it lights, you have the polarity right, if not, flip it.
Your picture is a little fuzzy, so it is hard to really see the details. This is not your usual coaxial LED, this one has radial leads. It should have a line, a dot or dimple, or a notch to indicate which lead is which.
From what I found, there should be a line, a dot/dimple. or one corner will have a chamfer. That will be the K cathode connection. If you don't see one, turn it over and look for the dot. Just rig up a test circuit with a series resistor and try it, it will either work or not.
Flip that LED over. One half of the green should be painted silver. That's your cathode identifier.
Sounds like you need to get an Optivisor. There will be an identifying mark on the device.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
On those LEDs, there are '+' sign tips sticking out on one lead (the right-hand lead in your photo) to indicate the positive side.
Now I am more confused than ever.
Cacole ; Can't see any "+" even with a Optivisor (richg1998)
SmithSr : Yes, one half is painted silver BUT as I wired the resistor to this side and that the LED lit I assumed it was the anode. I thought that if I placed the resistor on the cathode, the LED wouldn't lit. Am I right?
Doesn't matter which leg the resistor goes on - all that matters is the correct polarity.
You guys are making this way more involved than it needs to be. Attach the resistor to either leg - test with your DC supply - if it doesn't light, switch your leads - mark the positive lead with a marker - done.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Tank you all.