LED Hookup

[biferi]

This is the LED I have
https://www.jameco.com/webapp/wcs/s...Id=10001&ddkey=http:StoreCatalogDrillDownView

It has 4 Pins and they told me the corner with the Notch is the + Pin and all the other Pins are the - Pins.

But when I put my Black wire to the Notch Pin and the Red wire to the other Pins it wont Lite.

But if I put the Black to any other Pin but the Notch and the Red to any other Pins it does Lite.

So what is the Notch corner for?

 

[MikeMl]

The notched pin is the Cathode, the other three pins are the Anode. To Make the LED light, conventional (not electron) current flows into at least one of the Anode pins and out of the Cathode pin.

Remember that LEDs are current-operated devices; not voltage-operated. The external circuit must limit the peak current to less than 40mA.

 

[biferi]

Well my Battery Pack holds 3 Dabble A Batteries in Series witch will give 4.5 Volts.
And my LED is Rated at 3.5 Volts and 40 mA.
So I am using a 1,000 Ohm Resistor to make the Current 3.4 mA and it works.

 

[audioguru]

The datasheet shows that the pin nearest the notch is the cathode (the negative wire).

If the 3 Dabble (double) A battery is new then its voltage is 4.5V to 4.8V.
The LED "might" be 3.5V. All LEDs (except this one?) have a range of forward voltage).
Then the 1k current-limiting resistor has a voltage of 1V to 1.3V across it and the current is only 1mA to 1.3mA, not 3.4mA.

 

[biferi]

Yes my 3 Dabble A BAT. Pack puts out 4.5 Volts because the Batteries are in Series.

And my LED needs 3.5 Volts at 40 mA.

I am useing a 1,000 Ohm Resistor and it works the LED Lights.

 

[KeepItSimpleStupid]

Aside:
There is youtube video about the Micro$oft support scam which I've been called at least a half dozen times. I was in a playful mood one day, so i decided to play along until they wanted to download a "remote access" kind of program. Then I said i was running Linux. He hung up. Then I did a call trace and reported the successful trace to the FTC (Federal trade Commission).

The youtube guy was making fun of the way "w" was pronounced and saying you want me to type dabblu dabblu dabblu for www. It was so funny.

 

[audioguru]

Your LED has a current of only 1mA so it is fairly dim.
If the battery is not new and is 4.5V and if the LED voltage is 3.5V then the resistor has 1V across it. For the LED to be at its maximum 40mA current then the resistor value should be 1V/40mA= 25 ohms which is not a standard value. Use 27 ohms.