Very Basic Question - Electronic Circuits Projects Diagrams Free

Duke_76 · 30th January 2004, 09:13 AM

I am wanting to change the LED's in some alarms I have.

I have ordered some blue leds with a cathode and anode connections. The board that they need to be connected to has two wire sone red and one black.

I am persuming that the black wire is negative and the red wire is postive.

The question I have is to what does the cathode connection on the led get connected to and vice versa.

many thanks

McGuinn · 30th January 2004, 12:39 PM

Cathode - Neagtive (Short lead on LED) (black).
Anode - Postive (Long lead on LED) (red).

Are you sure that the blue LED will work in place of the LED? They have a voltage drop of about 2.5v over Red's voltage drop of ~1.6v.

http://www.allaboutcircuits.com/vol_3/chpt_3/12.html

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

30th January 2004, 09:13 AM	(permalink)
Duke_76	Very Basic Question I am wanting to change the LED's in some alarms I have. I have ordered some blue leds with a cathode and anode connections. The board that they need to be connected to has two wire sone red and one black. I am persuming that the black wire is negative and the red wire is postive. The question I have is to what does the cathode connection on the led get connected to and vice versa. many thanks

30th January 2004, 12:39 PM	(permalink)
McGuinn	Cathode - Neagtive (Short lead on LED) (black). Anode - Postive (Long lead on LED) (red). Are you sure that the blue LED will work in place of the LED? They have a voltage drop of about 2.5v over Red's voltage drop of ~1.6v. http://www.allaboutcircuits.com/vol_3/chpt_3/12.html