Posted by: andygjones
electronics question - 30/12/2001 07:40
I am currently building a docking unit for my empeg and wanted to include a power LED on it. I have no idea when it comes to electronics so was wondering what i need to do? Can i just get a 12V led (empeg power unit is 15v) and run it straight from that or will i need any resistors or anything? i really dont have a clue :)
Thanks
Posted by: TommyE
Re: electronics question - 30/12/2001 08:08
Hello,
If you get hold of a normal LED, they'll normaly draw about 15mAmps, and they will normally need around 2Volts.
So you can use the following formula to calculate the size of the resistor needed.
R = U / I
R = Resistanse of your resistor. (What you will calculate)
U = Voltage over the resistor, around 10volts if you have a 12volts supply. (Since the LED will use 2 volts)
I = 15mAmps. (Aproximate value for a LED)
R=10/15ma = 666,67 Ohms
Put a resistor of 670Ohms in serial with the LED and connect it to a 12V supply.
I guess a 1Kohm resistor will be OK for 12-16V supplies, might be easier find around too.
Hope this helps.
TommyE
Posted by: andygjones
Re: electronics question - 30/12/2001 15:14
thats great! thanks very much. Think ill try and learn some basic electronics sometime. Will post some pics of the docking unit once ive finished it.
Thanks again.