Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: cassf1 on May 24, 2010, 06:56:25 PM

Title: LED's and P44 switch
Post by: cassf1 on May 24, 2010, 06:56:25 PM
Hi

I have a P44 switchand want to use it for some LEDs, one side to power a spot light and the other for navigation lights.

My question is running from 12v is ok to put 12v into the switch then use the resistors after switch but before LEDs? Is the resistor on the positive feed?


Im using 4 red 2.1v  25mA with a R150 and 4 green 3.3 25mA 3 of these using a R100 and one using a R360 from one output on switch and the other output switch to power a single white 3.3v 25mA with a R360

Values worked out using LED calculator
Title: Re: LED's and P44 switch
Post by: Subculture on May 24, 2010, 07:32:39 PM
It doesn't matter which side the resistors go, so long as they are there.
Title: Re: LED's and P44 switch
Post by: cassf1 on May 24, 2010, 07:36:34 PM
thanks for your reply i wondered why some LED calculators showed on pos and others neg
Title: Re: LED's and P44 switch
Post by: Rex Hunt on May 24, 2010, 09:27:30 PM
The resistor works like a tap on a hose........doesn't matter where in the hose you put the tap....it still controls the flow of water from the end of the hose!

Rex
Title: Re: LED's and P44 switch
Post by: malcolmfrary on May 24, 2010, 10:47:55 PM
thanks for your reply i wondered why some LED calculators showed on pos and others neg
They have to put it somewhere.  Giving people a choice confuses them.  Just make sure that all the LEDs are wired the same way round, resistors don't care.
Title: Re: LED's and P44 switch
Post by: FullLeatherJacket on May 24, 2010, 10:50:13 PM
I always connect the resistors on the same side of the relay as the LEDs and right close up.....................but only because it's easier to draw  8)
FLJ
Title: Re: LED's and P44 switch
Post by: cassf1 on May 25, 2010, 12:12:35 AM
thanks everyone will go ahead now and hopefully wont start glowing red or look like a smoke machine