greetings,
I have 5 accesory switches. I would like to light up a red led when one of the 5 switches are active. The first switch to be active will light up the red led. Any of the 5 switches can light up the red led. How can | wire this so that the light switches on when one or more of the 5 switches are on.
regards.
You will need 5 diodes available at radio shack. I have no idea what the radio shack part number is but the actual number of the diodes is 1n400X X being any number from 1 to 7. You will have to connect 1 diode to each switch. Connect the anode of the diode to the wire that gets hot when you turn the switch on. Connect the cathodes of the diodes together, and this will provide you with 12V output anytime any one of the switches are turned on. If you DO NOT have a 12 Volt LED you will need to install a resistor in series with the LED to keep from burning it up. A 560 ohm resistor will do the trick.
https://www.the12volt.com/diodes/diodes.asp
That's exactly what I was thinking of but what voltage will I obtain if 2, 3 4 or 5 switches are turned on? Will the output still be 12 V?
I think what I'm looking for here is a way to limit the output to 12 volts. Either through a resistor or some kind of voltage controller. Another option would be to use relays and mimic a "or gate". Problem is that I am an electronics rookie and I do'n know how to design this kind of circuit. Any input would be appreciated
thanks.
The voltage won't change if you have more then one on, and the resistor will limit the current.
-------------
Kevin Pierson
In that case, I'll try the diode and the 560 Ohm resistor
thanks.
Thanks for the help i am an idiot
you were correct from the start, BTW, that was a typo. I understood the 1 diode per accesory. I tested with 2 switches and this works fine without any resistor . I don't have any resistors on hand right now so I limited my testing to 2 switches. As for the resistor, I've seen two 560 ohm resistors: 1/4 watt and 3 watts. Which do you suggest? The 4 switches are powering my 4 relay coils for fog lights so they\ll be hooked up to probably a 5 or 10 amp connection.
regards.
If it works fine without any resistor then you must have a 12vdc LED, otherwise the LED would have been really bright for about a second and then it wouldn't light any more.
If you don't need a resistor with the two switches you won't need one at all. The important thing is to use the diodes to keep your isolation between relays. The resistor is simply to protect the LED from an overcurrent situation.
-------------
Kevin Pierson
As Kevin stated above you must have a 12 volt LED. If in the future you have a low voltage LED that requires a resistor, the 1/4 watt will be fine.