Firing 3 LED's using two switches and 3 wires

[Dave2131]

I know the title is a title weird, but here's what I'm trying to do:

My church has a need for for a "system" where the choir director can use a remote (wired - not wireless or IR) to signal the audio man to turn on music, and to turn the volume up or down.

What I want to do is have a pushbutton switch for the music "ON" LED (LED 1). Then if there was some type of momentary toggle/rocker switch that I could use where the director could push the switch in one direction (up) and fire the "Volume UP" LED (LED 2) and then release back to the mid position to switch off LED 2, and press in the opposite direction (down) to fire the "Volume Down" LED (LED3). The volume switch I would like to be a momentary type of switch so that they can hold it until the volume hits the level they are looking for and can just release the switch.

I will be powering the system with a 12vdc supply (wall wart).

My problem I'm running into is that the existing wire available (XLR Cable) is a 3 wire cable, and I would need 4 wires to do this easily. Does anybody know of a way to do this, or should I just tell them all we can do is a 2 LED system (music on & volume up)?

Any help would be appreciated.

 

[ChrisQ]

K I'm a noob so wait for better advice, but how about putting a potentiometer on the volume LED? Then the director could signal how loud or soft he wants the music. The brighter the glow the louder he wants it.

 

[duke37]

If you use an AC power supply, you can rectify to get a positive and negative output. Either or both can be switched to a single wire. Rectifiers (diodes) at the receving end will divert the signal to the LED required, With 3 wire (2 + screen?) cable one wire would be reference (ground) giving 2 spare wires and 4 possible operations. If the cable is 3 wire +screen, you do not need this exra complication.

 

[poor mystic]

Hi there Dave (cheesy grin)
There are lots of choices here.
For instance you could use a flashing led to attract attention and get your sound guy to turn the music on, and you can leave the same led on "steady" for as long as you want the music on.
Then the other led can be used to ask him to raise volume. I'd flash that one, too.
If you want the music down a little you can interrupt the first led, which has been going steady. When you want the music "off", switch the first led off.
So there are 2 ways you can use each led: "steady" and "flashing". You have 2 led's so you have 4 signals all together that you and the sound guy can agree on.
The big factor here is the human factor... you and the sound guy will need a certain amount of practice with your signalling system, which you can design for yourselves.
Do you need to know how to make a flasher circuit for the led's?

 

[duke37]

With luck, the diagram may help.