Transfer a DPDT to a 3PDT

[MixmasterFred]

Hello, I built the Maestro sample/hold from guitar gadget and it works fine. It uses a DPDT toggle switch to go from one Fx to the other. I would like to do it with a 3PDT footswitch instead and add a 2 color LED to it to know which fx is on. So my question is how do I do it?
Thank you!

[Chillums]

Do you already have the dual color LED?  Do you know if it's a common anode or common cathode type?  Once you tell me which kind you have a will draw in the mod on the picture you posted.

[MixmasterFred]

I have the LED, It's a cathode I think...

[antonis]

Connect Common Cathode leg to GND..
(as close as physicaly possible to power source ground..)
Connect +9V + CRL to switch middle lug..
Connect Red & Green Anodes to switch upper and lower lug respectively..
(CRL value depends on LED current demand - for a 5mm LED, a 1k5 resistor should be OK..)



P.S.1
In case of common positive (Anode) simply reverse GND & +9V wiring..
(switch GND between Cathodes while maintaining 9V+CLR "common"..)

P.S.2
Unless, of course, your particular bi-colour LED is an antiparallel configuration one..
(only two legs..)

[MixmasterFred]

Thank you for the reply, how do I transfer the rest of the wires to the switch, wich goes where? I'm really lost.

[antonis]

I'm really lost.

Me too..

Use 2 of 3 columns as per DPDT switch wiring and wire 3rd column for bicolour LED indicator..

P.S.
Am I missing something..??

[aleks_tedstone]

The best way to think of DPDT and 3PDT is as either 2 or 3 SPDT switchs next to each other, isolating the circuits but all activated at the same time.

Using antonis suggestion (assuming you have the type of 2-colour LED described), you simply wire 2/3 lines of your 3PDT as shown in the GGG schematic, and then add the led to indicate which way the switch has been thrown:


Make sure your current limiting resistor (CLR) is the right value for your LEDs, eg. 1k5 as suggested, and put it between the +9V point on the board and the anode (the switch may also be between them). The power jack may be closer than the board +9V, either will work!

Hope this helps!

[antonis]

Good try aleks_tedstone but now you've confused OP more..
(as it is, rows and columns are mismatched..)

[aleks_tedstone]

  Sorry!

Hopefully this helps a little? Imagine my (terrible) diagram lined up like those shown below:



Surely 3 and 4 in the original DPDT image are the commons?

[antonis]

Surely 3 and 4 in the original DPDT image are the commons?

Can't be sure without tracing PCB wiring connections but, in general, yes..
(it's a kind of common convention to draw lugs flat dimension horizontally..)