Replace a 3way switch by another, sounds simple ?

Hye Everyone,

Sorry in advance for my English (I'm French so... well you know), I'll make my best to be understood.

I'm doing an alternative version of the "famous" DSO Shell mini oscillator,

I've got a "simple" problem, see below :

The main idea :

On the One Hand I've got a PCB with a 8pins, 3 ways switch. On the other Hand I've got a best 3 ways switch (with a beautifull blue led) but with only 6 pins (+2 but only for the blue led power)

The aim is to replace the 8pin switch by the 6pin switch (all détails will come in time, be confiant)

Technical datas :

8 pin switch :

New 6 pin Switch :

Global Electronical Shem :

All caractéristic and shems are included in the links

Where the swith should be (8 broches => 6+2) : Note, the two big holes are made to fix the switch but are connected to "nothing".

The idea here is to wire the new switch but what are we supposed to do with the to remaining holes ?

Global View of the pcb board… (the switch should be on the upper right):

Link of the object concerned by this procject. :

To conclude, I know the "new" switch is not really good for my purpose but I definitively want to use it so I'm searching for a way to adapt it

Thank's for your help

Ps : At this time, I thought of wiring it as below :

Switch 1 Switch 2
Pin1 N01
Pin2 Nc1 (defaut)
Com C1 + C2
Pin3 N02

And, for the NC1 concern (wich should be "open" when NO2 is "closed"), I thought to add a mosfet transistor to NC1 pin driven by NO2 pin.

As below (main idea of the shematics) :


You want to replace a 3 way switch with a two way switch with zero position.
That is not the same thing and so forms your real problem.
You are missing 1 position with the new and beautiful switch.
The original switch doesn't have a neutral position where none of the pins are connected to any other pin, right ?

You can do this by utilizing a pair (so two) of DPDT relays, switched by your switch on the front.
Relays need a power supply so that may be a problem with this.
But the advantage is that you will remain the same kind of separation you have now, which is (or may) not be the case with some FET solution like you suggested.

Do make a diagram before you wire this, and check it at least twice so you are sure the right pins on your PCB will be connected with each other.

3 way switch usually is referred to switch used to turn light ON/OFF in the house from two different places, you need 3 position switch. Google; 3 position switch with LED, 3 position rorry switch with LED, but with 2 seperate swithes ( your 8 pin switch ) will be hard to find, can be done with additionl circuit with two IC - CMOS 4066.