I am having trouble reading the schematic for the C&K L204011MS02Q DP4T slide switch (datasheet here). In particular, I am trying to identify the "common" pins so that I can wire this switch up correctly on my PCB.

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Looking at the schematic for the L202 DPDT switch in the same datasheet, I can see that pins 2 and 5 are the "common" pins - in each of the two available slide switch positions, the switch is connecting pins 2 and 5 to other pins (pins 1 and 4 or pins 3 and 6, respectively).

enter image description here

In the schematic shown in this datasheet for another DP4T switch, the C&K SS-24E06-TG 5 (P), I can see that the center pins of each row are the "common" pins - in each of the four available slide switch positions, these center pins are connected to other pins.

enter image description here

Returning to the L204 DP4T switch, which pins would be the "common" pins? Many thanks for any help - I have searched far and wide on the internet and consulted with two coworkers and still can't seem to figure this schematic out. Also, I don't currently have access to the switch to buzz the pinout manually.


3 Answers 3


The black part slides in to any of 4 different positions, making connections as follows.

Pos A: 1 to 2 and 6 to 7

Pos B: 2 to 3 and 7 to 8

Pos C: 3 to 4 and 8 to 9

Pos D: 4 to 5 and 9 to 10

So, it looks like some Boolean algebra needs to be worked out to achieve at best a single pole 4 throw switch.

Is enough for your purposes? You might want to go to a different type of switch. From what I see, the manufacture called it a DP4T switch, but it's really a 4 position slide switch with sequential contacts.

  • \$\begingroup\$ I suspect you may be right. The manufacturer's naming is unfortunate because people looking for a DP4T switch find this one and people looking for a 4 position slide switch with sequential contacts might not find it. I am in contact with the tech team at Digikey and will provide an update/confirm the answer once they get back to me. \$\endgroup\$ Oct 4, 2019 at 12:05
  • \$\begingroup\$ So I ended up ordering one of these switches and buzzing the pinout manually with a multimeter. The pinout was exactly as you described, i.e., a four position switch with sequential contacts. I ended up selecting another DP4T switch that offered dedicated common pins. Thanks for your help! \$\endgroup\$ Oct 17, 2019 at 2:25
  • \$\begingroup\$ Thanks man. Keep on keeping on! \$\endgroup\$
    – user233390
    Oct 20, 2019 at 14:50

I was looking at the same switch for the same purpose. Finally I figured it out after a couple of hours trying!!!

  • A to pins 2 and 9.
  • B:
    • B1 to pin 1,
    • B2 to pin 3,
    • B3 to pin 8,
    • B4 to pin 10!

One source, 4 destinations!


I read this as:
Contacts for pins 3 and 8 are wider than the others.

So when the switch is all the way to the right, Position 1, Pole A pin 1 goes to pin 3 and Pole B pin 6 goes to pin 8.

Sliding one to the left, Position 2, then Pole A pin 2 goes to pin 3 and on Pole B pin 7 goes to pin 8.

Sliding again to the left, Position 3, then Pole A pin 3 goes to pin 4 and for Pole B pin 8 goes to pin 9.

Sliding all the way to the left, Position 4, then Pole A pin 3 connects to pin 5 and Pole B pin 8 goes to pin 10.

Pin 3 is the common pin for Pole A, and pin 8 is the common pin for Pole B.


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