3PDT stomp switches - do they have a polarity?

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Green Bean

Joined Mar 31, 2017
126
I just built this guitar pedal kit:

https://github.com/tardate/LittleArduinoProjects/tree/master/Electronics101/GuitarEffects/DelayKit

Of course, it doesn't work. I turned it on, the LED blinked, and nothing happened. I quickly turned it off and tested the LED to make sure it did not short out. The LED is fine. So I did some snooping around and noticed the 3PDT switch had a white dot on one side. Does the dot mean that side is the front, and the switch has some kind of polarity?

The switch looks like this:

https://tse4.mm.bing.net/th?id=OIP.8dbMhpXl8JV-aedyZbjfJgEBEs&pid=15.1
 

Dodgydave

Joined Jun 22, 2012
11,234
The wipers (Com)for the switches are in the centre, and the end terminals (NO. NC.)
are at the ends , the switch wipes from the end of the pcb to the centre.
 

philba

Joined Aug 17, 2017
959
I'd just buzz out the connections on that switch, so you know what it's actually doing. In general, I do that every time I build something with switches. Way back in the mists of time, I built a project and it didn't work. Traced through everything and nothing was incorrect. Then I checked the switch and, sure enough, it was faulty.
 

ian field

Joined Oct 27, 2012
6,536
I based my answer on his pcb layout, the centre pins are the wipers.
If its a kit, you'd hope for the right switch in there, but gathering parts can end up with a slightly different design.

A lot of biased toggle DPDT switches have the wipers at one end.
 
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