3P2-4T Rotary Switches

Started by kyledix, October 21, 2014, 02:04:36 PM

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kyledix

I'm working on a clone of the Death by Audio Robot on veroboard (link to vero layout) and I am having trouble with understanding the rotary switch configuration.  The layout calls for a "Rotary Switch 4P3T" as the mode selector (switches between normal, octave up, octave down, arpeggiator), but I got a 4P3T (this one specifically) which arrived looking like this.  So I think the switch type was written incorrectly and I need a 3P4T instead of a 4P3T.  Can anyone help me with a sanity check on that?

So I bought this from SmallBear instead, but it doesn't look like the schematic either (at least on the outside).  If this is the correct switch, can anyone tell me how it corresponds to the vero layout above?  You may be able to see in the picture from smallbear that it looks like it has 4 pins , then a plastic separator, then 2 pins, then 4, then 2.  But do the throws simply correspond to the center pin on the inside based on which is closer?  Or does it have some other layout, for example, two of the throws only have 2 pins?

I appreciate any input you have.

Luke51411

The switch called for on the vero looks like a 3 pole 4 throw to me and what you have a is a 4 pole 3 throw.

digi2t

Luke is correct. The vero is wrong, it's a 3P4T that you need. The "P" is for Poles, and the "T" is for Throws.

Poles = Connection point that may be common for a series of points.
Throws =  Number of positions (clicks).

On the rotary switch that you have, the connections close to the center represent the Poles. The outer rings of connections are the Throws. Since there are 12 points, and 4 poles, you only have 3 throws. The Robot requires 4 throws, hence 12 points, and 3 poles, as illustrated in the mislabelled layout. A PITA for sure. Order a new switch.
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kyledix

Thanks for the help.  Please read the second paragraph of mine... I bought a second switch that I am hoping fits the bill.  It's a "3P2-4T".  I am assuming this means it can be configured for anywhere from 2 to 4 throws?  Will this work:  http://www.smallbearelec.com/servlet/Detail?no=46 ??  I'm not sure how the outer 'pins' map to the throws.

Thanks!

armdnrdy

If your switch is labeled like the one I have in front of me...

You should have A, B, and C in the middle, and pins 1-12 on the outside.

Pin A goes with pins 1-4
Pin B goes with pins 5-8
Pin V goes with pins 9-12
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duck_arse

the smallbear switch you sent me to look at is correct. it is 3 poles, and can be 2, 3 or 4 position/throws. get your switch, and turn the shaft all the way anti-clockwise. now remove the nut and washer, and there will be another washer, with a lobe sticking off it. lift this washer up, rotate it until the lobe is pointing to the second hole from ccw, then drop it in, quickly put the other washer and the nut on, and you have a three position three pole switch.

unless you want the fourth throw, in which case use the third hole from ccw. rotate the shaft as you count clicks, it should definately be less than 5, being the fifth number be reached, etc.
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