How to wire pot with rotary switch?

Thread Starter

TheLaw

Joined Sep 2, 2010
228
Hello,

I have a quick question (I hope), about wiring a dual gange potentiometer that has a built-in rotary SPST switch.

I do not need the included switch. I want it to function as a normal potentiometer. How do I get it to do so? Do I permanently bridge the two SW (switch) lugs?

It's a Bourns "PTR" panel mount potentiometer. Here's the diagram:



Thanks.
 

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KJ6EAD

Joined Apr 30, 2011
1,581
http://www.mouser.com/Passive-Components/Potentiometers-Rheostats/Potentiometers/_/N-5g9h?P=1z0vkp2&Keyword=ptd902&FS=True

I saw 7 10k models listed, 3 stocked 4 non-stocked. You must want an unusual combination of features.

You seem to be thinking that there's some electrical connection between the switch and the potentiometers; there isn't. The only connection is mechanical; they're on the same shaft so the switch gets closed as the wipers on the potentiometer wafers start to move away from one end of their travel. Using the PTR902 only as a potentiometer would be unusual because of the detent at one end of the rotation but you'd get used to it.
 
Last edited:

Thread Starter

TheLaw

Joined Sep 2, 2010
228
http://www.mouser.com/Passive-Components/Potentiometers-Rheostats/Potentiometers/_/N-5g9h?P=1z0vkp2&Keyword=ptd902&FS=True

I saw 7 10k models listed, 3 stocked 4 non-stocked. You must want an unusual combination of features.

You seem to be thinking that there's some electrical connection between the switch and the potentiometers; there isn't. The only connection is mechanical; they're on the same shaft so the switch gets closed as the wipers on the potentiometer wafers start to move away from one end of their travel. Using the PTR902 only as a potentiometer would be unusual because of the detent at one end of the rotation but you'd get used to it.
Wow I'm an idiot. Someone missed those. I expected the pictures to be more alike.

PTD902______ PTR902



Just making dumb assumptions again. I did NOT buy the pot yet. Thanks for the heads up. I'll go with the PTD
 

SgtWookie

Joined Jul 17, 2007
22,230
I suppose you could do that, but doesn't the subwoofer output come as a combination of left and right outputs?

Perhaps you should explain more about the circuit you're connecting this pot up to.

You'll want audio taper pots for volume control.

Keep in mind that you need to adjust the volume at "line" level, not at the output of your power amplifier. If you try to control the volume from the power amp output, you will fry the pot - and maybe the amp as well.
 

Thread Starter

TheLaw

Joined Sep 2, 2010
228
I suppose you could do that, but doesn't the subwoofer output come as a combination of left and right outputs?

Perhaps you should explain more about the circuit you're connecting this pot up to.

You'll want audio taper pots for volume control.

Keep in mind that you need to adjust the volume at "line" level, not at the output of your power amplifier. If you try to control the volume from the power amp output, you will fry the pot - and maybe the amp as well.
Ah right. I have a board that actively combines the two L + R channels for the subwoofer and preamps the signal. It has 4 potentiometers that control volume, phase, crossover freq. etc. I will use the volume pot that the board has. But I would like a "master volume control" that controls the two L + R channels, as well as the subwoofer in one dial.

Usually I put my potentiometers AFTER the buffer/preamp, where there is only one channel (because the signals have been combined).

One question regarding running two potentiometers on the same signal. It's okay to do so, right? I bought the sub preamp/combiner board off eBay and it came with 100K pots. (Printed = "A100k") So I'd like to use the one on the board to control just the subwoofer's volume, and then I'd also like to use the master potentiometer to control the subwoofer and the satellites.

Any ideas on the best place to wire in the potentiometer? Can I attach one gange of the 4 gange pot directly to the legs of the existing potentiometer on the preamp board?

Thanks.
 
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