How do I wire a DPDT On/On switch, with flying leads to a pad on a PCB

Started by seagurt, March 01, 2017, 05:49:09 PM

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seagurt

So, to reiterate, How do I wire a DPDT On/On switch, with flying leads to a pad on a PCB to switch resistor values. I am building a Mammoth Electronics MKC1 (mini Klon circuit) and there is a mod that adds a DPDT on/on switch, that changes between 47k, and 8.2k to add more gain, or have the stock amount (47k is stock).

I am mostly confused about the flying leads to the switch... Where do they connect? I also got a DPDT board, link below

http://www.guitarpcb.com/apps/webstore/products/show/3186804

So where do I connect the leads from the PCB pad to the switch, and how do I orient my resistors on the daughterboard so that they switch. I lent my friend my multimeter, so I cant check continuity, but I am thinking the outer lugs are the 2 different positions, and the middle is ground?

Here is the PCB layout. The resistor pad I am referring to, is R15.

Thanks for reading, and I look forward to learning about this particular practice. I have a few fuzzes that I would like to add switches to, in order to change cap types and values.
Those who know the least will always know it the loudest.

Long's Law

antonis

I suppose that you need a SPDT to switch between 2 resistors and the rest SPDT ((DPDT = SPDT + SPDT) for LED indicator..

If not, plz post circuit diagram and PCB image..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

vigilante397



Leave the 47k resistor off of the PCB, solder the two resistors to the switch like this. Now just pretend the two wires from the switch are the two leads of your resistor and solder them into the resistor's pads on the PCB.

Hope this helps ;D
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thermionix

^ That might pop while switching, assuming BBM.  I would leave the 47K on the board, and just switch a 10K in parallel.

EBK

You could also use a SPST switch to throw a 10k in parallel with the 47k.  This would let you switch between 47k and 8.25k (the parallel combination). See above.   :icon_wink:
Dang!  Now I know what that feels like!  You beat me to it, thermionix.
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Technical difficulties.  Please stand by.

seagurt

Quote from: vigilante397 on March 02, 2017, 02:48:30 PM


Leave the 47k resistor off of the PCB, solder the two resistors to the switch like this. Now just pretend the two wires from the switch are the two leads of your resistor and solder them into the resistor's pads on the PCB.

Hope this helps ;D

That's exactly what I'm after.

Much obliged.

Quote from: thermionix on March 02, 2017, 03:09:14 PM
^ That might pop while switching, assuming BBM.  I would leave the 47K on the board, and just switch a 10K in parallel.

You lost me at BBM.

If I had the 47k on the board, what points would I be attaching the switch, and the 10k in parallel?
Popping is fine, as I will be using one setting or the other, and not need to change it during a performance.

I am still very new to all of this, and looking for some clarification on these points.

Thanks for all the answers!!
Those who know the least will always know it the loudest.

Long's Law

EBK

Quote from: seagurt on March 02, 2017, 09:20:29 PM

You lost me at BBM.
Me too. 
Bright Bold MOSFETs? 
Bad Bass Modulation?
Big Bloody Mess?
Banjo Banging Monkey? 

Quote
If I had the 47k on the board, what points would I be attaching the switch, and the 10k in parallel?

Imagine 47k resistor on board in normal position.  Now, imagine one end of that resistor is also soldered to an end of a 10k resistor.  You now have the other end of that 10k hanging out unconnected.  Connect it to one terminal of your SPST switch.  The other terminal of your SPST switch goes to the other side of the 47k resistor.  With the switch open, you have 47k in the circuit.  With the switch closed, you have the parallel combination of 47k and 10k, which is 8.25k.
Maybe this makes sense.  A picture would be better....
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Technical difficulties.  Please stand by.

antonis

Quote from: vigilante397 on March 02, 2017, 02:48:30 PM


Leave the 47k resistor off of the PCB, solder the two resistors to the switch like this. Now just pretend the two wires from the switch are the two leads of your resistor and solder them into the resistor's pads on the PCB.
:icon_eek: :icon_eek: How in @^%$$ have you understood what he meant..??  :icon_eek: :icon_eek:

I was sure about one pole of the switch toggle between 2 resistors placed on PCB and the other pole "on air" or for indicator LED..


Probably we drink different kind of coffee...  :icon_biggrin:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

thermionix

BBM=Break Before Make.  A switch that breaks the contact with "A" before making the contact with "B" (not applicable to single throw switches).  It can cause popping in live audio circuits.