There are no stupid questions

[Hambo]

Except this one.

Am I right in assuming, that a resistor in parallel with just an unbroken wire or the like, that resistor is essentially bypassed and may as well not exist in the circuit?

In short I'm looking at the Parallel universe starve switch which has the board connected to the middle pole of a SPDT switch going to 9v on one throw, and 9v through a 2.2k resistor on the other. So I think I can do this by connecting the two contacts of a on off toggle switch with the 2.2k resistor and connecting the board and 9v wires to each contact also.

Sorry if thats not very clear, but I have shed load of these switches and no SPDTs...

Thanks

[aron]

>Am I right in assuming, that a resistor in parallel with just an unbroken wire or the like, that resistor is essentially bypassed and may as well not exist in the circuit?

Yes.

[The Tone God]

Lets answer this question with math.

The formula for parallel resistance of two resistors is:

Rtotal = R1 * R2 / R1 + R2

Givens:

R1= 2.2K (Resistor)
R2 = 0 (Jumper)

Work:

Rtotal = 2.2K * 0 / 2.2K + 0

Rtotal = 0 / 2.2K

Rtotal = 0

So yes jumpering a resistor is defeating the value of the resistor.

Andrew

[Mark Hammer]

Not only that, ANY passive component, whether diode, resistor or capacitor, essentially "doesn't exist" when in parallel with a straight wire.

Check it.  If you have an inverting op-amp  (That is, the input goes through a resistor to the "-" pin, and a resistor goes from the output back to that pin), the gain of that op-amp will be the ratio of the feedback resistor to the input resistor.  So, if I have a 100k feedback resistor and a  10k input resistor, that op-amp has a gain of 10.  If I suddenly place a piece of wire in parallel with that 100k resistor, the gain is now...NOTHING....zero....zip....rien....garnicht....nada, because zero divided by 10,000 is still zero.  The PAiA Rocktave uses this trick to leave the buffered clean signal active but shut down the octave.

With noninverting op-amps (and the TS-9 and Distortion+ are examples of this) the gain is set by the ratio of the feedback resistance + ground resistance (the resistance from the "-" pin to ground or Vref) to the ground resistance alone.  A 470k feedback resistance and 4k7 ground resistance yields a gain of [470+4.7]/4.7 = 101.  But if you stick a piece of wire in parallel with that 470k resistor, you get [0+4k7]/4k7 = 1.  That is, any time you short out the feedback path in a noninverting op-amp, it instantly turns into a unity-gain (x1) stage.

This can be used in a myriad of ways.

It's a great question.

[black mariah]

Shorter explanation... electricity follows the path of least resistance. 

[gez]

Fish paste...(there are stupid answers however) 

[Hambo]

Excellent. So I take it my switch will work.

Thanks for the confirmation, I just wanted to double check before I went and put it all together

[kahel]

The subject title is false. Let it be known to the world that there are powerful secret societies devoted to collecting stupid questions. There are streets filled with houses filled with rooms filled with shelves filled with volume upon volume of collected stupid questions. You may recognize members of these societies only by their smug smiles and slick palm recorders. It is their firm belief that when the time comes that genetic engineering has caused the world to be filled with only smart asses, they will own the only source of humor, and thus they'll be able to take over and rule the Earth. Consider yourself warned.

K

[Processaurus]

Its a good question.  I see a lot of peoples switching schemes that can be simplified by shorting out components, like cap switching where you want a big input cap and a little input cap, you can just put both in series and just short out the little one, because that is the bottleneck, not the bigger cap.

Recently I was scratching my head on how to turn on an LED when I disconnected ground from something (footswitch was otherwise full), I finally realized I could just leave the LED cathode connected to ground full time (led on), and then short it out by connecting ground to the anode when I wanted it off.

Likewise anyone doing an LED that blinks to an LFO (like the EA trem), can turn it off when the effect is in bypass by shorting the LED out.

[calculating_infinity]

You know how they say you learn something new everyday...  Well here you learn something new at this forum a few times a each day you read it.  (at least for me)  Thanks for the info!