A bit of clarification

[John Egerton]

Hi... I know I've asked this question before but I'd just like to be reassured about this...



That is a diagram of a circuit....

I want it wired like it is, however the resistor touchpad has an unknown resistance above 5k.

I would like to know how to limit the maximum resistance of the pad to 5k without affecting the other pot.

Bear in mind that when the touchpad is not pressed th connection is completley severed.

Thanks guys...

John

[Jason Stout]

The resistance of the touchpad/pot combo will be less than 5k. Your circuit limits resistance to no more than 5kΩ.

Keep in mind, if the "touch pad" is of lesser resistance than the pot, then it (the touch pad) is the limiting factor in all this.

[John Egerton]

If the pot is turned all the way so that it is off... will the maximum resistance of the touchpad still be 5k?

The resistance of thetouchpad on its own is more than 5k

[Jason Stout]

If the pot is turned all the way so that it is off... will the maximum resistance of the touchpad still be 5k?

The resistance of thetouchpad on its own is more than 5k

If "all the way off" is 0Ω then the equivalent resistance of the resistive strip and pot is also 0Ω, if "all the way off" is 5kΩ then the maximum equivalent resistance of the combo is ~5kΩ if and only if the resistance of the strip is greater than 5kΩ.

[Jason Stout]

Check out this site:
http://www.doctronics.co.uk/resistor.htm

[Fp-www.Tonepad.com]

Simple way to put it:

The total resistance of two resistors in parallel will always be lower than the value of the resistor that has the lowest value.


Fp

[Thomas P.]

As Fp said parallel resistors add up their inverse. Means 1/R = 1/r1 + 1/r2 +....
With two resistors you can  say: R = (r1 * r2)/(r1 + r2)