Variable resistance

[prprog]

Is there a single component that will vary its resistance value (lets say from 0 - 100kohms) when a voltage is apply to it? Thank.

 

[Nigel Goodwin]

Not really I'm afraid, and particularly not without complete details of what it's going to be used for.

 

[prprog]

Additional Information

The idea is to controlled an audio source with a variable pot (for volume control) . The control voltage is in the +5v range (from 0). Is there any component that by receiving from 0 to +5v (or less) can varied its resistance and control an audio source?

 

[dknguyen]

A JFET does I think. But they are not sold "ready" for this and you will have to characterize it.

**broken link removed**

 

[on1aag]

Hi Prprog,

There is such a "thing", it's called a digitally controlled potentiometer.
It's not controlled by a voltage but it's relatively easy to use.
Xicor used to produce them, now they are available from Intersil.

https://www.electro-tech-online.com/custompdfs/2008/03/FN8185.pdf

You could give that chip a clock signal, say 20 Hz or so, and control
it with a 3 position DPDT switch. Up / 0 / Down
One switch is for the chip enable and the other switch is for up or down.

on1aag.

 

[audioguru]

There are ICs that are controlled by variable DC voltages from pots that have stereo volume, bass, treble and balance.

 

[jpanhalt]

Dallas (Maxim) makes another digital pot that can be controlled with a simple SPDT switch or two button switches (e.g., up, down). No clock is needed.

https://pdf1.alldatasheet.com/datasheet-pdf/view/58556/DALLAS/DS1869.html

John

 

[ronsimpson]

Thatcorp.com makes many voltage controlled amplifier for audio use.
National.com makes some, like the CLC520. (very fast)
Ti.com VCA610.
Coolaudio.com V2159
Analog devices SSM2022 & SSM2164
Also research “four quadrant multiplier” MC1494