hooking up a potentiometer
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In a Basic Stamp breadboard project I'm building one of the parts used is a
manual potentiometer. This part has three pins in a "triangle"
configuration and I'm confused as to how to wire it up. Are potentiometers
the same as resistors in that the connected direction is irrelevant or do
each of the pins have a specific connection requirement like an IC?
Thanks,
/* Andrew */
Software Engineer
BSQUARE Corporation
email: andrewt@b...
phone: 425-519-6103
homepage: http://www.halcyon.com/ast
manual potentiometer. This part has three pins in a "triangle"
configuration and I'm confused as to how to wire it up. Are potentiometers
the same as resistors in that the connected direction is irrelevant or do
each of the pins have a specific connection requirement like an IC?
Thanks,
/* Andrew */
Software Engineer
BSQUARE Corporation
email: andrewt@b...
phone: 425-519-6103
homepage: http://www.halcyon.com/ast
Comments
resistance. A 10K pot, for example, should read 10K between those two pins.
The middle pin will be the wiper and will change as the knob changes. The
difference between the ends will be the amount of resistance. For example,
say you twist the knob to 25% of full scale. The R between the center and
one pin will be 25% FS and the other pin will read 75% of full scale. So how
you wire it can influence what "up" and "down" looks like. Usually you want
clockwise motion to be "up" but that doesn't always mean more resistance. To
turn up volume, you might decrease resistance.
You often see one side shorted to the wiper. That's ok because it just
shorts out the part you aren't using. This makes the 3 terminal poteniometer
into a 2 terminal device that has varying resistance.
Hook and ohmmeter up to your pot and you'll quickly see what I'm saying.
On the subject, some pots are linear (sort of). That means that 25% turn of
the knob should get you about 25% of the R and 75% should get you 75%.
Others are "audio taper". That's because your ears are not linear. If you
made a linear volume control you'd find most of the useful volume bunched up
at one end. An audio taper pot has a log response that more closely matches
a normal ear's response.
Not sure if that pegged your question or not.
Regards,
Al Williams
AWC
* Stamp project of the month: http://www.al-williams.com/awce
BSquare... the Windows CE guys, right?
>
Original Message
> From: Andrew Tucker [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rh3xa9_Syw5i1dOXZBkPjM9eRLuzcubJaeBNvl8wZr7Sh7kgbyumQVJIUXEUKl2Ibz2dcZsVmHOH6E-xPPE]AndrewT@b...[/url
> Sent: Monday, April 03, 2000 12:43 PM
> To: 'basicstamps@egroups.com'
> Subject: [noparse][[/noparse]basicstamps] hooking up a potentiometer
>
>
>
> In a Basic Stamp breadboard project I'm building one of the parts
> used is a
> manual potentiometer. This part has three pins in a "triangle"
> configuration and I'm confused as to how to wire it up. Are
> potentiometers
> the same as resistors in that the connected direction is irrelevant or do
> each of the pins have a specific connection requirement like an IC?
>
> Thanks,
>
>
> /* Andrew */
> Software Engineer
> BSQUARE Corporation
> email: andrewt@b...
> phone: 425-519-6103
> homepage: http://www.halcyon.com/ast
>
>
>
The 2 outside pins are the ends of the actual resistor, the middle pin will
be what is called a wiper. depending on which way you connect the 2 outside
pins, will determine in which direction the resistance either increases or
decreases at the middle or wiper pin.
Hope this helps, let me know if you need any further info. I could draw a
simple schematic and send it to you.
Randy A.
cnc002@a...
>
>In a Basic Stamp breadboard project I'm building one of the parts used is a
>manual potentiometer. This part has three pins in a "triangle"
>configuration and I'm confused as to how to wire it up.
Where did the part come from - manufacturer and part number ?
Are potentiometers
>the same as resistors in that the connected direction is irrelevant or do
>each of the pins have a specific connection requirement like an IC?
>
>Thanks,
>
>
>/* Andrew */
>Software Engineer
>BSQUARE Corporation
>email: andrewt@b...
>phone: 425-519-6103
>homepage: http://www.halcyon.com/ast
>
>
>
>
>
center pin common for both. You have a 10k limit. When one resistor goes up,
the other goes down. Get it?
-William
Original Message
From: Andrew Tucker <AndrewT@b...>
To: <basicstamps@egroups.com>
Sent: Monday, April 03, 2000 1:43 PM
Subject: [noparse][[/noparse]basicstamps] hooking up a potentiometer
>
> In a Basic Stamp breadboard project I'm building one of the parts used is
a
> manual potentiometer. This part has three pins in a "triangle"
> configuration and I'm confused as to how to wire it up. Are
potentiometers
> the same as resistors in that the connected direction is irrelevant or do
> each of the pins have a specific connection requirement like an IC?
>
> Thanks,
>
>
> /* Andrew */
> Software Engineer
> BSQUARE Corporation
> email: andrewt@b...
> phone: 425-519-6103
> homepage: http://www.halcyon.com/ast
>
>
>
>
>