lizardbo... at (no spam) gmail.com wrote:

I would like to convert some output (ohm resistance?) from a
potentiometer to an on/off switch.

My electronics experience extends to being able to solder stuff...but
that's pretty much it.  I take stuff apart, sometimes it goes back
together (and works).

I have a 3 axis joystick that operates by using potentiometers.  The
output I can measure on them is from about 10 ohms (centered) to about
6 ohms at the 100% extended point.  At the 50% extended point, I'd
like the switch to be "on".

Are the 3 pots totally separate, or are they
interconnected in any way? Do you have all 3
terminals of each pot available, or does each
only have 2?

These details will determine the kinds of
circuits we can recommend.

lizardbo... at (no spam) gmail.com wrote:
I would like to convert some output (ohm resistance?) from a
potentiometer to an on/off switch.

My electronics experience extends to being able to solder stuff...but
that's pretty much it.  I take stuff apart, sometimes it goes back
together (and works).

I have a 3 axis joystick that operates by using potentiometers.  The
output I can measure on them is from about 10 ohms (centered) to about
6 ohms at the 100% extended point.  At the 50% extended point, I'd
like the switch to be "on".

I'm guessing (this really is a guess) that I need a relay of some
sort...but I don't even know what to ask for or look for.  For all I
know, you can do something with some resistors...or there's some
premade gadget that just does what I want to do.

Any tips, knowledge, even circuit diagrams that I could decipher would
be appreciated.

You need a voltage comparator.

http://www.allaboutcircuits.com/vol_6/chpt_6/2.html

  The circuit shown here will only drive a circuit of
low current when on like around 10 ma's or so. if you
need more, you can use a transistor to boost current.
  check back with the guys on that later on also, you can
use an alternate part like a LM311 which can drive a small
relay coil.
 http://www.fairchildsemi.com/ds/LM/LM311.pdf

on this, you would need to connect the COM and VEE together
when using a single ended supply. also, the output only sinks
which means it pulls to common and does not source an output
equal or near the power supply voltage.. This isn't a problem because
you can thus pull AUX control line functions to common that have higher
voltages than what this chip uses. For example, you can operate the
chip at 5 volts and pull a load to common up to 40 volts..
   This is more favorable when signaling various AUX equipment.

You may want recheck the values on the pots, those sizes sounds a bit
on the low side..
   Are you sure there isn't a "K" on the display on your meter?
this would make more sense..
   the readings you would be getting would then be 10K ohms and 6 K
ohms.
  etc..

http://webpages.charter.net/jamie_5"

I would like to convert some output (ohm resistance?) from a
potentiometer to an on/off switch.

My electronics experience extends to being able to solder stuff...but
that's pretty much it. I take stuff apart, sometimes it goes back
together (and works).

I have a 3 axis joystick that operates by using potentiometers. The
output I can measure on them is from about 10 ohms (centered) to about
6 ohms at the 100% extended point. At the 50% extended point, I'd
like the switch to be "on".

I'm guessing (this really is a guess) that I need a relay of some
sort...but I don't even know what to ask for or look for. For all I
know, you can do something with some resistors...or there's some
premade gadget that just does what I want to do.

Any tips, knowledge, even circuit diagrams that I could decipher would
be appreciated.
You need a voltage comparator.

I would like to convert some output (ohm resistance?) from a
potentiometer to an on/off switch.

My electronics experience extends to being able to solder stuff...but
that's pretty much it. I take stuff apart, sometimes it goes back
together (and works).

I have a 3 axis joystick that operates by using potentiometers. The
output I can measure on them is from about 10 ohms (centered) to about
6 ohms at the 100% extended point. At the 50% extended point, I'd
like the switch to be "on".

Thanks for the responses. Voltage Comparitor sounds kind of like
something Marty and the Doc would use on their time machine.

I *think* I understand the concept...I'm comparing the pot to some
voltage that I want, and when it hits the right voltage, the switch is
open (in the example, lighting up the little light).

The readings are indeed 10k and 6k ohms, not 10 and 6 as I stated
earlier. The meter was on the "x1k" setting.

There are 3 separate pots. Each has 3 leads.

The motion of each pot
when moving the joystick in the 3 directions does not fully extend the
pots from full open to full close.

On May 29, 7:09 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l... at (no spam) charter.net> wrote:

lizardbo... at (no spam) gmail.com wrote:

I would like to convert some output (ohm resistance?) from a
potentiometer to an on/off switch.

My electronics experience extends to being able to solder stuff...but
that's pretty much it. I take stuff apart, sometimes it goes back
together (and works).

I have a 3 axis joystick that operates by using potentiometers. The
output I can measure on them is from about 10 ohms (centered) to about
6 ohms at the 100% extended point. At the 50% extended point, I'd
like the switch to be "on".

I'm guessing (this really is a guess) that I need a relay of some
sort...but I don't even know what to ask for or look for. For all I
know, you can do something with some resistors...or there's some
premade gadget that just does what I want to do.

Any tips, knowledge, even circuit diagrams that I could decipher would
be appreciated.

You need a voltage comparator.

http://www.allaboutcircuits.com/vol_6/chpt_6/2.html

The circuit shown here will only drive a circuit of
low current when on like around 10 ma's or so. if you
need more, you can use a transistor to boost current.
check back with the guys on that later on also, you can
use an alternate part like a LM311 which can drive a small
relay coil.
http://www.fairchildsemi.com/ds/LM/LM311.pdf

on this, you would need to connect the COM and VEE together
when using a single ended supply. also, the output only sinks
which means it pulls to common and does not source an output
equal or near the power supply voltage.. This isn't a problem because
you can thus pull AUX control line functions to common that have higher
voltages than what this chip uses. For example, you can operate the
chip at 5 volts and pull a load to common up to 40 volts..
This is more favorable when signaling various AUX equipment.

You may want recheck the values on the pots, those sizes sounds a bit
on the low side..
Are you sure there isn't a "K" on the display on your meter?
this would make more sense..
the readings you would be getting would then be 10K ohms and 6 K
ohms.
etc..

http://webpages.charter.net/jamie_5"


Again, thx for the help. I've already learned more than I knew
before.

I need to add that each pot actually represents an Axis, so there is a
positive switch point and a negative switch point. Don't know if this
makes a difference...I'm sure it does.

In the example you linked to, on the final diagram...the pot I want to
compare (joystick axis) would go in place of the Windmill. Could I
replace the pot in that last diagram with a 6k ohm resistor since this
is the tipping point?
Well, that's actually a generator but I understand what you're talking