Using a Panel Meter movement

P

Patrick Keenan

Guest
Hello All,

I'm trying to sort out how to use an analog, needle-style, coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring to:
http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcentric_Taut_Band.html

So I'm looking for a sample circuit that shows me how this sort of movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have. I'm finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan
 
<extremesoundandlight@yahoo.com> wrote in message
news:2f70ab98-4775-4ec0-b544-b929c35fca58@x16g2000prn.googlegroups.com...
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:
Hello All,

I'm trying to sort out how to use an analog, needle-style, coild&spring
type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring
to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...

So I'm looking for a sample circuit that shows me how this sort of
movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have. I'm finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is above
or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan
Click to expand...
use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure

=====
Thanks for the reply. For application, think "guitar tuner". What is
being measured is an incoming frequency, relative to a specific reference,
so the needle rests in the middle and moves right or left. There's a
microcontroller involved, so I assume that I'll be converting that incoming
frequency to a voltage to run the meter itself. The meter won't be the
only display, but I find that for me, the needle movement is the best visual
cue.

Do you know of any sample circuits so I can see what sorts of voltages and
currents are normally acceptable for this kind of movement, and how they are
normally connected? Or a sample datasheet? These seem harder to find
than I expected.

Thanks again,
Patrick Keenan
 
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:
Hello All,

I'm trying to sort out how to use an analog, needle-style, coild&spring type
of panel meter movement.   I have a couple of samples to play with,
unfortunately I have no infomation about them.   On one, the needle rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...

So I'm looking for a sample circuit that shows me how this sort of movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have.   I'm finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan
Click to expand...
use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure
 
Patrick Keenan wrote:
extremesoundandlight@yahoo.com> wrote in message
news:2f70ab98-4775-4ec0-b544-b929c35fca58@x16g2000prn.googlegroups.com...
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:
Hello All,

I'm trying to sort out how to use an analog, needle-style,
coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle
rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring
to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...


So I'm looking for a sample circuit that shows me how this sort of
movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have. I'm
finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is
above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan

use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure

=====
Thanks for the reply. For application, think "guitar tuner".
What is being measured is an incoming frequency, relative to a specific
reference, so the needle rests in the middle and moves right or left.
There's a microcontroller involved, so I assume that I'll be converting
that incoming frequency to a voltage to run the meter itself. The
meter won't be the only display, but I find that for me, the needle
movement is the best visual cue.

Do you know of any sample circuits so I can see what sorts of voltages
and currents are normally acceptable for this kind of movement, and how
they are normally connected? Or a sample datasheet? These seem
harder to find than I expected.
Click to expand...
Select the right value of R for the circuit below (R = VCC/(2*Imax),
with Imax being the meter's maximum current). It'll give your two-way
meter just the motion you want. For a one-way meter use R = VCC/Imax.

VCC
+
|
|
.-.
| |
| | R
'-'
_ |
Vin / \ |
o--------(_/_)-----o
\_/ |
|
.-.
| |
| | R
'-'
|
|
===
GND
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

DC current meter movements vary widely in sensitivity. Usually the
cheap ones are 1mA full scale, 'normal' spendy ones are 50uA full scale,
and if you have a really interesting antique it could be anything. So
you'll have to measure it, and you'll want to start with a source
that'll deliver 50uA or less -- a 200k-ohm resistor and a 9V battery
will give you about 45uA if my in-the-head calculation is right. Once
you see what the reading is at 45uA you can adjust your resistor
accordingly to get a good reading.

There's no guarantee that what you have is a DC current meter. You may
have an AC current (or voltage) meter, or a DC voltage meter. Without
specifications, you'll have to check to see. The most common
possibility is a DC current meter, because that's the easiest accurate
meter to make.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
On Mon, 15 Sep 2008 10:43:28 -0400, "Patrick Keenan" <test@dev.null>
wrote:

Hello All,

I'm trying to sort out how to use an analog, needle-style, coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring to:
http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcentric_Taut_Band.html

So I'm looking for a sample circuit that shows me how this sort of movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have.
Click to expand...
---
A taut-band meter movement is a variation of a d'Arsonval movement, the
difference being that the taut-band movement has no hairsprings, pivots,
or jewels.

In use, a bobbin around which a coil of magnet wire has been wound and
to which a pointer is affixed is suspended in a permanent magnetic field
such that when charge flows through the coil the bobbin is caused to
rotate until the torque exerted by the taut band becomes equal and
opposite to the sign of the torque being generated by the current in the
coil and the PM field.
---



I'm finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan
JF
Click to expand...
 
"Tim Wescott" <tim@seemywebsite.com> wrote in message
news:RaKdnRohAZFaAVPVnZ2dnUVZ_gOdnZ2d@web-ster.com...
Patrick Keenan wrote:

extremesoundandlight@yahoo.com> wrote in message
news:2f70ab98-4775-4ec0-b544-b929c35fca58@x16g2000prn.googlegroups.com...
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:
Hello All,

I'm trying to sort out how to use an analog, needle-style, coild&spring
type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle rests
on
the left, on the other, the in the center - this is actually the one I
am
most interested in using.

For clairty this is the kind of device I'm referring
to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...

So I'm looking for a sample circuit that shows me how this sort of
movement
is connected and driven, or just what words to use on Google to find
such
circuits, and how to figure out details on the samples I have. I'm
finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is above
or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan

use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure

=====
Thanks for the reply. For application, think "guitar tuner". What
is being measured is an incoming frequency, relative to a specific
reference, so the needle rests in the middle and moves right or left.
There's a microcontroller involved, so I assume that I'll be converting
that incoming frequency to a voltage to run the meter itself. The meter
won't be the only display, but I find that for me, the needle movement is
the best visual cue.

Do you know of any sample circuits so I can see what sorts of voltages
and currents are normally acceptable for this kind of movement, and how
they are normally connected? Or a sample datasheet? These seem
harder to find than I expected.


Select the right value of R for the circuit below (R = VCC/(2*Imax), with
Imax being the meter's maximum current). It'll give your two-way meter
just the motion you want. For a one-way meter use R = VCC/Imax.

VCC
+
|
|
.-.
| |
| | R
'-'
_ |
Vin / \ |
o--------(_/_)-----o
\_/ |
|
.-.
| |
| | R
'-'
|
|
===
GND
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

DC current meter movements vary widely in sensitivity. Usually the cheap
ones are 1mA full scale, 'normal' spendy ones are 50uA full scale, and if
you have a really interesting antique it could be anything. So you'll
have to measure it, and you'll want to start with a source that'll deliver
50uA or less -- a 200k-ohm resistor and a 9V battery will give you about
45uA if my in-the-head calculation is right. Once you see what the
reading is at 45uA you can adjust your resistor accordingly to get a good
reading.

There's no guarantee that what you have is a DC current meter. You may
have an AC current (or voltage) meter, or a DC voltage meter. Without
specifications, you'll have to check to see. The most common possibility
is a DC current meter, because that's the easiest accurate meter to make.
Click to expand...

Thanks to all. These are the kinds of clues I needed.

Patrick Keenan

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
Click to expand...
 
On Mon, 15 Sep 2008 10:43:28 -0400, Patrick Keenan wrote:

Hello All,

I'm trying to sort out how to use an analog, needle-style, coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring to:
http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcentric_Taut_Band.html
Click to expand...
The web site says they have "100 ľA" movements - that's probably 0-100FS
for one, and 50-0-50 for the other.

So, take a 1.5V battery, a 10K pot, and a resistor of (1.5V/100 ľA) ohms;

wire them like this:

+-----+
| |
- |
1.5V _ [10K]<----[15K]----+
| | |
| | [meter]
| | |
+-----+----------------+

That should give you zero to full-scale deflection. The 15K resistor
will turn a 100ľA meter into a 0-1.5 voltmeter. Reverse the leads for
negtive deflection (like to test the 50-0-50 meter.)

Start the 10K pot at the low end (i.e., 0 volts) and crank it up
slowly, to make sure you have the polarity right and that I've guessed
right on the 15K value. ;-)

IOW, check my math! ;-)

Have Fun!
Rich
 
Patrick Keenan wrote:
extremesoundandlight@yahoo.com> wrote in message
news:2f70ab98-4775-4ec0-b544-b929c35fca58@x16g2000prn.googlegroups.com...
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:

Hello All,

I'm trying to sort out how to use an analog, needle-style,
coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle
rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring
to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...


So I'm looking for a sample circuit that shows me how this sort of
movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have. I'm
finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is
above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan


use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure

=====
Thanks for the reply. For application, think "guitar tuner".
What is being measured is an incoming frequency, relative to a specific
reference, so the needle rests in the middle and moves right or left.
There's a microcontroller involved, so I assume that I'll be converting
that incoming frequency to a voltage to run the meter itself. The
meter won't be the only display, but I find that for me, the needle
movement is the best visual cue.

Do you know of any sample circuits so I can see what sorts of voltages
and currents are normally acceptable for this kind of movement, and how
they are normally connected? Or a sample datasheet? These seem
harder to find than I expected.

Thanks again,
Patrick Keenan
Click to expand...
The meter is driven by current. The voltage level powering
a microprocessor will be fine, but the current *must* be
limited to less than 100 ua, per the page you posted.

Assuming a 5 volt supply, you can use a 2 meg resistor in
series to limit the current to no more than 50 uA to give
yourself a wide safety margin when testing the meter.

Your actual circuit will dictate how the thing is wired when
in use, but in general it will have a fixed and a variable
resistance in series. The variable resistance is used to
calibrate the full scale meter reading. Something like this:

R1 VR1
+---/\/\/\----/\/\/\
| ^
| |
[Source] [Meter]
| |
+----------------+

Source in the diagram is whatever circuit element drives the
meter - transistor, op amp, uprocessor, whatever.

Ed
 
On Sep 15, 12:37 pm, ehsjr <eh...@NOSPAMverizon.net> wrote:
Patrick Keenan wrote:

extremesoundandli...@yahoo.com> wrote in message
news:2f70ab98-4775-4ec0-b544-b929c35fca58@x16g2000prn.googlegroups.com....
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:

Hello All,

I'm trying to sort out how to use an analog, needle-style,
coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle
rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring
to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...

So I'm looking for a sample circuit that shows me how this sort of
movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have. I'm
finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is
above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan

use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure

====> > Thanks for the reply.   For application, think "guitar tuner".      
What is being measured is an incoming frequency,  relative to a specific
reference, so the needle rests in the middle and moves right or left.  
There's a microcontroller involved, so I assume that I'll be converting
that incoming frequency to a voltage to run the meter itself.   The
meter won't be the only display, but I find that for me, the needle
movement is the best visual cue.

Do you know of any sample circuits so I can see what sorts of voltages
and currents are normally acceptable for this kind of movement, and how
they are normally connected?   Or a sample datasheet?     These seem
harder to find than I expected.

Thanks again,
Patrick Keenan

The meter is driven by current. The voltage level powering
a microprocessor will be fine, but the current *must* be
limited to less than 100 ua, per the page you posted.

Assuming a 5 volt supply, you can use a 2 meg resistor in
series to limit the current to no more than 50 uA to give
yourself a wide safety margin when testing the meter.

Your actual circuit will dictate how the thing is wired when
in use, but in general it will have a fixed and a variable
resistance in series. The variable resistance is used to
calibrate the full scale meter reading. Something like this:

          R1        VR1
    +---/\/\/\----/\/\/\
    |                ^
    |                |
[Source]         [Meter]
    |                |
    +----------------+

Source in the diagram is whatever circuit element drives the
meter - transistor, op amp, uprocessor, whatever.

Ed- Hide quoted text -

- Show quoted text -
Click to expand...

how about I just give you guitar tuner schematic so the resisters are
already set for your frequency dividing network to match A B C D E F
and G would that be better for you the VU meter just measures the
voltage difference a good one measures variance in current and
Voltage.
 
Phil Allison wrote:
"ehsjr"


The meter is driven by current. The voltage level powering
a microprocessor will be fine, but the current *must* be
limited to less than 100 ua, per the page you posted.

Assuming a 5 volt supply, you can use a 2 meg resistor in
series to limit the current to no more than 50 uA to give
yourself a wide safety margin when testing the meter.


** Huh ???

100k is the value needed.



...... Phil

Perhaps that's in case the 5 volt supply should suddenly spike to 40V?
Click to expand...

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
<extremesoundandlight@yahoo.com> wrote in message
news:933694b4-c61d-4db7-8236-b1168e5c0ce8@v13g2000pro.googlegroups.com...
On Sep 15, 12:37 pm, ehsjr <eh...@NOSPAMverizon.net> wrote:
Patrick Keenan wrote:

extremesoundandli...@yahoo.com> wrote in message
news:2f70ab98-4775-4ec0-b544-b929c35fca58@x16g2000prn.googlegroups.com...
On Sep 15, 7:43 am, "Patrick Keenan" <t...@dev.null> wrote:

Hello All,

I'm trying to sort out how to use an analog, needle-style,
coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle
rests on
the left, on the other, the in the center - this is actually the one I
am
most interested in using.

For clairty this is the kind of device I'm referring
to:http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcent...

So I'm looking for a sample circuit that shows me how this sort of
movement
is connected and driven, or just what words to use on Google to find
such
circuits, and how to figure out details on the samples I have. I'm
finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is
above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.

Thanks!
Patrick Keenan

use a meter whith known values in a circiut to set your full scale
deflection on your VU meter for what your going to measure

what the application.
what are you tring to measure

=====
Thanks for the reply. For application, think "guitar tuner".
What is being measured is an incoming frequency, relative to a specific
reference, so the needle rests in the middle and moves right or left.
There's a microcontroller involved, so I assume that I'll be converting
that incoming frequency to a voltage to run the meter itself. The
meter won't be the only display, but I find that for me, the needle
movement is the best visual cue.

Do you know of any sample circuits so I can see what sorts of voltages
and currents are normally acceptable for this kind of movement, and how
they are normally connected? Or a sample datasheet? These seem
harder to find than I expected.

Thanks again,
Patrick Keenan

The meter is driven by current. The voltage level powering
a microprocessor will be fine, but the current *must* be
limited to less than 100 ua, per the page you posted.

Assuming a 5 volt supply, you can use a 2 meg resistor in
series to limit the current to no more than 50 uA to give
yourself a wide safety margin when testing the meter.

Your actual circuit will dictate how the thing is wired when
in use, but in general it will have a fixed and a variable
resistance in series. The variable resistance is used to
calibrate the full scale meter reading. Something like this:

R1 VR1
+---/\/\/\----/\/\/\
| ^
| |
[Source] [Meter]
| |
+----------------+

Source in the diagram is whatever circuit element drives the
meter - transistor, op amp, uprocessor, whatever.

Ed- Hide quoted text -

- Show quoted text -
Click to expand...

how about I just give you guitar tuner schematic so the resisters are
already set for your frequency dividing network to match A B C D E F
and G would that be better for you the VU meter just measures the
voltage difference a good one measures variance in current and
Voltage.
======

Thanks for the kind offer, but I'm actually doing this for another reason.
And the meter is just one of the visual indicators that will be included;
the rest I understand but this part I've never used before.

Thanks again.
Patrick Keenan
 
On Mon, 15 Sep 2008 10:43:28 -0400, "Patrick Keenan" <test@dev.null>
wrote:

I'm trying to sort out how to use an analog, needle-style, coild&spring type
of panel meter movement. I have a couple of samples to play with,
unfortunately I have no infomation about them. On one, the needle rests on
the left, on the other, the in the center - this is actually the one I am
most interested in using.

For clairty this is the kind of device I'm referring to:
http://www.process-controls.com/Modtronics/Beede_panel_meters_Magcentric_Taut_Band.html

So I'm looking for a sample circuit that shows me how this sort of movement
is connected and driven, or just what words to use on Google to find such
circuits, and how to figure out details on the samples I have. I'm finding
lots of results on meters except for how to do this.

I'm intending to use this movement to indicate whether a signal is above or
below a given value - if you think of a guitar tuner, that's probably a
helpful example.
Click to expand...


Hello Patrick,

I have a software solution that approaches the idea of what you are
doing. I use this for rapid theremin musical note display. It shows
the +/- deviation of the displayed note, frequency and wave shape.

http://www.oldtemecula.com/theremin/ult_antenna/pitchtuner.htm

* * * *

Christopher

Temecula CA.USA
http://www.oldtemecula.com
 
Phil Allison wrote:
"ehsjr"



The meter is driven by current. The voltage level powering
a microprocessor will be fine, but the current *must* be
limited to less than 100 ua, per the page you posted.

Assuming a 5 volt supply, you can use a 2 meg resistor in
series to limit the current to no more than 50 uA to give
yourself a wide safety margin when testing the meter.



** Huh ???

100k is the value needed.
Click to expand...

Thanks! You are correct, of course. My error.

Ed

...... Phil
Click to expand...
 
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