calibrate mV to V

S

steve

Guest
I have acquired a tiny digital panel meter, but cannot calibrate it.

Although the manual says to change various jumpers (RA, RB, etc.), to
change the mV value into Volts, none of these i.e., RB, RA=100 KΩ,
RB=9.9 MΩ is visible on the board.

But there is a small pot attached at the edge.

So how to achieve the V.

Thanks.

Steve
 
steve wrote:
I have acquired a tiny digital panel meter, but cannot calibrate it.

Although the manual says to change various jumpers (RA, RB, etc.), to
change the mV value into Volts, none of these i.e., RB, RA=100 KΩ,
RB=9.9 MΩ is visible on the board.

But there is a small pot attached at the edge.

So how to achieve the V.

Thanks.

Steve
Click to expand...

Brand? Model?


--
For the last time: I am not a mad scientist! I m just a very ticked
off scientist!!!
 
On Wed, 17 Nov 2010 23:27:30 -0800 (PST), steve
<kvsteve@gmail.com> wrote:

I have acquired a tiny digital panel meter, but cannot calibrate it.

Although the manual says to change various jumpers (RA, RB, etc.), to
change the mV value into Volts, none of these i.e., RB, RA=3D100 K=E2=84=A6=
,
RB=3D9.9 M=E2=84=A6 is visible on the board.

But there is a small pot attached at the edge.

So how to achieve the V.
Click to expand...
I assume that the basic meter itself is set to read mV, and
the jumpers you mention are locations for you to install
resistors to make a voltage divider. If the basic range is
1999 mV (which is 1.999 V), then a divide-by-10 would give
19.99 V, and a divide-by-100 would give 199.9 V.

A divider made from 9.9M and 100K would give a 100:1
reduction. 900K and 100K would give 10:1. The smaller
resistor goes across the present input to the meter, and the
signal is applied through the larger resistor to the "high"
or "positive" side of the meter input. View in Courier or
other fixed-pitch font:

o---9.9M----o----- +
|
100K Meter
|
o-----------o----- -


Best regards,


Bob Masta

DAQARTA v5.10
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
DaqMusic - FREE MUSIC, Forever!
(Some assembly required)
Science (and fun!) with your sound card!
 
On Thu, 18 Nov 2010 14:17:48 GMT, N0Spam@daqarta.com (Bob
Masta) wrote:

On Wed, 17 Nov 2010 23:27:30 -0800 (PST), steve
kvsteve@gmail.com> wrote:

I have acquired a tiny digital panel meter, but cannot calibrate it.

Although the manual says to change various jumpers (RA, RB, etc.), to
change the mV value into Volts, none of these i.e., RB, RA=3D100 K=E2=84=A6=
,
RB=3D9.9 M=E2=84=A6 is visible on the board.

But there is a small pot attached at the edge.

So how to achieve the V.

I assume that the basic meter itself is set to read mV, and
the jumpers you mention are locations for you to install
resistors to make a voltage divider. If the basic range is
1999 mV (which is 1.999 V), then a divide-by-10 would give
19.99 V, and a divide-by-100 would give 199.9 V.

A divider made from 9.9M and 100K would give a 100:1
reduction. 900K and 100K would give 10:1. The smaller
resistor goes across the present input to the meter, and the
signal is applied through the larger resistor to the "high"
or "positive" side of the meter input. View in Courier or
other fixed-pitch font:

o---9.9M----o----- +
|
100K Meter
|
o-----------o----- -
Click to expand...

Oops, forgot to mention that this alone won't move the
decimal point. There should be jumpers for that. Don't
mess with the small pot, since it's probably for base
calibration.

Best regards,


Bob Masta

DAQARTA v5.10
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
DaqMusic - FREE MUSIC, Forever!
(Some assembly required)
Science (and fun!) with your sound card!
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top