Scaling, Applications – Martel Electronics V1 User Manual
Page 4
L1
L1
L1
Specifications liable to change without prior warning
V 1
Issue 3
January/2002
M.C.
Applies to V 1/2
Page 4 of 4
Page 4 of 4
SCALING
Two resistors Ra and Rb
may be used to alter the
full scale reading (FSR) of
the meter - see table. The
meter will have to be re-
calibrated by adjusting the
calibration potentiometer
on the rear of the module.
+
-
Ra
Rb
INHI
Vin or in
I
INLO
FSR
Ra
Rb
2V
910k
100k
20V
1M
10k
Vin
200V
1M
1k
2000V*
1M
100R
200 A
0R
1k
2mA
0R
100R
Iin
20mA
0R
10R
200mA
0R
1R
µ
Voltage
Current
*Ensure that Ra is rated for high voltage use.
APPLICATIONS
Do not connect more than one meter to the same power supply
if the meters cannot use the same signal ground. Taking any
input beyond the power supply rails will damage the meter.
Normally
SHORTED
Cut to
OPEN
Normally
OPEN
Solder to
SHORT
0V
0V
+7.0 to +12V
+7.0 to +12V
+3.5 to +6.0V
-3.5 to -6.0V
V+
V+
V+
IN HI
IN HI
IN HI
IN LO
IN LO
IN LO
1
1
3
3
2
2
V 1
V 1
V 1
V-
V-
V-
4
4
DP1
DP1
XDP
XDP
6
6
5
1
3
2
4
DP1
XDP
6
5
5
±200mV
±200mV
+
+
I+
I-
-
-
Measuring an input voltage referenced to a floating supply,
i.e. the input voltage and the meter's power supply are
isolated from each other. Check Link L1 is closed.
Measuring a single ended input referenced to supply, i.e.
the input voltage and the meter's power supply share the
same 0V rail. Check Link L1 is open.
Measuring a current referenced to a floating supply, i.e. the
current being measured and the meter's power supply are
isolated from each other. Check Link L1 is closed.
V 1
3½ Digit LCD Voltmeter Module
www.lascarelectronics.com
www.martelmeters.com
page 4 of 4