Martel Electronics SP400 - Manual (Page 4)

SP 400
3½ Digit Backlit LCD Voltmeter Module
Specifications liable to change without prior warning SP 400 Issue 6 June/2002 M.C. Applies to SP 400/3
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.
5V supply operation
(3.0 to 7.5V Meter Power Supply)
9V supply operation
(6.0 to 15.0V Meter Power Supply)
SCALING
Two external 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.
FSR Ra Rb
2V 910k 100k
20V 1M 10k
200V 1M 1k
2000V* 1M 100R
200 A 0R 1k
2mA 0R 100R
20mA 0R 10R
200mA 0R 1R
µ
Voltage
Current
+
-
Ra
Rb
INH
4
5
Vin or in I
INL
SP 400
Page 4 of 4
*Ensure that Ra is rated for high voltage use.
+3.0 to +7.5V
+3.0 to +7.5V
-3.0 to -7.5V
+3.0 to +7.5V
+6.0 to +15.0V
+3.0 to +7.5V
+6.0 to +15.0V
V+
V+
INH
INH
INL
INL
0V
GND
V-
+
+
-
-
±200mV
±200mV
Measuring a single ended input
voltage referenced to supply, i.e. the
input voltage and the meter's power
supply share the same 0V rail.
Ensure solder link LCOM is open.
Measuring a single ended input
voltage referenced to supply, i.e. the
input voltage and the meter's power
supply share the same 0V rail.
Ensure solder link LCOM is open.
V+
V+
V+
V+
INH
INH
INH
INH
INL
INL
INL
INL
0V
0V
GND
V-
GND
V-
+
+
-
-
±200mV
±200mV
Measuring a current from a circuit which is
floating with respect to the DPM's supply,
i.e. the current and the meter's power
supply are isolated from each other.
Ensure solder link LCOM is closed.
Measuring a current from a circuit which is
floating with respect to the DPM's supply,
i.e. the current and the meter's power
supply are isolated from each other.
Ensure solder link LCOM is closed.
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.
Ensure solder link LCOM is closed.
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.
Ensure solder link LCOM is closed.
Rb
Rb
I +
I +
I-
I-
www.lascarelectronics.com
1
2
4
5
1
9
4
5
1
9
4
5
1
9
4
5
1
2
4
5
1
2
4
5
6
8
7
DP1
No DP
DP2
DP3
3
0V
BL-
if V+>5V then
Rs=(V+ - 5V)
0.04
3
0V
BL-
Rs=(V+ - 5V)
0.04
3
BL-
Rs=(V+) - (V-) - 5V
0.04
PO Box 770, Londonderry, NH 03053 1-800-821-0023
www.martelcorp.com