Martel Electronics EM32-1B-LED - Manual (Page 3)

EM32-1B-LED Martel Electronics Corporation 3
CIRCUIT DIAGRAM
EM32-1B-LED
Round Hole Mounting LED Voltmeter
J1
J2
DISPLAY
0V
ILO
IHI
V+
MAX140
CAP-
GND
CAP+ C6
1u5 C6
1u5
R6
1k0
R5
3k0
R4
100k
R7
1k5
ANODE
DP1, DP2, DP3
DGND
21
Ra
Rb
Page 4 of 4
SCREW TERMINAL FUNCTIONS
JUMPER LINKS
0V Negative power supply to the meter.
V+ Positive power supply to the meter (+5V nom).
IHI Positive measuring input.
IHI must be no closer than 1.5V to either the positive or the internal negative supply.
ILO Negative measuring input.
ILO must be no closer than 1.5V to either the positive or the internal negative supply.
Internal negative supply. This is generated from the supply voltage between V+ and 0V, and is negative
with respect to 0V.
For example:
if V+ = +5V (with respect to 0V), then the allowable common mode input range is from
(V+ - 1.5V) to (V- + 1.5V) or from 3.5V to -3.5V with respect to the 0V power supply connection.
J1 Connects ILO to COM, when jumper link is fitted.
J2 Connects ILO to 0V, when jumper link is fitted.
Note:
Page 4 of 4