Martel Electronics OEM1B-LED - Manual (Page 3)

OEM 1B-LED
3½ Digit LED Voltmeter Module
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PIN FUNCTIONS
1. 0V Negative power supply to the meter.
2. V+ Positive power supply to the meter.
3. IHI Positive measuring input.
IHI must be no closer than 1.5V to either the positive or negative supply (see Note).
4. ILO Negative measuring input.
ILO must be no closer than 1.5V to the positive supply (see Note).
5. COM
6. RLO Negative input for the reference voltage.
7. RHI Positive input for the reference voltage.
8. NC Not connected.
9. DP1 Connect to 0V to display DP1 (199.9).
10. DP2 Connect to 0V to display DP2 (19.99).
11. DP3 Connect to 0V to display DP3 (1.999).
12. TEST Connect to V+ to display all segments, except the decimal points.
Ground for the analogue section of the A/D converter. It is actively held at 3.05V (nom.) below
V+ and must not be allowed to sink excessive current (>100 A) by, for instance, connecting
to a higher voltage.
A negative supply is generated internally and mirrors the positive supply. For example: if V+ is +5V, then
the internally generated V- is -5V. When measuring with the input referenced to the same supply rail as
that of the panel meter, then the limitations on the input range are (V- + 1.5V) to (V+ - 1.5V).
µ
Note:
CIRCUIT DIAGRAM
V+
2
3
4
5
7
6
1
IHI
ILO
COM
RHI
RLO
0V
DP3
DP2
DP1
9
10
11
12
(199.9)
(19.99)
(1.999)
TEST
OEM 1B-LED
3½ Digit LED Voltmeter Module
DISPLAY
CERMET
NC
0
NC
8
PO Box 770, Londonderry, NH 03053 1-800-821-0023
www.martelcorp.com