Martel Electronics OEM1B - Manual (Page 3)

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OEM 1B
3½ Digit LCD Voltmeter Module
CIRCUIT DIAGRAM
PIN FUNCTIONS
1. V- 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 1.6V to either the positive or negative supply, when using the
internal 100mV reference.
4. ILO Negative measuring input.
ILO must be no closer than 1.6V to either the positive or negative supply, when using the
internal 100mV reference.
5. COM
6. RLO Negative input for the reference voltage.
7. RHI Positive input for the reference voltage.
8. NC Do not connect.
9. DP1 Connect to XDP to display DP1 (199.9).
10. DP2 Connect to XDP to display DP2 (19.99).
11. DP3 Connect to XDP to display DP3 (1.999).
12. XDP Connect to DP1, DP2 or DP3 to display required 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 (>100mA) by, for instance, connecting
to a higher voltage.
www.lascarelectronics.com
NC
PO Box 770, Londonderry, NH 03053 1-800-821-0023
www.martelcorp.com
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