USING THE RPS-1in the OM-420
Omega Engineering Inc.
2
Stamford, CT
An integral State-of-Charge (SOC) indicator is provided which will display an approximate Battery State-of-
Charge based on battery voltage under a fixed load. Test is actuated by depressing a momentary SOC
Test Switch.
HARDWARE / USER CONTROLS:
Figure 1 illustrates the functional blocks contained within the RPS-1. An explanation of each block follows:
MAIN POWER SWITCH
Provides ON/OFF control of the RPS-1. In the OFF position, the batteries are disconnected from the RPS-
1 circuits (power supplies, State-of-Charge indicator, charging circuits, etc.). This switch in either 12 VDC
or 24 VDC ON position selects how the two 12 volt gel-cell batteries are connected (parallel for 12 VDC
nominal output or series for 24 VDC nominal output). Note: For charging, the Main Power switch must be in
either the 12VDC or 24VDC position.
CHARGER INPUT
Two terminal connections are provided for connection of an external current source for charging the RPS-1
batteries.
POWER SUPPLY OUTPUTS
Two independent User programmable voltage power supply outputs (A and B) feed the twelve position
terminal strip on the right side of the unit. The top four terminals are all connected to the A supply output
and the middle four to the B supply output. The bottom four terminals are all connected together and to
the COMMON (circuit ground) of the two supplies.
OUTPUT VOLTAGE / MODE SWITCHES
Each of the two power supplies has an eight position DIP switch associated with it. The top seven switches
determine the output voltage for that supply and the last switch (#8) defines the mode of operation (AUTO
or ON) for the power supply.
12 V Gel-Cell
BATTERY
12 V Gel-Cell
BATTERY
Main Power
Switch
Battery State of
Charge light bar
Battery Charging
circuitry
Power Supply
A
Power Supply
B
hl200-01.ecw
External Power
Supply Control
Signal
+
+
-
-
Figure 2: RPS-1 Functional Block Diagram
