Badger Meter Converters - Manual (Page 7)

Loop Resistance
200
400
600
800
1000
1200
1400
10 12 14 16 18 20 22 24
Supply Voltage (VDC)
Loop Load (Ohm's)
Operate in the
Shaded Region
26 28 30
p
Figure 3: Loop resistance chart
Power Supply Calculations
Example 1
F
to
I
Converter
24V DC
Power
Supply
4…20 mA
150
Ohms
100
Ohms
50
Ohms
Figure 4: Power supply calculation example 1
Known values are:
Total Load Resistance = 300 Ω
Power Supply = 24V DC
At 20 mA loop current, the voltage drop across the load(s) is:
300 Ω x 20 mA = 6000 mV (6 Volts)
Subtract 6 volts from the 24 volt source to determine that 18 volts is available to power the F to I converter The 18 volts is
within the specified 10…30 volt range and is sufficient to power the F to I converter
Example 2
User Manual
Page 7 November 2013