© National Instruments
|
1-9
RMX Programmable Power Supplies User Manual
Loads that Generate Reverse Current to the Power Supply
RMX programmable power supplies cannot sink reverse current from the load. Therefore, if a
regenerative load (such as an inverter, converter, or transformer) is connected and tries to sink
power into the terminals of the power supply, the output voltage will increase and can become
unstable. This can cause a malfunction.
For these types of loads, connect a resistor (R
D
) as shown in the following figure to bypass the
reverse current. However, the amount of current to the load decreases by I
rp
.
Figure 1-7.
Loads with Accumulated Energy
Caution
Use a resistor with sufficient rated power for R
D
. If a resistor with
insufficient rated power for the circuit is used, the resistor will burn out.
Loads with Accumulated Energy
Connecting a load with accumulated energy, such as a battery, to an RMX programmable power
supply may cause current to flow from the load to the internal circuit. This current may cause
damage or reduce the life of the load.
For this type of load, connect a reverse-current-prevention diode (D
RP
) between the RMX
programmable power supply and the load in series as shown in the following figure.
This cannot be used in conjunction with remote sensing.
Figure 1-8.
Loads with Accumulated Energy
I
O
R
D
E
O
Equivalent circuit of the RMX-4122
Regenerative load
＋
0
Reverse current
-
I
O
+
I
O
I
rp
R
D
(in Ω) ≤
R
D
: Reverse current bypass dummy load
E
O
: Output voltage
Irp: Maximum reverse current
EO (in V)
Irp (in A)
Load
Output current
RMX-4122
Load with accumulated energy
D
RP
: Reverse-current-protection diode
D
RP
