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Active Loads
The voltage drop (per output or return lead) could be calculated using
the following equation:
V = I x L x R20°C x [1 + 0.004 x (T - 20°C)]
where,
N
OISE AND
To minimize noise pickup or radiation from load circuits, load wires
and remote sense wires should be twisted-pair with minimum lead
length. Shielding of the sense leads may be necessary in high noise
environments. Even if noise is not a concern, the Source and remote
sense wires should be twisted-pairs to reduce coupling between them,
which could impact the stability of the system. If connectors are
utilized for the power and sense leads, be careful not to introduce
coupling between the leads. Ensure that the connector terminals for
the sense leads are in adjacent locations, and minimize the physical
loop area of the untwisted portions.
Twisting the load wires provides an additional benefit in reducing the
parasitic inductance of the cable. This improves the dynamic
response characteristics of the load by maintaining a low source
impedance at high frequencies. Also, with long load wires, the
resultant inductance and resistance could produce high frequency
voltage fluctuations at the load because of current variations in the
load itself or reduce the dynamic performance.
OPERATION
7.5
The Active Load modules function within the ReFlex Power™ system under
remote control through a host controller. The ReFlex Power™ Controller
module serves as a communications portal between the power supply
modules and the remote host controller. All aspects of operation could be
achieved through use of commands that comply with the requirements of
the SCPI Standard 1997 command language. Additional discrete digital and
optional analog control signals are available for dedicated hardware
interface. All connectors for control and power interface are accessible on
the front panel
7-24
V = total voltage drop, V
I = current, A
L = length of wire, m
R20°C = resistance of wire, Ω/m, at 20°C
T = temperature of wire conducting current, °C
I
E
MPEDANCE
FFECTS
ReFlex Power™
M380056-01 Rev L
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