Fluke 6105A - Four-Wire Sense; Two-Wire; Four-Wire Configuration Settings

6100B/6105A
Getting Started
22
Four-wire Sense
In two-wire sensing, the sense point for the control system feedback loop is at the back of
the terminals. Any current flowing in the leads connecting the OUTPUT terminals to the
load causes a volt drop in the leads. As a result, the voltage at the load is less than at the
terminals and accuracy is compromised. This problem is solved by using four-wire
sensing as shown in Figure 11.
The input impedance of the feedback amplifier is very high so very little current flows in
the sense leads. The voltage input to the SENSE terminals therefore accurately represents
the voltage across Z
Load and this is used to correct the voltage at the OUTPUT terminals.
1430V
Pk
MAX
VOLTAGE
OUTPUT
SENSE
1V Pk
MAX
1V Pk
MAX
46V Pk
MAX
HI
LO
HI
LO
Z
Load
I
gdw08.eps
Figure 11. Four-wire Sense Configuration
Two-wire / Four-wire Configuration Settings
The 2-wire / 4-wire configuration applies to all connected Master and Auxiliary units.
The configuration is made via a pop-up menu called from the Global Settings Menu top-
level softkeys. See Figure 12.
gdw14.bmp
Figure 12. Global Settings Menu Top-level Softkeys
Push the Front Panel Terminals softkey to open the pop-up screen. See Figure 13.