Gamry Instruments IMX8, Operator'S Manual, Page: 16 / 43

Introduction
16
Figure 2-2
Simplified Schematic of a Single IMX8 Channel
The cell cable from the system potentiostat is connected at the left side of the schematic. The system-
potentiostat cell cable can be connected to any of the IMX8 channels. The system computer must ensure that
only one cell at a time is connected to the system potentiostat.
Switch S1 controls which cell is active. S3 and S4 control the inactive mode of the cell on this channel.
Looking at the schematic, you can see that switch S1 connects this channel’s cell to the system potentiostat. An
active channel always has S3 and S4 open. The relays in S1 are rated to carry 1.5 A and switch 500 mA. You
can normally use the IMX8 with potentiostats rated at up to 100 V of output compliance and 1.5 A of output
current.
To avoid transients, Gamry’s software always turns off the cell at the system potentiostat prior to switching S1 .
The IMX8 switches all its relays nearly simultaneously (even those in different channels), but there is still about
1 millisecond in which the relay pattern in the IMX8 is in neither the initial or final configuration. Switching
transients as the IMX8 switches channels with a “live” potentiostat can be particularly severe because the
system potentiostat’s feedback goes through one of the
S1 relays. To avoid the problem, turn off the cell at the
system potentiostat before switching channels.
You have a choice of three different control schemes for inactive cells. These are tabulated in Table 2-1 along
with the active mode.