ELC-03XS User Manual
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version 2.2
page 15
CAPACITY COMPENSATION (VC) unit
The CAPACITY COMPENSATION (VC) unit consist of (
28
) TIME
CONSTANT (
-FAST) potentiometer and of (
32
) AMPLITUDE (C-FAST)
potentiometer. It compensates for the electrode capacity and functions only in
VC mode. Tuning is done by application of voltage pulses to the electrode and
trying to get the resulting current pulses as fast as possible using potentiometers
28
and
32
.
(
28
) TIME CONSTANT (
-FAST) potentiometer
Potentiometer for setting
-FAST in the electrode capacity compensation circuit.
(
32
) AMPLITUDE (C-FAST) potentiometer
Potentiometer for setting C-FAST in the electrode capacity compensation circuit.
Note
: CAPACITY COMPENSATION works only for the electrode capacity, not for the
capacity of the cell membrane. Therefore, capacitive transients are always present when
square shaped pulses are applied in VC mode.
(
29
) GROUND connector
Banana jack providing system GROUND. System GROUND is not connected to the
chassis or to protective earth, respectively.
(
30
) POWER switch
Push button to switch the amplifier ON (pushed) or OFF (released).
(
31
) AUDIO volume potentiometer
Potentiometer for setting the volume of the AUDIO monitor for POTENTIAL.
Turning the potentiometer clockwise increases the volume.
(
33
) PIPETTE HOLD POTENTIAL (VC)
Ten-turn potentiometer setting the current through the pipette to zero when
approaching a cell in VC mode, i.e. the pipette is clamped to its OFFSET potential
resulting in zero current flow through the pipette. In VCx10 mode the pipette hold
potential does not change. Range is
100 mV and zero position is 5, i.e. the same as the
OFFSET potentiometer
50
. This is very convenient since this adjustment can be done starting
with the same value as in
50
.
