Doepfer A-198 Trautonium / Ribbon Controller - Manual (Page 4)

A-198 Trautonium / Ribbon Controller System A - 100 doepfer
4
the Trautonium the sound disappears immediately if
the finger is removed (no release).
3 LED
The LED 3 monitors the Gate signal at output " that
is triggered by touching the position sensor (active
only in the Off position of the Hold switch).
4 Thres
Control 4 is used to set the Trigger Threshold above
which a Gate signal is generated (see fig. 2). Whene-
ver the pressure control voltage exceeds the threshold
the Gate output $ turns to high.
5 LED
The LED 5 monitors the Gate signal at output $ that
is generated whenever the pressure control voltage
exceeds the threshold adjusted with control 5.
6 Scale
The pressure Scale, i.e. the connection between pres-
sure and the voltage CV
PRES
generated at output §, is
adjusted with control 6.
Fig. 2: Connection between the Gate signals and the
finger pressure (Gate
POS
is shown for Hold = Off)
The pressure sensor is made with conductive rubber
and does not work as accurate as the position sensor.
The resistance of the conductive rubber changes with
varying pressure and causes a variable voltage. But
the coherence between pressure and resistance/vol-
tage is not very accurate - except that an increasing
pressure will cause an increasing voltage. Even some
difference of the pressure sensor behaviour over the
length of the manual may be possible as the conduc-
tive rubber has tolerances over this length.
Gate
POS
t
Gate
PRES
t
Pressure
t
Touch Release
Threshold