b. Servo Switch
The right-hand toggle switch in the window at the front of the case ener-
gizes the servos and choppers. With this switch in the down position,
the recorder is in a "standbyt1 condition and the pen and carriage may be
moved by hand.
c. Scale Range Controls
The scale range controls are located on the control panel. Both stepped .
and continuously variable controls are provided. The scale positions
represent input voltages required to drive the X or Y axis from zero to
full scale. The volts/inch calibration of each axis is identical for cor-
responding fixed selector ranges (viz. 1. 5 v and 1.0 v on X and Y axes
respectively). Beneath each range selector is a two-.psition slider
switch for selection of either fixed or variable range. With this switch
in the "variable" position, the maximum voltage acceptance of any
range for full scale deflection can be continuously extended to about five
times its indicated value by adjustment of the ,potentiometer knob project-
ing through the center of the range selector knob. This feature can be
used to permit convenient fitting of experimental data to any portion of
the recording area. The volts/inch calibration of the instrument as de-
termined by the position of these controls does not change with the setting
of the zero control. CAUTION: Input voltages should never exceed 500
volts.
d. Time Sweep Control
Voltage range selection and time sweep selection are combined in the
same X-range switch. With the Volts-Time switch (on the rear function
panel) in "Volts" position, the recorder operates as a normal two-axis
plotter; with this switch in the "Time11 position, the X-axis operates as
a time base with sweep ranges (in seconds) corresponding to millivolt
values on the switch selector scale. Sweeps available in the standard
Model 2s are 7. 5, 15, 75, 150, and 750 seconds for full scale X-axis
pen travel. men operating with the sweep circuit, variations in full
scale time intervals of up to five times the calibrated values may be ob-
tained by placing the X-range expander switch in the "VAR1f position
and adjusting the top knob of the range control. Use in this manner will
not disturb the basic calibration of the timing circuits.
e. Zero-Setting Controls
The zero-setting controls are located on the control panel and consist of
10-turn potentiometers with counting dials. By means of the zero- setting
controls the electrical zero of the instrument can be set anywhere on the
paper, or up to one scale-length to the left and below the lower-left hand
8 |
ACEC
