3B Scientific Control Unit for Critical Potential Tubes (115 V, 50__60 Hz) - Manual (Page 2)

2
is possible to trace the curve for the collector
current on an oscilloscope. The in-built SLOW
function allowing for a lower frequency (1/6 Hz
approx.) enables recording of this characteristic
with the aid of a slower measuring interface or
an XY plotter.
The equipment with the order number 1000633
includes a plug-in power supply for a mains volt-
age of 115 V (±10%), whereas the one with order
number 1008506 includes one for 230 V (±10%).
2. Controls
Output 1 is designed to supply the saw-tooth
accelerating voltage V
A
. The initial voltage is set
using knob 4 and the final voltage is set via knob
3.
To set the desired parameters for the saw-tooth
voltage, a multimeter can be connected into
circuit. The voltage measured between socket 3
and ground (V
A
MAX) or socket 4 and ground
(V
A
MIN) is smaller than the actual voltage by a
factor of 1000.
The collector current I
C
(pA) is fed to the equip-
ment via socket 2 (BNC socket). When amplified
by the built-in picoamp amplifier, the current can
be measured via the terminals of an oscillo-
scope/data logger in the form of an equivalent
voltage (1 V/nA).
To display the collector current as a function of
the accelerating voltage, the XY mode of the
oscilloscope can be used. You can record the
relevant voltages at 20 Hz by connecting the
scope to the FAST output.
The SLOW output allows values to be output at
lower frequency using a slow interface or an XY
plotter. The output is provided by means of a
built-in sampling method by pressing the SLOW
RUN button.
When the SLOW function is activated the LED
will light up in green. When it finishes, the LED
will turn back to red.
In both cases, the output for the saw-tooth volt-
age is taken from socket 1 (Y deflection) and the
output from the measuring amplifier is from out-
put 2 (X deflection).
3. Technical data
Supply voltage: 12 V AC
Current measurement: 1 V/nA, BNC
Output voltage:
0 - 60 V/20 Hz, saw-
tooth
Measurement output: Socket 1: 0 - 1 V, pro-
portional to output volt-
age
Socket 2: 0 - 1 V, pro-
portional to collector
current I
C
Operating modes: FAST: measurement
output 20 Hz
SLOW: measurement
output 1/6 Hz
Dimensions: 170x105x45 mm approx.
4. Operation
• Connect the control unit to its plug-in power
supply. The socket for it is on the base of
the equipment.