ISO-STIM 01D User Manual
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version 4.3
page 13
5. Test Procedures
For the following test procedures a function generator is required. The frequency for testing
should be around 100 Hz, waveform is triangle. The value of the test pulse amplitude is always
described in detail for each of the following steps. In this test condition a load resistor of 100 k
is connected to the output plugs (red and black plugs).
5.1. DIRECT INPUT MODE
Settings
: INPUT MODE switch is in position DIRECT, OUTPUT MODE switch in position
VOLTAGE. Analog input voltage from a function generator is ±2 V and connected to the
SIGNAL INPUT BNC. Max. output voltage has to be ±20 V.
Caution
:
If you measure the output signal with an oscilloscope take care that the function
generator has not the same ground connection because of the isolation of the output. It is
important to realize that a connection is also possible through the protective ground connections
between oscilloscope and function generator (most mains supplied oscilloscopes have a
connection between ground and protective earth)! Thus, we recommend to use a battery driven
oscilloscope for test measurements to avoid unwanted grounding!
Now the OUTPUT MODE switch is set in position CURRENT (CURRENT RANGE switch
set to x1 µA) and the amplitude of the input signal is ±2 V. The max. signal at the isolated
output plugs has to be ±20 V according to the current of ±200 µA flowing through the load
resistance of 100 k
5.2. GATE TTL INPUT MODE
Settings
: INPUT MODE switch is in position GATE TTL, OUTPUT MODE switch in position
VOLTAGE. The TTL output of the function generator has to be connected to the GATE TTL
BNC, the SIGNAL INPUT BNC is not connected. The output voltage will be preset from the
value dialed at the AMPLITUDE potentiometer and the polarity from the position of the
corresponding toggle switch. Remember at any time Ohm’s law to realize what potentials
should be generated theoretically; the maximum output voltage of the system is ±100V.
5.3. ANALOG INPUT MODE
Settings
: INPUT MODE switch is in position ANALOG TRIG, OUTPUT MODE switch in
position VOLTAGE. Toggle switch for DURATION range in position 100 µs, TIME
potentiometer dialed on value 3. Input voltage from a function generator has to be positive
referring to ground, value 5 V and connected to the ANALOG INPUT BNC. Output voltage
will occur if the input voltage is higher than 300 mV (this is the internal analog trigger level)
and only for the desired time (here 300 µs). The output signal can be varied by using other input
amplitude values and / or several time settings.
Caution
:
If you are working in CURRENT MODE realize that the input resistance of an
oscilloscope is normally 1 M
, e.g. an oscilloscope connected to the outputs is a 1 M
load
for the current source producing an output signal that is measured.
