VOLTCRAFT FG 8210 Bedienungsanleitung Seite 32

To change the symmetry of basic curves, proceed as follows:
• Set the function generator as described in chapter "7.4 Basic Setting" and connect output (7) to an oscilloscope.
Always use a 50 Ohm end resistor to avoid signal distortions.
• Select the desired basic curve form by operating the corresponding switch in the field "FUNCTION". Push the
switch for rectangular signals to receive needle impulses, the switch for triangular signals for ramps or saw-teeth
or the switch for sine signals for an elongated sine.
• For extremely short increase times and long drop times (ratio up to and exceeding 1:10), pull the adjustment
button "SYM" and turn it to the left (max. "Asymmetry" to the left stop). For extremely long increase and very short
drop times, turn the adjustment button "SYM" to the right (max. "Asymmetry" to the right stop).
The symmetry adjustment changes the frequency and therefore should be re-adjusted.
Never exceed the max. input values, neither at the VCF-input nor at the frequency counter input,
and avoid a short circuit at the generator outputs "TTL-OUT" and "OUTPUT". Otherwise, there is
the danger of damage or even destruction of the frequency generator.
When the max. input values are exceeded or voltages above 50 VAC or 75 VDC are touched, there
is the danger of a potentially fatal electric shock.
To better set the ratio at a ramp (triangle) or an elongated sine, we recommend pushing the switch for the rec-
tangular signal "FUNCTION". Then determine the period duration of the drop and rise time at the oscilloscope
and set them with the generator to the desired values (with adjustment button "SYM" and "FREQUENCY").
Then select the desired signal form.
8.3 TTL-SYNCHRONOUS OUTPUT
The TTL-output is intended for specific logic circuits. The TTL-level is fixed in its amplitude (voltage height). Fre-
quency and symmetry are bound to the basic signal. A DC offset adjustment is not possible. The level is above the
zero line.
Connect a shielded 50 Ohm-BNC-measuring line with alligator clamps at the TTL-output (6). Connect the red clamp
(signal) to the cycle input of the logic circuit, the black terminal (ground) to the ground of the logic circuits.
The TTL-output can be used as "true" cycle generator for TTL-circuits. This output can be used to "drive" all
TTL circuits.
Never exceed the max. input values, neither at the VCF-input nor at the frequency counter input,
and avoid a short circuit at the generator outputs "TTL-SYNC" and "OUTPUT". Otherwise, there is
the danger of damage or even destruction of the frequency generator.
When the max. input values are exceeded or voltages above 50 V/AC or 75 V/DC are touched,
there is the danger of a potentially fatal electric shock.
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