Externally Controlled Wobble Generator; Frequency Counter For External Frequencies - VOLTCRAFT 8202 Bedienungsanleitung

7.8 Externally controlled wobble generator

The wobble generator can also be adjusted via the VCF control input.
In order to apply the function generator as a voltage-controlled wobble generator, proceed as follows:
a) Set the function generator as described in 7.7. However, the knob „WIDTH" remains pushed (do not
pull out). You also do not have to make any adjustments on the knobs „RATE" or „WIDTH".
b) At the VCF input (5), apply a DC voltage-free, asymmetric alternating signal. The curve shape is of no
significance. Make sure that the dropping flank of the signal is larger than the rising flank (changed
symmetry).
We recommend attaching an oscilloscope to monitor or check the settings.
Never exceed the max. input parameters, neither on the VCF input nor on the fre-
quency counter input, and do not cause a short circuit on the generator outputs
"TTL/CMOS-OUT" and "OUTPUT". Otherwise you may damage or destroy the fre-
quency generator.
Danger of a mortal electric shock when exceeding the max. input parameters or
coming into contact with voltages in excess of 25 VAC or 35 VDC.

7.9 Frequency counter for external frequencies

The frequency generator can also be used as a frequency counter.
To do so, put the display into external counter mode via the switch „COUNTER INT/EXT" (17).
Switch depressed:
Switch not depressed:
Select the frequency range „FREQUENCY RANGE 1" (13).
The counter input (4) is labelled "EXT COUNT IN" and can be used for frequencies up to 50 MHz
In order to also measure low frequencies error-free (<100 kHz), the device features a „low-pass filter".
This suppresses high frequency shares (-3dB), which falsify measuring.
For frequency measuring below 100 kHz, always press the switch „LPF" (17). In case of high frequen-
cies, this switch may not be depressed.
The measuring signal must be electronically isolated from the mains. The amplitude
may not exceed 250 Vpp (peak-peak).
After applying a frequency of at least 2 Hz to max. 50 MHz with an electronically insulated signal voltage
and a max. amplitude of 250 Vpp (= peak-peak), it is displayed on the 6-digit display. Other buttons are
not required to operate the frequency counter. The decimal point, the measuring unit and the gate time
adjust automatically to the expected measuring signal. The input sensitivity is min. 100 mVrms.
Never exceed the max. input parameters, neither on the VCF input nor on the fre-
quency counter input, and do not cause a short circuit on the generator outputs
"TTL/CMOS-OUT" and "OUTPUT". Otherwise you may damage or destroy the fre-
quency generator.
Danger of a mortal electric shock when exceeding the max. input parameters or
coming into contact with voltages in excess of 25 VAC or 35 VDC.
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External counter mode
Internal generator display