Centrad GF 266, Instruction Manual

Page: 32 / 52

- 32 -
4000 4 319 _EN - 04/12
ENGLISH
7 - TYPICAL APPLICATIONS
7-1 AMPLIFIER FREQUENCY RESPONSE
Connect the function generator output to the input of the amplifier to be tested after suitably adjusting the amplitude.
At the correctly loaded output, display the signal on an oscilloscope. Vary the frequency, noting the variation of Vout
with reference to Vin. The ratio will be in dB: 20 Log IVs/VeI.
The roll-off frequency at -3dB will be reached when, with Vin constant, Vout will have decreased in a ratio of
√
2, i.e.
1.414.
With a square signal at the amplifier input, it is possible to view abnormal conditions at the output, such as: overshoot,
bouncing, rise time ...
Better than a sine wave, a triangular signal gives the maximum level before clipping.
7-2 TRANSISTOR AMPLIFIER WITHOUT EXTERNAL POWER SUPPLY (Fig . 18)
Set the power supply voltage using the offset adjustment button [12].
Activate the -20dB attenuator. Adjust the signal shape, frequency and amplitude.
Connect the generator output to Vin.
7-3 FREQUENCY RESPONSE:
The Sweep lin or log modulation schemes cause frequency sweeping. An oscilloscope connected to the output of
the stage to be tested automatically shows the response curve.
7-4 SWITCHING LEVELS:
To dynamically test the switching levels of comparators or different logic families, use a low-frequency triangular signal
of suitable amplitude and offset.
7-5 SYSTEM ANALYSIS:
Low-frequency square, triangular or sine wave signals can be used to analyse servo systems, highlighting the following:
static error, linearity, accuracy, stability ...
8 - MAINTENANCE
No special maintenance is required for this unit. Avoid dust, moisture and shocks. To clean the generator, use a soft
cloth.
If the display does not light up at power-on, check:
- if the On/Off switch is in On position (
I
) - mains voltage presence
- connection to the mains - the protective fuse (T200mA)
9 - AFTER-SALE SERVICE
After-sale service is provided by elc .
The function generator is guaranteed parts and labour for two years. Excluded of the warranty are failures or defects
resulting from misuse (improper mains voltage, shocks...) or repair by other than elc or approved repair centres.
Vcc
Vcc
Ve
Fig . 18