STANDARD SIGNAL GENERATOR
A standard signal generator produces known and controllable voltages. It is used as power source for the measurement of gain, signal to noise ratio (SN), bandwidth standing wave ratio and other properties. It is extensively used in the measuring of radio receivers and transmitter instrument is provided with a means of modulating the carrier frequency, which is indicated by the dial setting on the front panel. The modulation is indicated by a meter. The output signal can be Amplitude Modulated (AM) or Frequency Modulated (FM). Modulation may be done by a sine wave, Square, rectangular, or a pulse wave. The elements of a conventional signal generator
The carrier frequency is generated by a very stable RF oscillator using an LC tank circuit, having a constant output over any frequency range. The frequency of oscillations is indicated by the frequency range control and the venire dial setting. AM is provided by an internal sine wave generator or from an external source.
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Sine and Square wave be generated using Signal Generator
The signal generator is called an oscillator. A Wien bridge oscillator is used in this generator. The Wien bridge oscillator is the best of the audio frequency range. The frequency of oscillations can be changed by varying the capacitance in the oscillator. The frequency can also be changed in steps by switching the resistors of different values. The output of the Wien bridge oscillator goes to the function switch. The function switch directs the oscillator output either to the sine wave amplifier or to the square wave shaper. At the output, we get either a square or sine wave. The output is varied by means of an attenuator.
The instrument generates a frequency ranging from 10 Hz to 1 MHz continuously variable in 5 decades with overlapping ranges. The output sine wave amplitude can be varied from 5 mV to 5 V (rms).The output is taker through a push-pull amplifier. For low output, the impedance is 6000. The square wave amplitudes can be varied from 0 - 20 v (peak). It is possible to adjust the symmetry of the square wave from 30 -70%. The instrument requires only 7W of power at 220V 50Hz. The front panel of a signal generator consists of the following.
l. Frequency selector : It selects the frequency in different ranges and varies it
continuously in a ratio of 1: 11. The scale is non-linear.
2. Frequency multiplier : It selects the frequency range over 5 decades from 10 Hz to 7 MHz
3. Amplitude multiplier : It attenuates the sine wave in 3 decades, x l x 0.1 and x 0.01.
4. Variable amplitude : It attenuates the sine wave amplitude continuously
5. Symmetry control : It varies the symmetry of the square wave from 30% to 70%
6. Amplitude : It attenuates the square wave output continuously.
7. Function switch : It selects either sine wave or square output.
8. Output available : This provides sine wave or square wave output.
9. Sync : This terminal is used to provide synchronization
of the internal signal with an external signal.
10. On-Off Switch
A standard signal generator produces known and controllable voltages. It is used as power source for the measurement of gain, signal to noise ratio (SN), bandwidth standing wave ratio and other properties. It is extensively used in the measuring of radio receivers and transmitter instrument is provided with a means of modulating the carrier frequency, which is indicated by the dial setting on the front panel. The modulation is indicated by a meter. The output signal can be Amplitude Modulated (AM) or Frequency Modulated (FM). Modulation may be done by a sine wave, Square, rectangular, or a pulse wave. The elements of a conventional signal generator
The carrier frequency is generated by a very stable RF oscillator using an LC tank circuit, having a constant output over any frequency range. The frequency of oscillations is indicated by the frequency range control and the venire dial setting. AM is provided by an internal sine wave generator or from an external source.
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Sine and Square wave be generated using Signal Generator
The signal generator is called an oscillator. A Wien bridge oscillator is used in this generator. The Wien bridge oscillator is the best of the audio frequency range. The frequency of oscillations can be changed by varying the capacitance in the oscillator. The frequency can also be changed in steps by switching the resistors of different values. The output of the Wien bridge oscillator goes to the function switch. The function switch directs the oscillator output either to the sine wave amplifier or to the square wave shaper. At the output, we get either a square or sine wave. The output is varied by means of an attenuator.
l. Frequency selector : It selects the frequency in different ranges and varies it
continuously in a ratio of 1: 11. The scale is non-linear.
2. Frequency multiplier : It selects the frequency range over 5 decades from 10 Hz to 7 MHz
3. Amplitude multiplier : It attenuates the sine wave in 3 decades, x l x 0.1 and x 0.01.
4. Variable amplitude : It attenuates the sine wave amplitude continuously
5. Symmetry control : It varies the symmetry of the square wave from 30% to 70%
6. Amplitude : It attenuates the square wave output continuously.
7. Function switch : It selects either sine wave or square output.
8. Output available : This provides sine wave or square wave output.
9. Sync : This terminal is used to provide synchronization
of the internal signal with an external signal.
10. On-Off Switch
