Ee230
LISSAJOUS PATTERNS (INTRODUCTION)
OBJECTIVE
1. To use Lissajous figures to take phase measurements. 2. To use Lissajous figures to take frequency measurements.
LIST OF REQUIREMENTS
Equipment
1. General purpose oscilloscope (10MHz) 2. Function generators (1 Hz to 1 MHz) 3. Digital multimeter
THEORY
Lissajous patterns are formed when you combined periodic waves moving back and forth with periodic waves moving up and down. This exhibit does this electronically allowing the visitor to control the frequency of the X and Y motions independently. The resulting pattern can be observed on an oscilloscope and viewed on moving speakers. If the frequencies are high enough, the speakers produce sound. The combination of tones can be correlated with the scope pictures.
The oscilloscope can measure voltage, frequency, and phase angle. Two-channel measurements are very useful and are presented.We also can get lissajous figures in oscilloscope other than to get the waveform figures.
In electronic applications we can generate Lissajous patterns by applying different signals to the horizontal and vertical inputs of an oscilloscope. In facts, this techniques was often to used to measure frequencies in the days before frequency meters. A signal of a known frequency was applied to the vertical input. The resulting pattern was a function of the ratio of the two frequencies.
Lissajous Figures
A lissajous figure is produced by taking two sine waves and displaying them at right angles to each other. This easily done on an oscilloscope in XY mode.If the oscilloscope has the x-versus-y capability, one can apply one signal to the vertical deflection plates while applying a second signal to the horizontal deflection plates. The horizontal sweep section is automatically disengaged at this time. The resulting waveform is called Lissajous figure. This mode can be used to measure phase or frequency relationships between two signals.
When the
OBJECTIVE
1. To use Lissajous figures to take phase measurements. 2. To use Lissajous figures to take frequency measurements.
LIST OF REQUIREMENTS
Equipment
1. General purpose oscilloscope (10MHz) 2. Function generators (1 Hz to 1 MHz) 3. Digital multimeter
THEORY
Lissajous patterns are formed when you combined periodic waves moving back and forth with periodic waves moving up and down. This exhibit does this electronically allowing the visitor to control the frequency of the X and Y motions independently. The resulting pattern can be observed on an oscilloscope and viewed on moving speakers. If the frequencies are high enough, the speakers produce sound. The combination of tones can be correlated with the scope pictures.
The oscilloscope can measure voltage, frequency, and phase angle. Two-channel measurements are very useful and are presented.We also can get lissajous figures in oscilloscope other than to get the waveform figures.
In electronic applications we can generate Lissajous patterns by applying different signals to the horizontal and vertical inputs of an oscilloscope. In facts, this techniques was often to used to measure frequencies in the days before frequency meters. A signal of a known frequency was applied to the vertical input. The resulting pattern was a function of the ratio of the two frequencies.
Lissajous Figures
A lissajous figure is produced by taking two sine waves and displaying them at right angles to each other. This easily done on an oscilloscope in XY mode.If the oscilloscope has the x-versus-y capability, one can apply one signal to the vertical deflection plates while applying a second signal to the horizontal deflection plates. The horizontal sweep section is automatically disengaged at this time. The resulting waveform is called Lissajous figure. This mode can be used to measure phase or frequency relationships between two signals.
When the