Day 17: Electronics

Measuring Changing Voltages

We attached a function generator to our oscilloscope and set the function generator to 96 Hz. The result was the above pictured sinusoidal wave. We were asked to determine its theoretical and experimental period. In order to determine the theoretical period we used t=1/f, where t=period and f=frequency. Since we knew our frequency we just plugged in the values and got t=0.010417 s. Based on our graph we found the period for one cycle of the wave. We determined that the wave's period was 5.1. However, we needed to multiply this by our time division of 2 ms. Therefore our experimental period was t=(5.1*.002)=0.0102 s.

These pictures show what occurred when we changed the sinusoidal wave to a triangle wave (left) and square wave (right). 

Power Supply (DC Source)

For this next experiment we were asked to find the amplitude and period. We determine the amplitude of the DC Power Supply to be roughly 39 mV. The period however was much more difficult to determine and we were unable to find it. 

AC Transformer

For the AC Transformer we were again asked to determine amplitude and period. This was much easier because the wave that was emitted was sinusoidal in nature. We found the amplitude to be 20 V and the period to be t=(8.51*.002)=.01702. For this transformer we also found the frequency which was f=58.8 Hz. 

Lissajous Figures (Using AC Transformer)

This time around we connected the same AC Transformer as before to CH 1 and the Function Generator to CH 2. The function generator was set to 30 Hz and the oscilloscope was set up so that in the XY mode we could see Lissajous Figures of the to channels. At 30 Hz we got the above shape that twisted and rotated over time.

When we set the Function generator to 60 Hz, the shape was clearly circular/oval. This shape too rotated about. 

Mystery Box: Solve Whats In It.

We were given a mystery box and told to determine which waves or frequencies it consisted of. The bellow pictures are a summary of our findings. 

Red and Black

Square Frequency

Amplitude=4 V

Period=0.0044 s

Red and Blue

Square Frequency

Amplitude=1.8 V

Period=0.0043 s

Red and Green

Square Frequency

Amplitude=4 V

Period=0.0042 s

Blue and Black

Square/Sinusoidal Frequency

Amplitude=0.02 V

Period=0.003 s

Green and Black

Sinusoidal/Square Frequency

Amplitude=0.008 V

Period=0.0044 s

Although there are other options, none of them produced real results. Yellow for example produced no real waves in combination with any of the possible colors. Other combinations also had the same result or resulted in a lot of noise/static. This we determined that the mystery box had some combinations of square and sinusoidal frequencies.