Sunday, April 2, 2017

Week 11:

Part A: Strain Gauges:
Circular Gauge:

Flipping strength Minmun Voltage (volts) Maximum Voltage (volts)
Low -2.5 4.8
High -3.4 10

Square Gauge:

Flipping strength Minmun Voltage (volts) Maximum Voltage (volts)
Low -10.2 7.5
High 8.32 12

Part B: Half-Wave Rectifiers
Number 1:

Number 2:

Effective (rms) Calculated (volts) Measured (volts)
Input 7.64 7.52
Output 3.44 5.39

Number 3:
To get calculated RMS value of the input we multiplied the peak by .707 voltage. And to get calculated RMS  output we decided the peak by pi. The calculated and measured for the input line up well enough but not for the output we assume it's because the rectifier didn't fully remove the negative voltage signal.

Number 4:
Output voltages from above circuit:

Oscilloscope (volts) DMM (volts)
Output Voltage (P-P) 5 3.7
Output Voltage (Mean) 6.5 6.28
Number 5:

Same output voltages from Num. 4 but with a 100 nanoF capacitor.

Oscilloscope (volts) DMM (volts)
Output Voltage (P-P) 0.24 0.0567
Output Voltage (Mean) 7.17 7.16

Part C: Energy Harvesters
Number 1:
Tapping Table:

Tap Freq Duration (seconds) Outout (rms mV)
1 Flip/Sec 10 242
1 Flip/Sec 20 413
1 Flip/Sec 30 513
4 Flip/Sec 10 280
4 Flip/Sec 20 742
4 Flip/Sec 30 773
Flipping Table:
Tap Freq Duration
Outout (rms mV)
1 Flip/Sec 10 230
1 Flip/Sec 20 290
1 Flip/Sec 30 640
4 Flip/Sec 10 840
4 Flip/Sec 20 1430
4 Flip/Sec 30 1600

Number 2:
The longer that you tap it and/or the faster you tap it the more the circuit seems to store generate more voltage and hold that voltage for longer.

Number 3:
If we don't use the diode in the circuit then the strain gauge won't charge the capacitor  at all.

Number 4:


  1. For problem A I found that we have different values and graphs than what you have maybe because we have different ranges or we had a mistake in that part.
    For problem C from the graphs I found that we have same results even if we had different numbers.
    Good job.

  2. For A and B we had similar data but we showed ours a bit differently. for B we showed the input and output on the oscilloscope picture to give a better representation. But for part C for 4flips/second our voltage decreased rather than increased like yours. we also had issues measuring the mean with the DMM, how did you guys calculate or measure that value?

  3. Our blogs look very similar our values and our graphs both look similar. The only part that seems different is in part C you guys did both strain gauges we only did one. Were we suppose to do both?

  4. Nice work for this week. For part A, we almost have the same values for both flapping strain gauge and tapping strain gauge. For Q2 in part B, We had the same issue with the result of the output and the calculated output wasn't close to our measured input, I think that is because we measured the output before the rectifier remove the negative signal completely. Captions are missing for all tables and graphs.

  5. Good job this week. The blog is pretty easy to read and the data tables and graphs are really well represented. The only difference I can see is how the Matlab graph increased for you guys, on the other hand it decreased for us.