1. Energy Harvesting Name: Alex Phipps Goals: Key accomplishments.
Measure and characterize the efficiency of each stage of the direct charging circuit.
Compare efficiency measurements to simulation data.
Completely understand Shengwen’s circuits
Key accomplishments.
Gathered and processed data for efficiency of direct charge.
Measured mechanical power into the system.
Calculated efficiency for mechanical to electrical conversion.
Calculated electrical efficiency for the rectifier circuitry.
Key issues
Simulations do not match up with the measurements.
The sims are very inefficient.
Measured efficiencies are low because of losses on resistors.

2. Beam Data
Mechanical data was gathered using an accelerometer and a displacement sensor.
Vaccel (p2p) [mV]
Acc (rms) [m/s^2]
F(rms) [N]
disp (rms) [m]
velocity (rms) [m/s]
Power Beam [uW] 44
4.0882
4.4970E-04
1.31E-04
1.64E-01
73.87
56.6
5.3726
5.9099E-04
1.74E-04
2.18E-01
128.70
66.4
6.2869
6.9156E-04
2.11E-04
2.64E-01
182.67
76.4
7.3074
8.0381E-04
2.49E-04
3.11E-01
250.18
85.6
8.0942
8.9036E-04
2.81E-04
3.51E-01
312.43
97.2
9.1986
1.0118E-03
3.20E-04
4.00E-01
404.28
108
10.165
1.1182E-03
3.51E-04
4.39E-01
490.89

3. Beam Efficiency
Beam efficiency is defined as electrical power from the beam
divided by mechanical power into the beam.

4. Electrical statistics
Vin (rms) [V]
Iin (rms) [A]
Power In [uW]
Vbat [V]
Ibat [A]
Power battery [uW] 2
1.967
9.54E-06
18.77
4.00E-06
8.00
2.045
1.12E-05
22.94
5.90E-06
11.80
2.1197
1.34E-05
28.30
8.00E-06
16.00
2.1714
1.52E-05
32.94
9.75E-06
19.50
2.2231
1.71E-05
37.97
1.18E-05
23.50
2.1998
1.87E-05
41.06
1.35E-05
27.00

5. Converter Efficiency

6. Overall Efficiency
Total Efficiency = Converter Efficiency*Beam Efficiency