Electrical Power Transfer with “No Wires” - Energy Harvesting Autonomous Sensor Systems - page 193

CH1 = 2 V
DC 1:1

CH2 = 2 V
DC 1:1

CH3 = 5 V
DC 10:1

200 ms/div
(200 ms/div)
NORM: 5 kS/s

Expanded
View

= Trace1 =
= Trace2 =
= Trace3 =

Max
Max
Max

6.720 V
6.000 V
4.200 V

Min
Min
Min

4.000 V
0.000 V
-600.0 mV

Avg
Avg
Avg

5.354 V
4.115 V
634.7 mV
50 ms/div

CH1 = 2 V CH2 = 2 V CH3 = 5 V

Output Voltage of
Linear Regulator

12-Bit Encoded Data Received
on RF Receiver Side

Charging and Discharging
Output Voltage Waveforms of
Energy Storage and Supply
Circuit

FIGURE 6.12
Waveforms collected at the RF receiver side to display the number of 12-bit encoded data packets
received using the harvested energy.

as compared to other energy harvesting sources (i.e., solar and wind), the
small amount of energy of 685 J was sufficient to power its RF transmitter

load to transmit several digital-encoded data in wireless transmission. The
experimental results demonstrating the successful RF transmission using the
harvested energy are shown in Figure 6.12 . This implies that the magnetic
energy harvester was able to meet its objective.

Processed
Electrical Energy
(DC)

Inductively
Coupled Power
Transfer, P

Raw Electrical
Power (DC)

Voltage
Doubler

Energy Storage
and Supply

Linear Voltage
Regulator

RF
Load

Power Required for One 12-
Bit Digital Word Is 13.2 mW
Energy Required for One 12-
Bit Digital Word Is 132 uJ

V ac,rms = 3.60 V
I ac,rms = 2 mA
P in = 7.20 mW

V dc = 6.72 V
I dc = 0.64 mA
P o = 4.30 mW

FIGURE 6.13
Line diagram of the power flow in the system.