Research Procedures
Hybrid Energy Systems Laboratory

 Figure 1

 

 Figure 2

 

 Figure 3

 

Figure 4

Current requirements for various cell phone operations were measured by replacing the battery with a contstant 3.7 V from a power supply and monitoring the current output (Figure 1).

 

 

 

 

The strain gauge was calibrated using standard masses, and then was used to measure the keystroke forces delivered to a cell phone (Figure 2).

 

 

 

 

An accelerometer was used to measure the motion of the phone in all 3 directions when ringing an vibrating (Figure 3).

 

 

 

 

 

The piezoelectric devices were subjected to accelerations experienced by the ringing and vibrating phones using a shaker device, and their power output was recorded (Figure 4).