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university:courses:electronics:electronics-lab-eh [23 Mar 2017 15:27]
Doug Mercer [Materials:]
university:courses:electronics:electronics-lab-eh [02 May 2017 12:27]
Antoniu Miclaus [Procedure:] replace plot
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 Energy harvesters provide only a very small amount of power for low-energy electronics. While the energy source for grid-scale generation plants costs money (oil, coal, gas etc.), the energy source for energy harvesters is present in the ambient background and is thus free. Energy harvesters provide only a very small amount of power for low-energy electronics. While the energy source for grid-scale generation plants costs money (oil, coal, gas etc.), the energy source for energy harvesters is present in the ambient background and is thus free.
  
-The piezoelectric transducer, LDT0 supplied in the Analog Parts Kit is a flexible film device laminated to a polymer substrate. Two crimped contacts for mounting and electrical connections are provided. When the device is bent or displaced from its neutral position, a very high strain is generated in the piezo-polymer and a high voltage is generated. As a vibration sensor the LDT0 has a sensitivity of 50 mV/g. An electrical model of a typical piezoelectric device is shown in figure 1.+The piezoelectric transducer, LDT0 supplied in the ADALP2000 ​Analog Parts Kit is a flexible film device laminated to a polymer substrate. Two crimped contacts for mounting and electrical connections are provided. When the device is bent or displaced from its neutral position, a very high strain is generated in the piezo-polymer and a high voltage is generated. As a vibration sensor the LDT0 has a sensitivity of 50 mV/g. An electrical model of a typical piezoelectric device is shown in figure 1.
  
 {{ :​university:​courses:​electronics:​aeh_f1.png?​370 |}} {{ :​university:​courses:​electronics:​aeh_f1.png?​370 |}}
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 ===== Procedure: ===== ===== Procedure: =====
  
-Connect the Analog Discovery ​hardware as indicated by the green boxes. Set both scope channels to 1V/div. With the horizontal time base set to 200mS/Div and trigger set to none, rapidly flick the transducer back and forth with your finger. Observe the voltage waveform across the transducer on channel 1 and the rectified and filtered DC voltage on channel 2. What you observe should look much like the screen shot shown in figure 3. The channel 1 waveform in orange shows the vibrating waveform produced by the transducer as it is flicked back and forth. The channel 2 waveform in blue shows the DC voltage charging up from zero volts to higher voltages each time the transducer vibrates.+Connect the ADALM2000 ​hardware as indicated by the green boxes. Set both scope channels to 1V/div. With the horizontal time base set to 200mS/Div and trigger set to none, rapidly flick the transducer back and forth with your finger. Observe the voltage waveform across the transducer on channel 1 and the rectified and filtered DC voltage on channel 2. What you observe should look much like the screen shot shown in figure 3. The channel 1 waveform in orange shows the vibrating waveform produced by the transducer as it is flicked back and forth. The channel 2 waveform in blue shows the DC voltage charging up from zero volts to higher voltages each time the transducer vibrates.
  
 The large but still finite 1 megaohm input resistance of the scope channel will load down the peak voltage generated by the transducer. Remove the connection to scope channel 1 and again rapidly flick the transducer. The DC voltage seen at the output should be significantly higher now. The large but still finite 1 megaohm input resistance of the scope channel will load down the peak voltage generated by the transducer. Remove the connection to scope channel 1 and again rapidly flick the transducer. The DC voltage seen at the output should be significantly higher now.
  
-{{ :​university:​courses:​electronics:​aeh_f4.png?550 |}}+{{:​university:​courses:​electronics:​ener_harv_plot.png|}}
  
 <WRAP centeralign>​ Figure 3 Scope Screen shot when flicking transducer rapidly </​WRAP>​ <WRAP centeralign>​ Figure 3 Scope Screen shot when flicking transducer rapidly </​WRAP>​
university/courses/electronics/electronics-lab-eh.txt · Last modified: 02 May 2017 12:27 by Antoniu Miclaus