V21B Mide Technology Corporation, V21B Datasheet

Page 1

... TYPICAL APPLICATION PIEZOELECTRIC ENERGY HARVESTERS DESCRIPTION Volture™ vibration energy harvesters convert otherwise wasted energy from mechanical vibrations into useable electrical energy. The Volture™ accomplishes this by utilizing normally brittle piezoelectric materials. The Midé Volture™ energy harvester is unique amongst other piezo based energy harvesters because it incorporates Midé ...

Page 2

... REVISION N0. 001 REVISION DATE: 06-03-2010 .865 .690 V20W .600 1.250 V25W 1.500 .100 2 X .129 .300 V21B .600 .660 .100 .110 1.085 .300 .910 V21BL .600 .660 .100 2 X .110 V22B .240 .600 .100 1.290 .883 V22BL .240 .600 .100 2 ...

Page 3

... V22B 0.03 V22BL 0.12 ELECTRICAL CHARACTERISTICS Single Wafer Series Product Capacitance (nF), measured at 100 Hz V20W 69 V25W 130 V21B 26 V21BL 26 V22B 9 V22BL 9 - -40 to 150 C - -60 to 150 C 300 C 800 micro-strain* Product and Vibration Dependent** Product and Vibration Dependent** FIXED TO VIBRATING SURFACE Single Wafer Series ...

Page 4

... AC waveform as the Volture deflects in both directions. For sensing or dual-use applications where it is desired to know the direction of deflection at any given time, please refer to the relationship between deflection and output polarity for each wafer diagram below REVISION N0. 001 REVISION DATE: 06-03-2010 OUT OUT + V20W - + V25W - V21B / BL V22B / BL 4 ...

Page 5

... The first step in successful energy harvesting is to fully understand the vibration environment in which the Volture™ will be operating. The most effective means to accomplish this is to measure the vibration using an accelerometer, capture the data, and perform an FFT (Fast Fourier Transform) on the data to extract the relevant frequency information ...

Page 6

... Volture™ be properly mounted and clamped to the vibration source. The output of the Volture should then be attached to an oscilloscope for monitoring. The output can be either the raw output of the Volture™ ...

Page 7

... The power output capability of the Volture™ products was measured in the following manner. In the cantilevered beam configuration above, the Volture was mounted to a shaker capable of generating vibrations of varying frequency and amplitude. Tip masses (four for each product) were added to alter the natural frequency of the Volture™ ...

Page 8

V20W TYPICAL PERFORMANCE POWER CHARACTERISTICS Tuned to 180 gram Tip Mass 1.8 0.250 g, Pmax=0.159 mW 0.375 g, Pmax=0.328 mW 1.6 0.500 g, Pmax=0.606 mW 1.000 g, Pmax=1.719 mW 1.4 1.2 1 0.8 0.6 0.4 0.2 0 ...

Page 9

V25W TYPICAL PERFORMANCE POWER CHARACTERISTICS Tuned to 120 gram Tip Mass 1.6 0.250 g, Pmax=0.123 mW 0.375 g, Pmax=0.276 mW 1.4 0.500 g, Pmax=0.471 mW 1.000 g, Pmax=1.468 mW 1.2 1 0.8 0.6 0.4 0.2 0 -0.2 ...

Page 10

... Pmax=0.114 mW 0.375 g, Pmax=0.248 mW 1.2 0.500 g, Pmax=0.379 mW 1.000 g, Pmax=1.311 mW 1 0.8 0.6 0.4 0 Operating Voltage V21B RELATION BETWEEN TIP MASS & NATURAL FREQUENCY 260 240 220 200 180 160 140 120 100 Tip Mass (grams) Tuned to 175 Hz 0.7 0.6 ...

Page 11

... Tip Mass 1.6 0.250 g, Pmax=0.157 mW 0.375 g, Pmax=0.323 mW 1.4 0.500 g, Pmax=0.525 mW 1.000 g, Pmax=1.484 mW 1.2 1 0.8 0.6 0.4 0 Operating Voltage V21BL RELATION BETWEEN TIP MASS & NATURAL FREQUENCY 130 120 110 100 Tip Mass (grams) Tuned 0.6 0.5 0.4 ...

Page 12

V22B TYPICAL PERFORMANCE POWER CHARACTERISTICS Tuned to 240 gram Tip Mass 0.06 0.25 g, Pmax= 0.00 mW 0.375 g, Pmax= 0.01 mW 0.05 0.5 g, Pmax= 0.01 mW 1.0 g, Pmax= 0.05 mW 0.04 0.03 0.02 0.01 ...

Page 13

V22BL TYPICAL PERFORMANCE POWER CHARACTERISTICS Tuned to 110 gram Tip Mass 0.3 0.25 g, Pmax= 0.02 mW 0.375 g, Pmax= 0.04 mW 0.25 0.5 g, Pmax= 0.07 mW 1.0 g, Pmax= 0.21 mW 0.2 0.15 0.1 0.05 ...

Page 14

... Shot Sensors and Low Vibration Levels It is often difficult to make use of low-voltage energy scavenging sources, such as piezo energy harvesters at low vibration amplitudes, solar cells in overcast or indoor environments, or Seebeck devices, etc., as most microcontrollers and sensors require minimum voltages of 1.8V or greater to operate. Using these ...

Page 15

... In this case, the measurement frequency is variable and depends on the vibration amplitude. To operate the sensor directly from the boost circuit requires: Estimation (or measurement of) the run-time and power consumption of your application within its ...

Page 16

APPLICATIONS INFORMATION - these cases, the application can use V interrupt source in addition to power source, with a rising or falling edge triggering the desired action. Discharge Interval vs. Acceleration Volture V20W @ 60Hz, 100uF ...

Page 17

APPLICATIONS INFORMATION - Tek Stop 3 Ch1 500mV Ch2 500mV Ch3 500mV M 2.00 s Figure 5: Rectified input (aqua), V CAP output (violet) from initial start-up to stable output, 10K resistive load. SWITCHED CAPACITOR BOOST CIRCUIT Tek Stop : ...

Page 18

... The circuit of Figure 2 provides a simple but effective approach to meeting these goals. The main components are a bridge rectifier formed by D1-D4, low-power comparator (U1) and buck converter (U2). During vibration, main storage capacitor C1 slowly charges until its voltage reaches the operating point (V converter U2 is enabled once the stored voltage exceeds this value plus a small hysteresis ...

Page 19

... This combination of factors helps prevent excessive mechanical damping of the beam, allowing usable output voltages to be output at lower vibration amplitudes while the piezo beam is driven near its mechanical resonance. U2 provides a regulated output voltage determined by the ratio of R7 and R8 ...

Page 20

APPLICATIONS INFORMATION - Considerations for Conversion Efficiency Converter efficiency is defined as the output power divided by the input power times 100%. The losses from the circuit’s front-end components (leakage across the storage capacitor, comparator, and R1-R3) will be small ...

Page 21

... I as the inductor will tolerate without saturating. 3) Choose C1 bias voltage to be approximately ½ the open-circuit piezo voltage in its natural vibration environment. In applications with highly variable amplitudes, a trade-off must be made between efficiency at higher amplitudes and the ability to ...

Page 22

APPLICATIONS INFORMATION - as the comparator will be ON when approaching this point. Solving for R3 Vth R3 R1 Vth R2 Vth R2 VL The addition of R3 will slightly affect the actual center voltage; however, this ...

Page 23

APPLICATIONS INFORMATION - Integration with LTC3588 Charge Management IC The LTC3588 ultra low quiescent current power supply designed specifically for energy harvesting applications. The part is designed to interface directly to a piezoelectric or alternative A/C power source ...

Page 24

APPLICATIONS INFORMATION - Inductor The buck converter is optimized to work with an inductor in the range of 10uH to 100uH. 10uH is adequate for space-limited applications, but 100uH may provide greater efficiency, particularly as the ratio between input and ...