605-00004 Parallax

Web Site: www.parallax.com Office: (916) 624-8333 Forums: forums.parallax.com Fax: (916) 624-8003 Sales: sales parallax.com Sales: (888) 512-1024 Technical: support parallax.com Tech Support: (888) 997-8267 Piezo Film Vibra Tab ( 605-00004) The Piezo Film Vibra Tab sensor consists of a flexible piezoelectric film laminated to a polymer substrate. When the sensor is bent or displaced from its neutral axis, the strain within the piezo film generates voltage, up to 70 V voltages. A microcontroller can detect this voltage, making the Vibra Tab useful as an inexpensive switch or vibration sensor. Features Two crimped contacts for mounting and electrical connections Sensitivity of 50 mV/g Generates voltage when vibrated, flicked, or bent, from 0 to 70 V Attach a small mass to decrease sensitivity and resonant frequency Application Ideas Alarm system sensor Product damage/shock detector Acceleration sensor Tap switch Example Circuit (With Clamping Diode) The circuit above allows you to start using the Vibra Tab as a switch or shock detector with a microcontroller. The 5.1 V Zener diode clamps the sensors output voltage to protect microcontrollers whose I/O pins do not have internal clamping diodes. Use this circuit with the BASIC Stamp 2 example program, below. It tests the sensor for functionality for functionality by checking for a HIGH signal when the sensor is tapped, flicked or snapped. The BASIC Stamp microcontroller, SX microcontroller and Propeller chip have internal clamping diodes and do not require the 5.1 V Zener diode in the circuit. CAUTION This device can generate voltages of ~70 volts if bent to 90. If your microcontroller does not have internal clamping/protection diodes on the I/O pins, be sure to clamp, buffer or filter the sensors output signal to keep it within acceptable voltage/current limits for your microcontrollers I/O pin. See the manufacturers datasheet for voltage output vs. tip deflection information. Copyright Parallax Inc. Piezo Film Vibra Tab ( 605-00004) v1.1 4/30/2012 Page 1 of 2 Resources and Downloads Check out the Piezo Film Vibra Tab product page for the manufacturer datasheet and example source code go to www.parallax.com and enter 605-00004 in the search field. Please see the manufacturers website to obtain a Tech Manual, which describes more example applications, use of a mass to decrease sensitivity, configurations, and information on piezoelectric film devices.