Beeper that is Very Loud- This circuit generates a continuous tone instead of a pulsing one. The circuit delivers about 110db ( 12 inches away) from a 9v battery using a single inexpensive C-MOS IC. An off-the-shelf piezoelectric beeping device is driven at resonance to insure maxim. . . Circuit by Dave Johnson P.E.-June, 2000 Boost Voltage to Piezoelectric Transducers- 06/09/11 EDN Design Ideas: Drive a piezo device at maximum power and its resonant frequency. Piezoelectric transducers are common in ultrasonic and acoustic-alarm-signaling applications. To get enough acoustic power from a piezoelectric transducer, you must power the device with a frequency at or near its resonant frequency. Furthermore, the driving voltage should be as high as the transducer allows. Design by Kurt Nell, Sankt Pölten, Austria
Click Sound Generator- Often in computer controlled systems, you would like to generate a “click” sound whenever a button is pressed. This provides the user with audible feedback that the pushbutton press has been acknowledged. The two circuits below generate such a sound. A click sound is generated each time the logic input swings from a logic low to high condition. . . Circuit by David A. Johnson P.E.-January, 2009
Controller provides multiple alarm-driver formats- 01/15/98 EDN Design Ideas: Using a piezoelectric element for alarm applications offers low cost, low power, and flexibility. By coupling this element with a 12C508 programmable controller (Microchip Technology, Chandler, AZ], you can implement an eight-pin alarm generator. This approach provide as multiple driver formats with a minimum of additional cost and footprint Design by William Grill, Riverhead Systems, Littleton, CO
Current-mode instrumentation Amplifier enhances piezoelectric accelerometer- 11/23/06 EDN Design Ideas: Circuit suppresses capacitively coupled noise pickup by piezoelectric sensor and its wiring Design by Dave Wuchinich, Modal Mechanics, Yonkers, NY
Deer Repellent- Here is a simple sensor which can detect the seismic vibrations caused by a person or large animal walking nearby. A representative application for the sensor is a deer repellent for the vegetable garden __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Finger Tap Piezo Relay- This circuit uses a flat piezo wafer, glued inside a plastic box, as a finger tap sensor. With each tap of a finger to the box holding the wafer, the circuit turns on and off AC or DC power to an external device. The circuit is powered by a 9v battery . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2010
Harvest Energy using a Piezoelectric Buzzer- 03/20/08 EDN Design Ideas: You can harvest small amounts of mechanical energy using a piezoelectric buzzer to charge a supercapacitor Design by Carlos Cossio, Santander, Spain
High Sound Output Beeper- I you need a real loud beeper, this circuit delivers about 110db ( 12 inches away) from a 9v battery using a single inexpensive C-MOS IC. An off-the-shelf piezoelectric beeping device is driven at resonance to insure maximum efficiency. By changing the control IC to a 74AC14, the same circuit can operate from 3v and 1.5v batteries. . . Circuit by David Johnson P.E.-June, 2000
High-voltage Amplifier drives piezo tubes- 7-Dec-04 EDN Design Ideas: Piezoelectric tubular positioners that drive manipulators in scanning tunneling microscopes require high-voltage, low-current drive circuits. The circuit in Figure 1 can drive high-resistance, low-capacitance piezoelectric loads at a -3-dB bandwidth of 6 kHz. It offers a low-cost alternative to commercial drivers. PDF has several circuits, please scroll to find this one Design by Bipin Duggal, Netaji Subhas Institute of Technology, New Delhi, India
History of Piezoelectricity- 19-Feb-09 EDN Design Ideas: A voltage-to-frequency converter uses square roots to extend dynamic range by orders of magnitude__
Hour Meter triggered by Machine Vibration- This hobby circuit allows an off-the-shelf battery powered digital hour meter to be turned on and off, according to a machine's operation, without requiring a direct electrical connection to the machine . . . Hobby Circuit designed by David A. Johnson P.E.-January, 1998
Improved Solar Path Light- The circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance. I suggest using a quality 10 cell solar panel with at least a 4 square inch area. Buy a panel with solar panels that fills . . . Hobby Circuit designed by Dave Johnson P.E.-March, 2011
Keys Finder- The ear and mouth of the circuit is a piezoelectric buzzer. Fizzling in a frequency of 34 KHz produced sound waves that piezoelectric buzzer converts them to an oscillation. This oscillation passes thought C1 and thought inverters N1N3. The inverters along with R1 and R2, compose an amplifier with gain 400 !. The C8 and C9 stabilize and reduce the signal's level. __
Knock Alarm- This circuit ( Fig.1) , used in conjunction with a thin piezoelectric plate, senses the vibration generated on knocking a surface ( such as a door or a table) to activate the alarm. It...__ Electronics Projects for You
Knock Alarm- This circuit uses a thin piezoelectric sensor to sense the vibrations generated by knocking on a surface; e.g., a door or table. Basically, it amplifies and processes the signal from the sensor and sounds an alarm for a preset period. In operation, the piezoelectric sensor converts mechanical vibration into an electrical signal. This sensor can be attached to a door, a cash box, cupboard, etc using adhesive. __ Raj. K. Gorkhali c Silicon Chip Electronics
Machine Vibration Triggers Hour Meter- This circuit allows an off-the-shelf battery powered digital hour meter to be turned on and off, according to a machine's operation, without requiring a direct electrical connection to the machine. Machine vibrations are detected by an off-the-shelf piezo. . . Circuit by David A. Johnson P.E.-January, 1998
Microcontroller Drives Piezoelectric Buzzer At High Voltage- 03/01/12 EDN Design Ideas: Drive the buzzer directly from the μC’s I/O pins. Piezoelectric buzzers find wide use in embedded systems for audible-signal generation. You can drive a piezoelectric element directly from a microcontroller’s I/O pins, but the maximum voltage rating and loudness of a piezoelectric buzzer are typically several times larger than the voltage an I/O pin supplies. Using four enhancement-mode MOSFETs that connect in an H-bridge configuration, the microcontroller can drive the buzzer at a high alternating voltage. The gate terminals of the N-channel transistors in the lower arms of the bridge can connect directly to the microcontroller’s I/O pins. The voltage level on the I/O pins is insufficient for switching the P-channel transistors, however. Design by Mehmet Efe Ozbek, PhD, Atilim University, Ankara, Turkey
Microcontroller Drives Piezoelectric Buzzer At High Voltage through One Pin- 08/17/12 EDN Design Ideas: If you're short on I/O pins, this circuit might solve your problem. Design by Mehmet Efe Ozbek, PhD, Atilim University, Ankara, Turkey
Motion Alarm using piezo Device- An inexpensive piezoelectric device is used as a motion sensing device for this motion alarm. . . Circuit by David A. Johnson P.E.-July, 2006 |