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3V supply delivers 12V p p to piezo speaker - 10/16/03 EDN-Design Ideas:
Low-profile piezoelectric speakers can provide quality sound for portable
electronic devices, but y require voltage swings greater than 8V p-p across
speaker element. Yet, most portable devices include only a low-voltage power
source,.....(design idea added 1/05) |
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741 Based Light Sensor - CdS photocell used for light/dark controlled relay
(Tony van Roon's electronic design added 5/02) |
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Amplifier compensates piezoelectric rate gyros - 12/09/99 EDN-Design
Ideas:.....(design idea added 11/05) |
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Another Very Loud Piezo Alarm Beeper - This is yet another beeper circuit that
really draws attention. It sweeps the drive frequency slightly to produce a very
annoying sound. It uses a transformer to increase the drive voltage across the
piezoelectric device to more than 200 volts peak to peak. It cranks out an ear
splitting 120db when measured at 12 inches. ….(designed by David A. Johnson) |
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AT-121 (3W) to AT-150 (2W) Converter - AT-121 3-wire to 2-wire Piezo Buzzer
Converter, AT-150….(Tony van Roon's electronic schematic / circuit added 08/09) |
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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.....
….(designed by David A. Johnson) |
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Controller Provides Multiple Alarm Driver Formats - 01/15/98 EDN-Design Ideas:
DC/DC converters for use inside the telephone handset require operation from the
high-source-impedance phone line. Additionally, the CCITT specifications call for
maximum on-hook power consumption of 25 mA. The dc/dc converter in Figure 1 is
70%-efficient at an input power of 25 mA, providing 5V at 3.4 mA. Controlled,
low-peak switch current ensures that the 48V input line experiences no excessive
voltage drops during switching.....(design idea added 06/06/06) |
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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. (circuit.....(design idea added 6/07)
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Deer Repellent (techlib) - 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…..(added 02/05) |
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Driving
Piezoelectric Actuators Apex-AN44 - Apex App Note (added 08/08/08) |
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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 idea added 04/08) |
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High Sound Output Beeper Circuit - 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. Published in Electronic Design,
Aug 5, 1993 ….(designed by David A. Johnson) |
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High voltage Amplifier Drives piezo tubes - 12/07/04 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.....(design idea added 10/05) |
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History of Piezoelectricity - (electronic design / schematic added 2/06) |
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Introduction to Piezo Tranducers - (Tony van Roon's electronic design /
schematic added 2/06) |
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Keys finder - The ear and mouth of the circuit is a piezoelectric buzzer.
Fizzling in a frequency of 3...4 KHz produced sound waves that piezoelectric
buzzer converts them to an oscillation. This oscillation passes thought C1 and
thought inverters N1...N3.The inverters along with R1 and R2, compose an amplifier
with gain 400 ! .The C8 and C9 stabilize and reduce the signal's level.….(design
added 08/08) |
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Knock Alarm (Sunil Kumar) - his 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 uses readilyavailable,
low-cost components and can also be used to safeguard motor
vehicles....(electronic Circuit / Schematic added 10/04) |
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Machine Vibration Controls 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 piezoelectric wafer.
The wafer is normally used as a sound generator. The 3v power could be tapped from
the hour meter's own lithium battery or from a separate 3v lithium battery. The
circuit only draws about 1.5uA, so a 250mA-hr battery would power the circuit for
about 10 years. Published in EDN, Jan 16, 1997 ….(designed by David A. Johnson) |
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Motion Alarm - Using a piezoelectric device, this circuit will activate a
beeper whenever the circuit is moved. It could be used as an earthquake
alarm. ….(designed by David A. Johnson) |
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Motion Alarm Using Piezoelectric Device - An inexpensive piezoelectric device
is used as a motion sensing device for this motion alarm. This circuit will
activate a beeper whenever the circuit is moved. It could be used as an
earthquake alarm. (added 7/06) ….(designed by David A. Johnson) |
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Piezo crystal monitors liquid level - 03/30/00 EDN-Design Ideas:.....(design
idea added 11/05) |
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Piezo device generates buzz beep or chime - 05/07/98 EDN-Design Ideas:
-Two common methods exist to command voice for transmission through a PCM
channel.....(design idea added 3/03) |
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Piezo device generates buzz, beep, or chime - 05/07/98 EDN-Design Ideas:
(design idea added 3/03) |
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Piezo DeviceGenerates Buzz Beep or Chime - 04/23/98 EDN-Design Ideas: (design
idea added 05/03) |
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Piezo Disk - (electronic schematic / circuit added 2/05) |
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Piezo Education/Tutorial - (Tony van Roon's electronic design / schematic
added 2/06) |
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Piezo Pickup Amplifier Circuit - AS098 Jenson Transformer Application Note
(app note 6/07) |
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Piezoelectric driver finds buzzer’s resonant frequency - 08/07/08 EDN-Design
Ideas: By driving a piezoelectric buzzer near its resonant frequency and counting
the residual oscillations, a microcontroller can find the buzzer's resonant
frequency.....(design idea added 09/08) |
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Piezoelectric Tone Generation Using the MAXQ3210 - Maxim App Note 4148
-- 2/04/2008 -- (app note add 5/08) |
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Piezoelectric transformer - If there is a need to feed very low power devices
you may resort to infrared optocouplers, solar cells, batteries or low power
transformers although the latter might be rather oversized for the intended
purpose. Eventually, with the exception of solar cells, all...(added 04/08) |
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Piezoelectric Triggered Switch - Two different switch circuits are shown.
One sources current and the second sinks current. Both switches are
connected to a piezoelectric wafer. When the wafer is tapped, the switches
are activated. (added 7/06) ….(designed by David A. Johnson) |
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Piezoelectric Vibration Sensor Activates Switch - An inexpensive piezoelectric
wafer is used to detect vibration and when the vibration is sufficient a switch is
activated. (added 7/06) ….(designed by David A. Johnson) |
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Point-contact oscillators - The principle of operation of a car hooter has
been applied to both a ceramic sounder and a loudspeaker. A break in the supply
current is caused by the vibration of the ceramic sounder plate or the speaker
membrane. You could implement similar circuits even without a transformer but the
voltage range will be limited, there...(added 03/09) |
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Remote Switch uses No Power Fiber Optic Link - 10/10/96 EDN-Design Ideas: The
heavy-duty switching device in Figure 1 counts the number of products manufactured
and rolled out of a production line per hour. The switch is useful for counting
rolling heavy objects or materials weighing one to several thousand kilograms. It
generates one pulse per.....(design idea added 3/03) |
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Shock Sensor Circuit Prevents Data Corruption - 07/04/96 EDN-Design Ideas:
Hard-disk drives for laptop and other portable applications need to withstand
significant g-force shocks when operating. A typical 1.8-in. drive writes servo
information over less than 15% of the disk's active area, which means that the
read/write head spends more than 85%.....(design idea added 3/03) |
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Ultra Low Power 32kHz Crystal Oscillator - I have used this circuit many times
when I needed a low frequency reference, which did not draw much power. With
the components show, the current from a 3v battery is less than 1.2 microamps.
….(designed by David A. Johnson) |
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Very Loud Piezoelectric Beeper Circuit - This circuit is similar to circuit
number 7, but 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 maximum efficiency. ….(designed by David A. Johnson) |
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White LED shines from piezoelectric oscillator supply - 01/10/08 EDN-Design
Ideas: A piezoelectric ceramic buzzer powers a white LED from a single
cell.....(design idea added 02/08) |
