Piezoelectric 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 David A. Johnson P.E.-June, 2000
Piezoelectric Driver Finds Buzzer’s Resonant Frequency - 7-Aug-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 by Mehmet Efe Ozbek, PhD, Atilim University, Incek, Ankara, Turkey
Piezoelectric Triggered Switch - Two different switch circuits are shown. One sources current and the second sinks current. Both switches are connected to a piezo wafer. When the wafer is tapped, the switches are activated. . . Circuit by David Johnson P.E.-February, 2002
Piezoelectric Vibration Sensor Activates Switch - An inexpensive piezo device is used as a motion sensing device for this motion alarm. . . Circuit by Dave Johnson P.E.-July, 2006
Police Car Siren - This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Police Electronic Siren - The sound produced imitates the rise and fall of an American police siren. When first switched on the 10u capacitors is discharged and both transistors. __ Designed by Ron J.
Power Buzzer - How often on average do you have to call members of your family each day to tell them that dinner is ready, it’s time to leave, and the like? The person you want is usually in a different room, such as the hobby room or bedroom. A powerful buzzer in the room, combined with a
Power Loss Beeper - For some medical equipment it is important for an operator when power is lost to the machine. The beeper is powered from a 9v battery and requires the machine to have a power switch with a third set of contacts. . . Circuit by David A. Johnson P.E.-March, 1999
Power Reminder Beeper - This circuit produces a short beep once each minute. It is powered directly off the 120vac power line to remind you that a device connected to the circuit is turned on. It is simple enough to be packaged inside a small plastic box. . . Circuit by David A. Johnson P.E.-June, 2000
Powerful buzzer for use as a doorbell - How often on average do you have to call members of your family each day to tell them that dinner is ready, it’s time to leave, and the like? The person you want is usually in a different room, such as the hobby room or bedroom. A powerful buzzer in the room, combined with a pushbutton at the bottom of the stairs or in the kitchen, could be very handy in such situations __ Learning Electronics
Powerful Security Siren-Transistors based - This circuit was requested by several correspondents. Its purpose was to obtain more power than the siren circuit already available on this website (One-IC two-tones Siren) and to avoid the use of ICs. A complementary transistor pair (Q2 & Q3) is wired as a high efficiency oscillator, directly driving the loudspeaker. Q1 ensures a full charge of C2 when power is applied to the circuit __ Learning Electronics
Powerful Siren - Simple circuitry No ICs 12V Battery operation __ Contact: Flavio Dellepiane, fladello @ tin.it
Produces Beep once each Minute - This circuit produces a short beep once each minute. It is powered directly off the 120vac power line to remind you that a device connected to the circuit is turned on. It is simple enough to be packaged inside a small plastic box . . . Hobby Circuit designed by David Johnson P.E.-June, 2000
Pushbutton Activates Service Request Beeper - A single press of a pushbutton switch turns on a beeper for one second but can’t be activated again for 60 seconds.. . . Circuit by David A. Johnson P.E.-September, 2005
Really Loud 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 . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000
Remarkable R-Beeper - As configured, this continuity beeper emits a tone when the input leads are shorted together. If a resistance is placed between the leads, the tone's pitch is lowered. A 1 ohm difference is audible, and the tone stops entirely at around 150 ohms. There is no tone for semiconductor junctions, even germanium or Schottky. Short-circuit current is under 1 mA, and open-circuit voltage is about 1.5 volts, so damage to external devices is quite unlikely. __ Designed by Tom Bruhns
Remote Control Beeper - uses rf tx/rx modules with a range of about 30m. __ Contact: P. Townshend EduTek Ltd
Remote Doorbell Beeper - This circuit will activate a beeper alarm whenever the AC line voltage is less than 100vac. . . Circuit by David Johnson P.E.-July, 2006
Screamer Siren - This is a low-cost screamer circuit to add to our range of alarm modules. It has been designed to protect your valuables on a 24 hour basis. __ Contact: Collin Mitchell
Screamer Siren-Light Controlled - This circuit will produce an ear-piercing scream, depending on the amount of light being detected by the Light Dependent Resistor. __ 555-Timer
Self-Announce for Electric Gates - The electric gate in many shops, factories (not to mention cooperative apartment houses) is kept open during working hours. This circuit detects when someone traverses the gate, ringing the bell in a very peculiar way. __ Designed by Projects & Ideas from Nutchip.com
Service Request Beeper - A single press of a pushbutton switch turns on a beeper for one second but can’t be activated again for 60 seconds. . . . Hobby Circuit designed by David A. Johnson P.E.-September, 2005
Simple Circuit Blown-Fuse Indicator Sounds an Alarm - 10-Jul-08 EDN-Design Ideas A simple blown-fuse-indicator circuit sounds a buzzer and flashes an LED when a fuse blows Design by Vladimir Oleynik, Moscow, Russia
Simple Circuit electronic buzzer - This very simple circuit just uses a couple of resistors, a capacitor and the easily available 555 timer IC.
Simple Circuit fix adds door-chime repeater - 05/13/99 EDN-Design Ideas Electromechanical door chimes can enhance your home, but they are vulnerable to costly repair problems. A defective pushbutton switch or a careless visitor can maintain the chime in an energized state for a prolonged period, thereby damaging the chime. The circuit in Figure 1 prevents damage to the chime and improves the chime's effectiveness by repeating the chime strike for as long as the pushbutton remains depressed. The circuit controls both front and rear chimes. The heart of the circuit is timer IC2, which you configure as an astable multivibrator. The timing components, R1, R2, R3, and C3, provide the required pulse widths. Design by Dennis Eichenberg, Parma Heights, OH
Simple Circuit Siren - This project is built on the third section of the PC board, identified by "SIREN" and "Project 5. " You will notice the similarity between this circuit and the LED FLASHER circuit from project 2. The only differences are the LED has been removed and the 22R resistor has been replaced by a mini speaker __ Contact: Collin Mitchell
Siren (page 84) - This circuit was requested by several correspondents. Its purpose was to obtain more power than the siren circuit already available on __ Contact: Flavio Dellepiane, fladello @ tin.it
Siren 100dB - This is a very loud siren and if two or more piezo's are located in a room, the burglar does not know where the sound is coming from. __ 555-Timer
Siren Driver - Zetex Semiconductors have a siren driver IC Type ZSD100 available that is suitable for use in alarm systems for cars and model craft. With the addition of only a few components as shown in the diagram, the device produces an ear-splitting sound of 120 dB. The IC contains an a. f. rectangular-wave generator that is driven by a __ Designed by Popescu Marian
Siren Simulator - This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Snow Depth Alarm - The design of this system alerts a snowplow driver when the snow depth has exceeded four inches. A visible red LED packaged in a 10mm package is pulsed at a rate of about 50Hz with 10uS pulses. Twenty four inches away a phototransistor detects the light from the LED. The LED and the phototransistor are housed in a section of ½ inch PVC pipe, forming a waterproof seal. . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006
Sound Generator-Clicking - 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 . . . Hobby Circuit designed by David Johnson P.E.-January, 2009
Star Trek Doorbell - In the Star Trek “Next Generation” TV series, the doorbell outside the private quarters of a crew member makes a particular “beep-boop” sound. The 3v battery powered circuit below tries to simulate this sound. The circuit uses one 74HCT74 dual D flip/flop. . . Circuit by David A. Johnson P.E.-October, 2001
Star-Trek Next-Generation Doorbell - In the Star Trek “Next Generation” TV series, the doorbell outside the private quarters of a crew member makes a particular “beep-boop” sound. The 3v battery powered circuit below tries to simulate this sound. The circuit uses one 74HCT74 dual D flip/flop . . . Hobby Circuit designed by David Johnson P.E.-October, 2001
Still 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 piezo device to more than 200 volts peak to peak . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Sweeping Siren Alarm-3 volts - A while back I was challenged by a visitor to the website. He needed a very loud sweeping siren type audio sound generator powered by 3v. He tried some of the commercial sirens but they were not very loud when powered by 3v. He also said that those . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2008
Switch activated by Piezo Vibration - An inexpensive piezo wafer is used to detect vibration and when the vibration is sufficient a switch is activated . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006 |