Beeper & Buzzer Circuits, page 1

Beeper & Buzzer Circuits Page 1
Beepers & Buzzers: #-B C-D E-O P-R S-Z
Last Updated on: Friday, March 23, 2012 04:29 PM

Circuits Designed by Dave Johnson, P.E. :

24V DC Powered Beeper with 4 Separate Inputs
24v DC is a very popular voltage used in industrial settings. The circuit below was designed to accept four different 24v DC alarm input signals, which are then used to drive a single low power beeper. The beeper is a magnetic type with its own oscillator/driver. The four diodes form an “OR” gate so any one of the four inputs will cause the beeper to make noise. A CMOS version of the popular 555 timer is used to strobe the beeper on and off at about 1Hz.

3V Sweeping Siren Alarm
The circuit uses a LTC1799 precision frequency generator from Linear Technology. A 74HC14 hex Schmitt trigger from Texas Instruments is also used to perform several other functions. One section is wired as a simple 7Hz square wave oscillator....

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.

BASEMENT DOORBELL BEEPER
If you can't hear your doorbell when you are in your basement try this circuit. This circuit takes advantage of the 24vac power source located near the furnace. Using a simple current transformer technique, the circuit sounds a beeper whenever the main door chime is activated.

Basement Doorbell
This circuit will activate a beeper in the basement, whenever the front doorbell is pressed.

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

24V DC Powered Beeper with 4 Separate Inputs - 24v DC is a very popular voltage used in industrial settings. The circuit below was designed to accept four different 24v DC alarm input signals, which are then used to drive a single low power beeper. The beeper is a magnetic type with its own oscillator/driver..... [Hobby Corner Circuit by Dave Johnson]

3V Sweeping Siren Alarm - The circuit uses a LTC1799 precision frequency generator from Linear Technology. A 74HC14 hex Schmitt trigger from Texas Instruments is also used to perform several other functions. One section is wired as a simple 7Hz square wave oscillator.… …. [Hobby Corner Circuit by Dave Johnson]

555 Tone Generator 8 Ohm Speaker - This is a basic 555 squarewave oscillator used to produce a 1 Khz tone from an 8 ohm speaker. In the circuit on the left, the speaker is isolated from the oscillator by the NPN medium power transistor which also provides more current than can be obtained directly from the 555 (limit = 200 mA). A small capacitor is used at the transistor.... [Circuit designed by Bill Bowden]

A simple electronic buzzer - This very simple circuit just uses a couple of resistors, a capacitor and the easily available 555 timer IC. The 555 is setup as an astable multivibrator operating at a frequency of about 1kHz that produces a shrill noise when switched on. The frequency can be changed by varying the 10K resistor.... [Radioland.nt.au]

American Police Car Siren (linscott) - Scroll down to locate this circuit. The 555 on the right is wired as an alarm tone generator and the second 555 timer on the left is wired as a low frequency astable timer which generates a ramp waveform of about 6 seconds that is buffered by the transistor and again used to frequency modulate the tone generator. The transistor is used to help strengthen the signal to the speaker....(electronic design added 08/08/08)

AN16 Automotive & Household Siren Driver Circuits: Zsd100 & Discrete 'H'-Bridge Minimum Parts Count Solution - Zetec Semiconductors Applications Notes A solution is provided that uses a minimum number of components by utilizing an application specific signal generation IC, and a high efficiency 'H'-bridge effected with 3A DC rated Super-δ TO92 style switching transistors. (app note added 2/06)

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]

Assortment of Siren Circuits - several circuits here, spend some time and view each of them

Audio MilliVoltmeter - For Testing Amplifiers (etc), An analogue design, 3mV to 30V with dB scale (schematic / Circuit design added 9/02)

Automotive & Household Siren Driver Circuits: Zsd100 & Discrete 'H'-Bridge Minimum Parts Count Solution - Zetec Semiconductors Applications Notes A solution is provided that uses a minimum number of components by utilizing an application specific signal generation IC, and a high efficiency 'H'-bridge effected with 3A DC rated Super-δ TO92 style switching transistors. (app note added 2/06)

Basement Doorbell - This circuit will activate a beeper in the basement, whenever the front doorbell is pressed.... [Designed by David A. Johnson]

Basement Doorbell Beeper - If you can't hear your doorbell when you are in your basement try this circuit. This circuit takes advantage of the 24vac power source located near the furnace. Using a simple current transformer technique, the circuit sounds a beeper whenever the main door chime is activated. …. [Hobby Corner Circuit by Dave Johnson]

Battery Low Voltage Beeper - This circuit provides an audible and visual low voltage warning for 12V battery powered devices. Idle current: 6ma Low Voltage Warning current: 15ma…. [Circuit designed by Forrest Cook]

Beeper Bug This bug can be attached to anything from a glider to a plant and you can track it with a radio. Why track a plant? The Beeper is the result of many requests for a mini tracking device and introduces a new world of tracking….(circuit added 09/09/09)

Bells Ring Generator - Three circuit options. Can be synchronized to Christmas tree flashing lights. (electronic circuit added 09/04)

Birdie Doorbell Ringer - P1 is of experimental value. Start with 220 Ohms or so and modify to suit your needs. The transistor is a general purpose kind and is not critical, almost any PNP type will work. L1 is a bell-transformer which is usually already present in the house. If you wish, you could use a battery instead of the bell transformer. Just hookup a 9-volt battery (or wall adapter)to points 'A' and 'B' (A=+) the diode (D1) is to protect the circuit from accidental polarity reversal and is optional, but required as a rectifier for use with the bell transformer.…. [Tony van Roon's circuit]

British Police Car Siren - The first circuit simulates the siren of a British police car. It uses two 555 timers in the circuit. The 555 on the right is wired as an alarm tone generator and the second 555 timer on the left is a 1 Hz astable multivibrater....(electronic design added 08/08/08)

Beepers & Buzzers: #-B C-D E-O P-R S-Z