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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.
555 Tone Generator 8 Ohm Speaker - This is a basic 555
square wave 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..
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.
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.
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.
Assortment of Siren Circuits
Audio MilliVoltmeter - For Testing Amplifiers (etc), An
analogue design, 3mV to 30V with dB scale
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.
Basement Doorbell - This circuit will activate a beeper
in the basement, whenever the front doorbell is pressed.
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.
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…
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…
Bells Ring Generator - Three circuit options. Can be
synchronized to Christmas tree flashing lights.
Birdie Doorbell Ringer
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 multivibrator.
Buzzer
Check Engine Beeper - When wired into a car’s indicator
light panel, this circuit will turn on a loud beeper when
the “check engine” light turns on.
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..
Continuity Buzzer is Frugal with Power - EDN-Design
Ideas: [Note: File contains multiple circuits. Scroll to
find this one] The continuity detector in Figure 1 is based
on W Dijkstra's "Fleapower circuit detects short circuits" (EDN,
July 2, 98, pg 122). The buzzer indicator allows you to
devote full attention to making the connection without
having to observe an LED. The circuit also consumes less.
Controller Provides Multiple Alarm Driver Formats - 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.
Counter with Doorbell
Cuckoo sound Generator - This circuit generates a
two-tone effect very much alike the cuckoo sound. It can be
used for door-bells or other purposes thanks to a built-in
audio amplifier and loudspeaker. Used as a sound effect
generator it can be connected to external amplifiers, tape
recorders etc. In this case, the built-in audio amplifier
and loudspeaker may be omitted and the output taken from C8
and ground.
Curious C Beeper - The Curious C-Beeper uses the
two-transistor flasher in conjunction with a darlington
transistor to make a most unusual capacitance beeper probe.
When a capacitor is touched to the probe, the probe beeps at
a frequency that varies with capacitance.
Destroyer Whooper Alarm - If you've ever watched any TV
at all and seen those old WWII navy movies, you've heard
that distinctive "whoop-whoop-whoop" as a destroyer sliced
through the waves, guns blazing, and everybody yelling
"battle stations!"..
DIN Audio Pinouts
Ding-Dong Bell
Door chime Privacy Sentry ATtiny12 - An ATtiny12
controller as a timer and some switching circuitry turns the
doorbell off for 10 hours at the same time each day….
Door Knock Beeper - In some apartment buildings and
homes, not equipped with a door bell, it may be hard to hear
someone knocking on the front door. The circuit below
provides a means to activate a loud beeping sound inside,
whenever someone knocks on the door from the outside. The
circuit is powered by a 9v battery, which should provide
years of service. An on/off switch allows the device to be
turned off if desired.
Doorbell for the Deaf (Andy Collinson) - This circuit
provides a delayed visual indication when a door bell switch
is pressed. In addition, a DPDT switch can be moved from
within the house which will light a lamp in the door bell
switch. The lamp can illuminate the words "Please Wait" for
anyone with walking difficulties..
Doorbell Indicator-Remote
Doorbell with Counter |
