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Sound Operated / Sound Activated Circuits
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Last Updated: November 22, 2021 02:42 PM

Circuits Designed by Dave Johnson, P.E. :

Audio Activated Switch -  This circuit will activate a transistor switch when it detects at least 50mv peak to peak of an audio signal.    it could be used to turn on a relay, routing the signal to were it is needed.. . . Circuit by Dave Johnson P.E.-July, 2006

Detector/Switch for Audio Signal -  For some audio systems it is desirable to have an automatic switch circuit turn on other devices, such as an amplifier, if an audio signal is detected on one line.  The hobby circuit below will activate a transistor switch when it detects at least 50mv peak to peak of an audio signal.  The switch could be used to turn on a relay, routing the signal to where it is needed.  A single 3v lithium cell will power the electronic circuit for about 5 years . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-778-8407




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

16-Way Clap-Operated Switch -  Control your home appliances without getting out of your bed.  You just have to clap in the vicinity of the microphone used in this circuit, which you can keep by the...__ Electronics Projects for You

A Voice Controlled LED Light Show using a VRStamp -  A voice controlled LED light show.  Train your board with your voice, then control the LED animation by saying commands!  This project is fitted to the mikroC RSC-4x compiler small memory model : no mikroC licence is needed, just to show the power of the demo version! __ Bruno Gavand

Add voice command to virtual instrumentation -  05/30/02 EDN Design Ideas:  Debates still persist in the engineering community about the relative merits of analog and digital controls of instrumentation.  Meanwhile, a revolutionary new type of control—voice-command control—is gaining acceptance in many application areas (Reference 1].  This design idea focuses on the practical implementation of the Voice Commander voice-command interface in a virtual-instrume Design by Alexander Bell, Infosoft International Inc, Rego Park, NY

Add voice commands to your CAD system -  05/02/02 EDN Design Ideas:  The first time I activated the Language Bar (Speech Tools] in my Microsoft Word 2002 and started dictating this Design idea, the on-screen title displayed "cat" instead of "CAD.   " By using the "Add/Delete Words" feature, I'vetrained the system to recognize the "CAD" acronym.  This was my first experience with the MOSR (Microsoft Office Speech Recognition] tool, which is part of the latest Micros Design by Alexander Bell, Infosoft International, Rego Park, NY

Alarm using Your Own Voice -  This alarm plays your prerecorded voice message.  it is built around the readily available quartz clock.  Take the buzzer out of the quartz clock and connect its positive terminal to pin...__ Electronics Projects for You

Appliance Timer-Cum-Clap Switch -  PANKAJ D.  CHOUDHURY When planning for a week-end outing to return late in the evening, we are often in an ambivalence whether to leave the staircase/outside light ‘on’ or ‘off.’ We sometimes...__ Electronics Projects for You

Audio Activated Recorder -  ScanMate connects between your scanner and tape recorders (via the recorder's microphone or auxiliary input and its remote start jack). __ Designed by Tony van Roon  VA3AVR

Audio Activated Switch -  This circuit will activate a transistor switch when it detects at least 50mv peak to peak of an audio signal.    it could be used to turn on a relay, routing the signal to were it is needed.. . . Circuit by Dave Johnson P.E.-July, 2006

Audio Controlled Christmas Lights -  Here is a simple circuit to control 110VAC things such as Christmas Lights with low voltage audio.  Be careful, high voltage AC can kill you.    The basic idea was to have Christmas lights flash with the music.  in my design I use an ordinary amplified computer speaker, a diode bridge, and a ‘CRYDOM’ SSR (Solid State Relay).  in order to increase the time that the lights were on as well as protect the SSR I used a Diode Bridge to rectify the signal from the amplifier circuit.   __ Designed by Written byAlan Parekh

Audio-Controlled Running Light -  This mains-operated audio-controlled running light can be used in discotheques.  The lamps glow in running sequence as per the sound of music.  Of the ten AC lamps, only one lamp permanently...__ Electronics Projects for You

Build a Voice-Activated Relay (VOX) -  Triggers devices on and off with sound.__ SiliconChip

Cheap Sound Sensor for AVR -  I searched the web for a cheap method to let the ATmega respond to sound.  My knowledge in analog circuits is very limited, but what I do remember, is that you can not attach a electret mircophone to a controller pin.  The signal of __ Designed by Alexander Weber

Clap Activated Remote -  in infra-red or wireless remote control has the disadvantage that the small, handy, remote transmitter is often misplaced.  The sound operated switch has the advantage that the transmitter is always with you.  This project offers a way to control up to four latching switches with two claps of your hand.  These switches may be used to control lights or fans ? or anything else that does not produce too loud a sound.__ 

Clap On / Off Switch -  Clap On / Off Switch Diagram This is the circuit diagram of Clap On / Off Switch.  The circuit allows you to operate your lighting or any circuit device which use 24V / 3A maximum supply, simply by clapping your hands. it has a relay output that can be used to turn external devices on/off.  This__ 

Clap Relay -  Clap sensitive on-off Relay.3V Battery operated, small portable unit,  __ Contact Flavio Dellepiane, fladello @ tin.it

Clap Remote -  An infra-red or wireless remote control has the disadvantage that the small, handy, remote (transmitter) is often misplaced.  The sound operated switch has the advantage that the transmitter is always with...__ Electronics Projects for You

Clap Sound Light Switch -  This box is a 40Khz ultra-sound detector, with a latch and an output relay, when you clap your hands, the relay turn the light on, when you clap again the light goes off.  The 3 holes was LEDs, showing ON or OFF state, and ultra-sound level, The 3 LED is floting arround inside the box, I did not glue them enough :-) A potentiometer is used to adjust the sensitivity. __ Designed by Thomas Scherrer OZ2CPU

Clap Switch -  Here’s a clap switch free from false triggering.  To turn on/off any appliance, you just have to clap twice.  The circuit changes its output state only when you clap twice within...__ Electronics Projects for You

Clap Switch -  A clap switch circuit is a classic beginner’s project.  Equipment can be switched on and off by just clapping your hands.  Add a tiny microcontroller and you can easily build-in some more useful features.  The microcontroller in this circuit makes it a simple job to add some useful features that are not seen on other clap switch __ Designed by Popescu Marian

Clap Switch Circuit -  This is a simple clap switch circuit with high sensitivity.  The only unusual component is the single coil latching relay.  While there are numerous means of generating the latching function, the latching relay greatly simplifies the circuit and provides a relay contact interface for driving a 115 or 230VAC load such as a light bulb.__ 

Clap Switch Diagram -  Here’s a clap switch free from false triggering.  To turn on/off any appliance, you just have to clap twice.  The circuit changes its output state only when you clap twice within the set time period.  Here, you’ve to clap within 3 seconds.  The clap sound sensed by condenser microphone is amplified by transistor T1.  The__ 

Clap-Based Digital Volume Control -  This clap-based digital volume control offers four levels of volume control.  With each clap, the volume of the audio system increases.  After the fourth clap, the level of volume returns to...__ Electronics Projects for You

Clap-Operated Electronic Switch -  Here’s a simple clap-operated electronic switch.  Using this switch, you can turn on any appliance by clapping five times and turn it off by a single clap.  The switch activates the...__ Electronics Projects for You

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.

Detector/Switch for Audio Signal -  For some audio systems it is desirable to have an automatic switch circuit turn on other devices, such as an amplifier, if an audio signal is detected on one line.  The hobby circuit below will activate a transistor switch when it detects at least 50mv peak to peak of an audio signal.  The switch could be used to turn on a relay, routing the signal to where it is needed.  A single 3v lithium cell will power the electronic circuit for about 5 years . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Dog Whistle -  it's well known that many animals are particularly sensitive to high-frequency sounds that humans can't hear.  Many commercial pest repellers based on this principle are available, most of them operating in the range of 30 to 50 kHz.   __ Designed by Tomaz Lazar-Ljubljana, Slovenia

LED Musicolour: Light Up Your Music, Pt.1 -  Now you can have a kaleidoscope of colour which continually changes in time to music.  This consists of 16 strings of LEDs which are individually controlled by 16 frequency bands.  Louder signals in each of those bands means that the respective LED string will be brighter.  Use it for a Christmas light show, a disco or just for fun when playing music.__ SiliconChip

LED Musicolour: Light Up Your Music, Pt.2 -  The new LED Musicolour makes building a spectacular light and music show easier than ever.  in this second and final instalment, we explain how to build and test the unit and also detail how you can control it.__ SiliconChip

Microcontroller Clapper Switch -  introduction I always thought the clapper so cool.  For those who are lazy like me, turn on or off the bedroom light without getting out of bed, simple clap your hands is amazing.  Thinking about it I projected one for me.  Several __ Designed by Toddy Cangica

Night Alert -  idea of this circuit came to me a midnight when my pet dog started barking continuously on sensing a moving shadow, perhaps that of an intruder.  Dogs have a night adaptation capability to maximise the sensitivity of vision in low light.  They are well adapted to see moving objects rather than stationary ones in darkness.    This circuit turns a lamp ‘on’ for a short duration when the dog barks, giving an impression that the occupants have been alerted.__ Electronics Projects for You

Perimeter Monitor -  Using a single cable such as speaker wire or doorbell cable, this circuit can be remotely positioned, for example, at the bottom of a garden or garage, and used to detect all sound in that area.  The cable can be buried in a hosepipe or duct and is concealed out of sight.  The mic is an ordinary dynamic mic insert __ Designed by Andy Collison

Room Sound Monitor -  With this simple circuit, you can secretly listen to conversations going on in a room.  The circuit is very sensitive and powered by a 3V battery.  The working of the circuit is...__ Electronics Projects for You

Got Designs?
Please eMail
if you want me to link to and/or post your original design Thanks.


Sound Operated / Sound Activated Circuits#'s - R     S - Z


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