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Change alarm beep to dog barking

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I have a KGuard dvr with audio out and would like to make the motion alarm a dog bark instead of a beep. I have a PA amplifier and speaker in the attic. Motion would warn an intruder of a dog in the house (without actually investing in a dog).

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I have a KGuard dvr with audio out and would like to make the motion alarm a dog bark instead of a beep. I have a PA amplifier and speaker in the attic. Motion would warn an intruder of a dog in the house (without actually investing in a dog).

 

Terrible idea, and here's why:

 

You setup your DVR's beep indicator each time your outside camera's motion are triggered, for simplicity sake lets say you only have a front yard and all the other three corners of your house are sealed off. You setup motion recording for that front camera and instruct your DVR to perform a BEEP noise each time the motion is detected. Then you perform some electronics modifications to the PWM pulsed beep coming out from that small piezoelectric speaker on your DVR's logic board to trigger a loud dog barking sound effect amplified by your PA speakers, you are going to have the following:

 

1. When it rains you are going to have a loud dog barking hear-able from the outside and this sound effect is going to occur randomly as motion detection gets un-trigered only to a few seconds later to get trigger, specially if its only lightly raining where its noticeable enough to trigger the motion here and then (when its pouring on the other token you are just going to have one long continuous event with the initial bark until it stops raining).

 

2. Is there too many plants outside and moving leaves from trees? Unless you took really good care at discriminating any portions where there might be leaves moving specially when its windy, you are going to get the leaves to trigger the motion detection of your DVR once every time the wind blows hard enough, that easily get translated to thousands of motion detection events per day, or in other words thousands of loud barking noises blastered off your PA speakers, lets assume that each bark trigger event is a double bark sounding noise, for example: "baw baw", what real dog will bark twice each and consecutive times, obviously the fact that the bark are going to sound so monotonous and robotic sounding exactly the same each and every time (whether its just one, two, three barks, or more) its going to give it away that the "dog" is not real, plus potentially labeling you the "weirdo" of your neighborhood for having such a sound effect sounding thousands of times through a day.

 

Well with all that said, if you still want to carry on the project of converting the beep that comes out of the DVR into a bark, here's what you will need (note, I have never done this but its totally doable):

 

1. You will need a reed switch that can be activated by the low enough pulsed voltage signal going to the DVR's piezo electric speakers.

 

1.1. Such a reed switch will have an interrupter on the output/other side that will act as an "ON" switch when the reed switch is activated and when the reed switch is deactivated (when the beep signal goes away) it will change the ON switch into the OFF default position.

 

2. You will need the "device" that causes the Dog's Barking effect, the more configurable the device is, the better it is, for example you want a dog barking sound effects device to trigger different styles of barks and different quantities of barks once activated, preferably in "Shuffle" mode in such a way that is will playback a different random bark sound once power is applied to the sound effect device. (Power is applied when the Reed Switch is set to ON position/is activated).

 

2.1 If you cannot get a dog barking sound effect device that randomly plays different styles of barks per different sessions, then you will have to make do with the model that plays the exact same sound each and every time which increases the chances of people knowing its a fake dog, or you will need to improvise with an actual MP3 players with a variation of Dog's sound effects manually imported to the MP3 player by your self. Or you can go the old school way and use a cassette "walkman", fill up the cassette with 90 minutes of a variation of dog barking sound and then you leave the walkman in play mode pressed, powered is delivered to the walkman when the Reed Switch is activated to "ON" position, the cassette begins to play and sends the audio for amplification and stops playing when the reed switch goes back to the OFF position.

 

2.2 If you use an MP3 player, you will need a model that automatically playsback an .mp3 when power its applied, or else you will have to modify the MP3 player to wire up the reed switch to the MP3's play button, when the reed switch activates, the MP3 plays a file randomly.

 

So thats what you need. Now, you will open up your DVR, take out its motherboard, solder up two thin speaker wires on the two terminals that feed the piezo electric speakers, then install the motherboard back into the DVR's case and connect the resulting ends of the two wires to a reed switch sensitive enough to get activated by just the pulsed electric buzzer going to the piezoelectric speaker.

 

Once you do this, now you have a method to turn on anything you like each time a motion event gets triggered and that reed switch gets activated to the ON position. things you can turn on thanks to this reed switch is some special lights/lamp of low wattage (read: LED), flashers, loud alarms, and of course your dog sound effect equipment.

 

In order to pull off this project, you need a good level of creativity and ingenuity, if you have that then good luck you can undertake such project with virtually zero risks of damaging the DVR's motherboard and with a high success rate of actually being successful.

 

If you need to activate a much bigger load, then the smaller reed switch will need to be connected to activate a much bigger reed switch with a bigger load capacity it can handle and then connect that bigger load to that much higher rated reed switch.

 

**you might have to create/elaborate some special circuitry depending on what you want to do. If no reed switch is activate-able from the low enough voltage signal going to the piezoelectric speaker on the DVR's motherboard, then you will need to create a small circuit to create/amplify the signal big enough for the reed switch to pick it up and activate, such a circuit will need its own power source (12v power adapter, etc)

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Or just connect a pir sensor to your dvr alarm inputs

And use a dog bark unit

Best to always keep things simple

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