Eavesdropping, stalking, and noise harassment via technology

So, a motion detecting camera happens to be able to capture 4 or 5 seconds of action leading upto an event that you want recorded and preserved.

Trouble is, the triggering event is actually a noise.

Problem supposedly solved by using a simple sound-activated toy that will move around in front of the motion detect camera once the toy "hears" the noise.

Trouble with that ends up being two fold: one, the 260 type micro DC motor the toy uses is much too loud (while also employing a noisy and messy spinning off-balance wobbling action). And, the bigger problem is that the "motion detect" camera actually only detects warm things moving around using a PIR (Passive InfraRed) sensor.

So, pull out the DC motor and figure some way to quietly move an IR emitter using the power that was originally used to run the motor.

An electromagnet pulling a IR LED might work.

But, a simple wire coil could be treated like a short circuit, since there is chance that the coil has less resistance than the motor. And, there is no documentation on the micro DC motor.

So, now calculate the resistance for the motor, and attempt to hand make an electromagnet coil having the same resistance that the micro DC motor had. Apparently more coils means more resistance. Use the ohms setting on the multimeter/voltmeter to test that the coil has appropriate resistance.

Ultimately, an arrangement where the electromagnet successfully moves an IR source is desired. If IR is provided by an IR LED, powering that LED must be accounted for. The sound-activated toy currently has two red LED lights it uses for "spooky eyes". Use this circuitry for at least one IR LED. Take care to match voltage, and amperage requirements. And don't forget diodes do have a particular direction in a circuit (positive and negative polarity).

As an aside, there is some small chance that the handmade electromagnet could generate enough heat to make its own infrared signature. So that should be determined first.

Once its understood what kind of heat generator will work, figuring an "electromagnetic means" to move it across the camera's field of view is next.

Pendulum arrangement uses gravity to put it back into its initial position.

A "Cavendish" arrangement is much less heavy, but would require a light spring to put it back into the initial position once power ends for a given cycle.

Stuff I found online regarding all this:

1. Circuit sees wire coil as a low resistance short:

electronics.stackexchange.com/questions/185024/power-supply-sees-electromagnet-as-a-short-circuit

2. How to determine amperage for an undocumented resident, I mean undocumented dc motor:



3. Calculate resistance using ohm's law:

www.wikihow.com/Calculate-Total-Resistance-in-Circuits#:~:text=If%20you%20know%20the%20total

4. Voltage determined using a voltmeter across the leads that previously supplied power to the micro DC motor.

5. Torsion bar layout used by Cavendish:

en.wikipedia.org/wiki/Cavendish_experiment#The_experiment

The motor squealing at 5,000 to 10,000 RPMs is about as bad as the gear box. Yes there is a gear box.

No idea how you mean a highly spinning motor axle produces anything like a pendulum. Or "release an LED to act like a pendulum". First, what's that? How does it get reset for the next round? I'm much confused here!

I see a set of wires meant for an LED getting twisted up into the motor axle that way, unless you clearly outline what you mean with that.

The load and impedance part is a new concern, though.

Thanks for the heads up.

10,000 RPMs for a solid minute as the circuit and motor do creates minced meat of any of that, there's what means to reset it back to top? Unwind then wind once its past a certain point? That would be hard. And, as I say, the motor is too loud.

Furthermore, this is DC not AC...



So, I see no need to discuss or confuse impedance.

I'm making something automatic. There are as many as 20 sound events to capture each day, and ReoLink could make video and audio clips of them all, and have them in decent edited form, stored away for me automatically too, if I get this right.

So, I'm not rewinding string 20 times. Especially, when I may not realize it needs rewinding in certain instances.

There might be some way to make a loop where the IR LED traces out some kind of circular path, one where the plane of the LED remains oriented with the horizon, such that the wires don't wind up.

But, rather than doing that... because I don't like the sound of a motor atop the noise event I'm trying to automatically capture... competing with what I'm trying to capture in any case... and because I also think the speed of the motor without "noisy step down gears" is just too fast...

I'll use Cavendish's arrangement, but just ever so slightly tilted. So as to incorporate elements of both his layout and that of a pendulum. This way I don't really need a spring like I originally thought regarding Cavendish's.

The "torsion bar" in my arrangement (carrying the LED) will have the tendency to drift away from the electromagnet when the power goes off. Something the way that a refrigerator door tends to drift closed on its own because it was hung that way; using gravity to encourage it along.

Once power is on, the electromagnet will pull the IR LED uphill until it rests against the magnet. As the LED is drawn up toward the magnet it will trace out a moving heat signal for ReoLink, such that Reolink awakens and makes and stores an edited video/audio clip.

A clip that has the moments leading upto the noise, the noise, and the moments after.

way outside my competence.

And, the most recent workaround:

Just use the meager 10 volts, 1 amp to power some sort of switch, such switch staying open for the 25 seconds that the toy circuit provides.

I was meaning to include an AC to DC adapter that would power the toy circuit instead of batteries. So, the AC outlet could also be used to power a more serious electromagnet.

The switch would stay open for 25 seconds and the coil, powered by AC would also stay energized for those 25 seconds.

I see no other option if I want a reasonably silent electromagnetic coil doing the grunt work of moving that IR LED around.

If possible, any other suggestions involving getting that coil to do something useful would be appreciated.

The problem in my situation is that on a recording, having one of their "Twack" noises immediately followed by the toy making ANY noise at all can be easily interpreted that both noises came from the toy. In fact, even if the toy is totally quiet, the sound happening and then the toy immediately starts moving might also come off like it's all about what the toy is doing, all of it.

But, in my opinion, two noises right agaisnt one another is just too problematic. Better that there is a noise (that I'll have to argue is elsewhere in the background) and then the toy is seen immediately moving.


The micro DC motor and its gearbox is definitely, DEFINITELY a sound issue, though. Because the toy's wobbling motion noise is close enough to the microphone, and the two sounds are so close together that, on the recording, there is no "Twack" to be heard, even though it's there.

You mention a keystone, fundamental part of the argument used to defend those who I think are involved: "eh, the building makes noises".

And, I know it does. In my 12 hour long videos that I cull through currently, I occasionally hear those building noises. They are located off to the west edge of the building when the sun beats on that side of the building. Winter, summer, fall, spring, it is there.

And, specifically to what you mention about relays, I know my freezer and refrigerator both have switches that make distinct Pop! sounds. The sunlight noises are "Frumph", the switches are "Pop". This noise, however is "Twack!" All distinct on the recordings.

(More of a Twack rather than Thwack. It's sharp and distinct in the recordings, I think. At least they are all distinct to me at this point. I'm very familiar with them all by now, and where they emanate.)

Anyway -

The problem accepting "building noises" are what's happening to wake me are two fold:

The first half year I lived here, whatever common building noises there are didn't wake me. In fact that period involved incredibly peaceful slumber. So, the sunlight noises and refrigerator switches aren't really anywhere close to the intensity of these "Twack!"s.

Juanita Brown who lived here before me in another condo next to mine called the police so repeatedly about new, unusual thumping sounds that the police remembered her when I spoke to them. She had lived here for many years. Only toward the end of her stay here did she start to report unusual thumps.

The argument for further defense was that Juanita was suffering dementia. So, we should apparently just accept people who suffer dementia cannot describe anything correctly. Everything coming out of the mouth of a dementia patient in regard to describing their surroundings is inaccurate. They are apparently in a constant and perpetual state of error.

This technology could be repurposed such that a needle normally used to identify a given electric value could, instead, carry an IR emitter.

Thereby quietly moving a source of heat through the ReoLink camera field of view.