Electret Power Supply

[@bchoward0000]

"And as someone who has electronics skills, I happen to be able to do something with that kind of spite." I fucking love it.

[@RubberBanned]

You are great. These make what I don’t know how to do pretty approachable.

[@h7opolo]

finally, someone talking about microphone energy harvesting.

[@funksterdotorg]

Back inna day some camcorders would say "plug in power" next to the mic jack to indicate that they would provide power to the mic. Maybe someone decided that that wasn't cool any more. Stereo version just needs two resistors and a supply that's stiff enough to not be (significantly) moved by the AC current coming back through the resistors. Yes you'll always get a little bit of cross-coupling but you can work out how much it'll be if you know the characteristics of the signal and the components, and you don't need very much separation for a pair of mics that are 25mm apart.

[@a54dumb]

I used that technique to connect the optical pickup of a 16 millimeter movie projector to the “plug-in” power external stereo microphone jack on my Sony mini-DV camcorder. Surprisingly, the audio level from the projector optical pick-up matches nicely with the mic. input audio level on the camcorder. The projector audio is mono, so I simply connected the left and right together where the projector audio feeds in. The whole thing fits into a small metal project box and I refer to it as an “electret phantom power blocker.”

[@concr3t3]

Thank you for the adorable "Mighty Might Bosstones" reference, sincere lol

[@OkSharkey]

Oh hey, 21:30 helped me understand what went wrong with an audio buffer I built recently, wasn't expecting to find an answer to that today, amazing, thank you

[@time-lapserpro4370]

THANK YOU! That's what that click is, after a ton of searching to find nothing useful I just figured it was the DAC freaking out after monetarily shorting one of the channels to ground or something. You do a great job at bringing surprisingly obscure information to the surface.

[@nickwallette6201]

This can be caused by other things as well, like when the amplifier circuit in the headphone output is powered by a single-rail DC power supply. Since audio is AC and swings above and below the 0V reference point, you can't power an audio amp directly from 0V and +5V/12V/etc.. You need a negative reference as well. One simple way to do that, when all you have is a single positive rail, is to divide it in half and make the 50% point the new "0V" reference, so you have -50% and +50% relative to that point. The output is then AC-coupled through a capacitor to block the DC voltage relative to the "real" ground. The problem is, the output side of that capacitor is essentially floating in nowhere-land relative to DC ground, since the only connection (with nothing plugged in) to ground is through a component that blocks DC. When you plug in a pair of headphones, there is suddenly a path to ground, and the entire system stabilizes its DC bias point. This can cause a pop while the capacitor charges or discharges through the load, and then settles. Similar thing happens when you first power-up a single-rail DC supply audio circuit. The "virtual ground" point goes from 0% to 50%, typically at a higher speed than the lowest passable frequency of the output coupling capacitor, causing a very low frequency, and sometimes high amplitude, WHOMP. (Common example: Turn on your computer with speakers connected to the sound card.) It _can_ happen in AC amplifiers too, while all of the transistors find equilibrium, but the severity depends a lot on the topology of the circuit and its behavior while the rails are diverging from 0V.

[@EilonwyWanderer]

Spite, what a powerful motivator! Sorry it was a shitty day for you; grateful that it prompted such a cool video.

[@AttemptingAstro]

For real about not being available. I built a 4-port electret phantom power box into an Altoids tin once so that 4 computer headsets could plug into one of those cheap little mixers for portable streaming/commentating. It was honestly so simple that I couldn't believe no company was selling one, in fact it was frustrating that nobody sold one because the way I value my time made it "cost" twice as much as any commercial product would have been. Anyway, good coverage of the topic. Slowly binge-ing all your old vids and it's a fun time.

[@wastenotwantnot5953]

I need to continue watching this later because this is the most helpful (to me) of the videos that I've watched of yours. The rest are good. I like your newer format and ideas nearly all of the time, but this video started connecting a lot of dots in my head.

[@clevcleverton]

love the shirt! had to have been one of the best punk tours of all time. IM SO GLAD TO SEE THIS!

[@sinus4784]

i just have doom open in the background so i just hear intense doom music in while watching this and i'm enjoying it way more than i have any right to

[@esra_erimez]

If you're having a bad day in 2018, just wait until the entire year of 2020.

[@kreynolds1123]

Electret. 6:16 Getting rid of the black magic. Some electretes do have an electric potential between two faces, but on its own is incapable of generating power. 6:30 Electrical Power requires an electrical potential and an electrical current, but to have current one must have a completed circuit. While electrets are a charged dielectric analogous to a battery, unlike a battery the electret's dielectric does not conduct electricity thus no current flows which is why dielectrics can't be discharged like a battery. Technically they may internally dischaege over a few decades. An electret's dielectric is electrically polarized with a negative and a positive surface, and can remain quasi stable for a long time. Ac power generation with an electret is possible with electrostatic induction, where by conductive plates of a capacitor are varried with an electret inbetween creating alternating periods excess electrons and not enough electrons to balance the electrostatic field between the plates. But because of the size of a microphone electret that power is very very small. Thus why the ac audio signal needs to be amplified. I'm not certain that all electret microphone amplifiers need 5 volts, but if so it's relatively easy to get 5v from say 1.5 with a simple boost converter circuit. An electret microphone amplifer won't be consumming much power anyways. All this info i provided is not important for those that don't care or who wont repair or build a diy electret mic.

[@Coincidence_Theorist]

Electrets are suppressed tech

[@kreynolds1123]

@@Coincidence_Theorist Hardly suppressed. You find one in every electret microphone. It's not used in many applications because they degrade over time which limits their usefulness. In many cases it's simple enough to create high voltages and charge a conductive surface when an electric field is desired.

[@Mark-vv1dy]

FYI I've had a shitty day too, but your video made it a bit better. Keep up the good work!

[@johnhadley1117]

you have a gift for explanation. Best on youTube

[@DiThi]

My dad taught me back in the day to add electret phantom power by just putting an AA cell in series. I think it worked but it has been at least 2 decades since last I've tried. Maybe it was a little more complicated and it needs 2 AA cells, a capacitor and a resistor. So you can do it without a power supply, and they take so little current the cells can easily last years even if permanently connected. He called electret mics "condenser mics" so I didn't really know the difference until many years later. I still think they're extremely similar: it's basically a capacitor where the insulator has dipoles, and that has a built-in transistor.

[@SSand4]

I think the reason your lapel mic can get 5v off of a 1.5v button cell is that it might have a power amplification circuit in it; same way a 500,000v TASER is run off of a 9v battery.

[@broggsey]

I have no use for this whatsoever but the angsty ranty monologue really works for me when I’m practicing piano

[@analogMensch]

Just some side information: You can use condenser mics and dynamic mics on the same device with 48 volts on, if you use good symetric wiring (you always should use good wiring). +48V are provided to the hot signal pin (2) and the cold signal pin (3) on the XLR jack, ground is on the ground pin (1). Dynamic mics have the coil between Pin 2 und Pin 3, so the DC voltage between these pins doesn't exist. The potential beween +48V and +48V is 0V.

[@cadeanderson422]

I saw a smile at the very end there!

[@videomentaryproductionschannel]

I know I'm a bit late in the day, I was looking back over your older videos and found this one, I now know why my mic would not work on my camcorder, is there any chance you could go back to this subject and show a wiring diagram and components needed please, Love your videos. Regards Barry england

[@bakonfreek]

Zoom recorders and Sony camcorders refer to this as "plug-in power" if I recall correctly. Some Panasonic camcorders refer to it as such as well, but as far as DSLRs/mirrorless cameras, they (much the same as sound cards and phones and whatever else that you mentioned) don't refer to it by anything. Also, there *is* a design for exactly this that I came across back around like 2016, but I had to have a Russian friend of mine translate it at the time (because it was on a not English site).

[@bakonfreek]

Ooh, here's a fun one. ALL Canon camcorders DON'T provide "plug-in power".. except when they do (I recently picked up a Canon HF G50 that may have been stolen, but hey, it was $200 on Facebook Marketplace basically new in box). I found out this camera kind of has the power necessary for an electret mic. It's switchable, but it (same as my old and new Sony camcorders) is 3V DC, but somehow, it works. I'm not going to ask questions because I'm fearful that some government agency might kneecap me if I do XD

[@shirobane]

I had a Sony minidisk Walkman with a “plug in power” mic socket and I found in a local second hand electrical store a tiny Sony lapel mic which came with a little unit that took a coin cell battery to power it, but discovered it worked in the minidisc without needing the power unit.

[@shirobane]

Found it. Sony ECM-T150.

[@0xredsec]

I enjoyed this. Thanks 👍

[@kreynolds1123]

I was thinking a sardine can would have been perfect project box. It could easily fit 4 AAA batteries for portability along with two stereo audio jacks, one for in and the other out. And if you want, you can include an external power jack. Your sardine can project box would also easily contain two capacitors, one for each channel to couple the audio signal and decouple the dc power.

[@Bubu567]

Acoustic power generators work, but weirdly, they don't use dynamic 'microphones'. They use special ceramic 'microphones'. More like piezo microphones than dynamic.

[@heckintech]

Intro: Holy shit can I ever relate. @33:32 and onward: You and I are kindred spirits, jesus christ.

[@MichiganPeatMoss]

Yes, Radio Shack had plug-and-play 1.5 volt AA batt powered stereo mics as well has those on the blister pack rack that used a 9V battery. Now that you mention "condenser", maybe they should've called them "capacitor mics" (even in the 80s). Hmmmm.

[@DaveSomething]

I enjoyed this video, I understand shitty days quite fucking well. :)

[@devinigh89]

I went through this same frustrating process about a year ago and it was infuriating. I don't understand why someone hasn't made a simple 5v power supply for these. I ended up making one myself, and it was pretty simple, but I kind of wish I didn't need to do all that research to get it to work.

[@cheaterman49]

Sad you had a bad day but the video was great IMHO :-) and the rants were great too haha! I suspect the reason why capitalism doesn't pick up the slack here is lack of demand? Assuming that demand has been thoroughly studied by people making the bad engineering decisions that led to this video? In many cases when you buy the most expensive "pro" device you expect the full featureset - this phantom power thing seems like it's a fairly basic (and mandatory in some cases) feature given the time and effort it took for you to implement it...

[@DavidLindes]

I did have a good time watching! And can relate to the shitty night vibe. Here's hoping 3 1/2 years later is better for you; I know this going a bit anti-capitalist at the end put a smile on my face. :)

[@gamerpaddy]

there are power adaptors where you put in a AA cell and hook between your mic and soundcard/recorder. they not necessarily need 5v to work. look for "microphone power adapter 3.5mm AA" i never understood what they are for until i saw this video.

[@lishd]

i'm one of the people who doesn't know more about capacitors than what you just explained. so i'd like to state for anyone who DOES know more & who got annoyed at you for the bit you said they'd be annoyed by: i only just barely have a hold on what daniel did explain, & i'm glad it wasn't more complicated than that, even if the explanation was technically less accurate somehow. :) i'd rather learn an estimated framework & get that clearly, than be told something i don't understand & end up dismissing completely.

[@MrFrazierNation]

Shit say, but you were winning with that shirt, sir

[@darkcisum3384]

I'm not quite sure how the jacks in a smart phone are built, i.e. what is providing the power exactly, but just a random thought, have you checked smart phone replacement parts? I once replaced some part in my old Galaxy S2 and the jack was its own part the one could have ordered. Then again maybe it was just a normal jack and the whole magic was somewhere else on the board.

[@jaykoerner]

Normal jack, the voltage is somewhere else

[@fosterdyche]

The extra conductors on phone plugs are called sleeve Stereo has tip, sleeve, ring. The original iPhone headphones had two sleeves the extra one for the microphone input.

[@dontkissmebro1508]

You can plug your headphones into a mic jack and use them as a microphone

[@Coincidence_Theorist]

Have you seen the video on resonance? Its from Russia. Early 90’s or something. I think you’d be intrigued. Electrets. Its shows how all these supposed religious symbols just so happen to be highly efficient generators on the nano scale. 🔱⚜️⛪️the circular window to the left especially. and these domes on the right. 🕌

[@ElectricEvan]

Actually I have a ton of them that run on 1.5V and 3V. 10V used to be common too for some reason.

[@ArmLessChief]

Is that a modern baseball shirt??

[@ArmLessChief]

Jk, got excited and commented before you stood up. Jeff rosenstock, just as rad.

[@ElectricEvan]

Smart phones run using MEMs mics that are fancier and have a real opamp in them.

[@sklegg]

Hellbent Brewery. Nice.

[@bborkzilla]

Here's a shoutout to Oliver Heaviside - who coined the term "Electret" in 1885!

[@BrandonChipotle]

Maybe a little to late but you can use this to provide power to the mic comica cvm ax1

[@Minty1337]

if you gave me money and i knew you had this problem at the time, i would've made it, obviously too late now though

[@TbM]

The plastic they used to isolate the middle-pin of this connector seems to melt when you heat it with the soldering iron... they still sell this crap today...

[@JohnRay1969]

At 24:25 did he say "It's like getting high on a budget." or am I stoned?

[@thanthanasiszamp4707]

I think that the term "electret" is propably "electric" in german.

[@Colaholiker]

Nein. That is German for 'no' because your assumption isn't correct. ;-) We call them pretty much the same, we just use a slightly different spelling, replacing the 'c' with a 'k'.

[@lishd]

13:11 i swear to fuck you just did a magic trick & i rewatched this segment so many times trying to figure out what the shit was happening. i thought you tore the end off that y-cable, then placed it on the table, but then the cable wasn't ripped as shown when you go to put it down. but i think what happened was you didn't pull anything away from the cable but a shadow, then what sounded like you putting the end down on the table was actually you knocking into the next piece that you DID pick up. is that right?!

[@Pink-biscuit]

you should make those and sell them

[@alunroberts1439]

So strap 10,000,000 of them to together but the cost and the space

[@lunam7249]

your thoughts are interesting . keep it up... mics to little power....investigate "tidal generators"...they do work..

[@kreynolds1123]

Reasons to breadboard a circuit before actually soldering and clipping leads. 27:42

[@jaihind3693]

Sir for HF circuits I heard Breadboard Could Add lot of Stray Capacitances

[@kreynolds1123]

@@jaihind3693 hf.... yup. Typical audio frequencies? Not as much.

[@cabanelas]

You need a compressor for that mic

[@RupertHair]

Had to wait to @8:25 to find out if the hot mic was on purpose.

[@MickeyD2012]

What you're looking for is called a preamp, or preamplifier.

[@rickybobby8563]

Sorry but when you said you got your information from Wikipedia I had to stop watching

[@a54dumb]

The use of a higher value capacitor (1 to 10 microfarads) will give the audio better bass response. The positive side of the capacitor will go to the power supply or you could use a non-polarized capacitor in a pinch. I’ve been experimenting with cheap electret condenser microphone capsules for years and they seem to work just fine anywhere from 1.5 volts to over 9 volts. I used to buy stuff from Naiant Studio (naiant.com) which did have an excellent XLR to Electret adapter, but it looks like it’s discontinued. naiant.com/pfa-specification/