@@kapitany7449 nothing wrong with Arduinos. I use Arduino all the time. But, you are constrained by the modules you can buy. There are a lot of problems not adressed by popular youtubers just because there is no "Arduino module" to solve those problems.
@@guatagel2454 Understandable! I'm just a novice and reading your comment I thought there's a flaw in Arduinos or something. But you're right, it's not easy to search up fun electronic projects without Arduinos unfortunately. Thanks for the explanation!
At the 6-minute location you mentioned grounding the input of the unused opamp. This works well for bipolar power supplies but is often out of the common mode range of a single supply opamp. It is OK for your selected device (a rail-to-rail input and output device), but a better (more general) solution is to run the + input to your 2.5V reference. This way the opamp doesn't need to work as hard to make the output try to go to ground.
I love the old school analogue stuff. I like circuits that send signals through their own power lines. The receiver is so simple and elegant. Just 2 wire twisted pair! No gold plated; oxygen free, audio snobbery!
This video, your presentation style, and the way you designed and built the board at the end tickle all the right part of my brain. The simple current loop... Beautiful.
I am loving your content! I have a Computer Engineering degree and feel comfortable working with digital systems and programming, but there's always this sinking feeling I get when I think about having to solve circuit problems or implement a functional circuit for something from scratch. I like your videos because they cater to the edge of my skill level while still being understandable and inspiring. I ordered some two sided copper FRN boards and basic components to try to replicate some of the projects on your channel!
That's very efficient design in terms of complexity vs resulting quality - when I heard the problem in the beginning of the video, I've thought of something generally similar - but it was much more complex as I imagined it
Your detailed explanations of the circuit sections allow me to learn techniques/understanding that I can take on to my own projects, Leo. For example, quieting the power supply to the mic. It's also very instructive when you explain the practical limits of design choices such as how much current will flow in the loop. You have a totally relatable Art of Electronics way of explaining all this analog stuff that fascinates me. Thank you so much for sharing your work.
What an awesome idea! I especially liked your self-made PCB design. Did stuff like that many years ago, nowadays I just fire up KiCAD and order some cheap boards... Gotta love your totally calm way of presenting your content ❤️
Leo: Very much enjoyed your video. I too have 'engineered' many innovative solutions but I never tire from looking at another engineer's solution and you've become one of my favorites! Current loops (for so many applications) are very underrated and a lot of engineers try to force common-mode voltage signals around the design environment with the expected dismal results. Even if you are talking digital signals, current loops offer much greater noise-margins and vastly lower implementation-costs! Even if you "bastardize" a solution into a pseudo balanced system, you can get great results. Along time ago, I found out that you could pipe NTSC video without using 75-Ohm coax and just use a simple twisted-pair instead. Also, current loops allow a nearly infinite amount of devices and are inherently easy to detect faults and troubleshoot. Great you posted this video and also showing the use of two transformers for signal enhancing while obliterating common mode noise. Thanks for posting!
You got me with the link bait title. I stuck around as soon as you mentioned We Live In Public, and I left a happy viewer after seeing your schematics. Thanks for sharing and if you have any other pseudo stories, we’d love to hear them :)
Awesome detail and explanation. I was thinking sweeping for bugs, something more TSCM and my imagination went off more on my wishlist of them RDF to hunt down the source if wireless.
For me the most useful part of the video was right at the end where you showed your construction technique. The whole video was very interesting and I really appreciated the explanation of how the circuits actually work. Thanks.
Bastard Operators have been using CAT 3 and CAT 5 cables for microphones for decades. mic wired up to the office network jack with an amp speaker / recorder in the wiring closet. This is not new, but glad it found a productive use of thr technique. ;-)
I've been subscribed to you since your first couple videos, but hadn't seen anything since the "Laser Bamboo" video. Happened across your channel again and I had been unsubscribed! I know for a fact I was subscribed with the bell. RU-vid is playing games again I think. Anyways, Another wonderful video!
Nice presentation! This is like how RFID chips get power and communicate, but with wires. In an RFID system, a typical keyless entry card has no battery. The card reader transmits RF energy to the card, which rectifies it to DC. The card sends back data by varying the load on its antenna, like Q1 in Leo's circuit (at 5:50 in the video). The card reader senses the load changes.
5:29 or so, I believe that graph is valid only when using powered microphones (ie. electrostatic mic with phantom power, or having DC voltage across a coiled mic - the latter is equivalent to using a speaker in reverse and makes very little sense as it will distort the signal*). please correct me if I'm wrong. * that's because on the "upper" part of the signal, there will be more current flowing through the wires and therefore more attenuation.
Copious comments below! Please keep producing videos! Even more on electronics you have made in the past and design decisions. Thank you for making the videos!
Wow, great video. I loved the explanations with schematics and data sheets-- I understood everything. Great way to explain the concepts! Maybe current loop is a lost lesser known solution, so nice to see a design explained in detail. But at >$100 per microphone I wonder if a digital solution is better. With $2 ESP with WiFi/Bluetooth or ARM with line drivers, some with MEMS microphone controllers, is an analog transmission optimal? I loved the footage of your rectilinear cut SMD PCBs, or whatever you call it was. (I remember your prior video on that.) I haven't tried that yet myself, but it is inspirational. Thanks for another thought provoking video.
The parts cost maybe $10.00 it's not the cost of parts, but the cost of LOW VOLUME MANUFACTURE that makes it $150.00 a unit. Make 1000's of something and it's cheap, but make 40 and the price is NASTY.
4 microphones? 5 microphones or a CAT5 cable? I count 7... + ground that makes 8 wires. You can even push it a bit further and use the shield as a ground. there might be some crosstalk, but if the microphones are situated in proximity to each other there will be acoustic "cross-talk" anyway.
Hi Leo, may I suggest you format the videos to ask for the subscribe and like a little earlier. It struggle to do it before RU-vid takes me somewhere else.
Great video, how can I download the schematics? What type of microphone was used, whould any modification needed for it to work with the high impendance piezo sensors?
I enjoy your channel, and this vid was particularly interesting to an old tip and ring guy (me.) However, I have to chuckle a bit at your circuit build technique. Small PCBs are easy to design and very cheap to buy...as in 10 for $30 delivered from China in a week from the time you submit the Gerbers. You can put your tin snips out to pasture. 😊
@@CarlMarvin Exactly. For low volume prototyping this technique is just about perfect. (He has an excellent video talking about his prototyping tools that is well worth a view). The only thing that might be better would be a cnc mill suitable for pcbs. But that is only really worth it if you are doing a lot of prototyping.
@@CarlMarvin For design checks of non-RF boards, I use solderless breadboards. They are reusable, quick to assemble, and easy to revise. They also don't require any solder, flux, or grinding tiny particles of copper and fiberglass into the air. 😊
Nice...I like it :-) Reminded me of the time I used SATA cables for high-speed analog signals. Not sure why you used 2 xfmrs on the rx tho. A single unit should give all the CMR you need, no?
The main source of common mode nasty is capacitively coupled AC mains voltage, this gives you currents flowing the same direction in both wires. How do you convert the varying current flow into a voltage that is insensitive to common mode without a cancelation trick?
@@leosbagoftricks3732 Hmm, are you saying that the double xfmr is needed because you're operating in current mode? CM current will be flowing in stray capacitance for the most part, yes? So CMR will largely depend on balance? I still don't grok the 2-xfmr need. Nor have I ever seen it elsewhere. Still...willing to learn a new trick if I'm missing something! p.s., the circuit conjures memories of the olde POTS "hybrid" circuit :-)
I liked every second of this video but couldn't figure out the connection to the video title. Am I missing something or the title is somewhat poorly chosen?
@@leosbagoftricks3732 I didn't want to write that down :) I watched all of your videos, without taking the title into consideration. You dont need click-bait:)
your home made mics are $150 each? serious? WTF!.. how the hell.. i could get all them components for about $15......did you mean $150 for all the mics?!
