Is there any special significance to 55Hz?
It’s the frequency of common AC Mains power. The goal is an implanted light up AC power detector.
Isn’t that 60Hz or 120Hz with some transformer circuits?
I had to look up tank circuits after I posted and found out it’s just an LC circuit,the idea of this project is pretty fun project but I have mild PTSD from a certain project in school that had a similar idea but with multiple frequencies lol
Exact Hz and Voltage can vary just a bit on the mains supply line. It’s usually expressed as 50-60Hz if you look at the spec on something like the side of a power supply.
Transformer can change voltage, but won’t change the frequency (Hz).
Well it’s 50Hz for Europe and 60Hz for us, it’s a waveform so there’s obviously gonna be some variance, I guess it won’t really matter if you make your circuit work between 50-60Hz which I assume is what you’re doing? Or are you not making a passband and specifically trying to hit 55Hz?
I didn’t mean the transformer itself changes the frequency but a rectifier combined with one will double the frequency
My chances of exactly matching frequencies is pretty much nil. But… If I get “pretty darn close” I oughta still pick up enough juice, especially since I just want to light one teeny tiny led.
Of course, the problem right now is I can’t even get into the ballpark.
I’d hafta think that one through to make sense of it. Hmmm.
That said, probably not going to effect this project.
So… what is the capacitance you’re working with here? Why 38mH? Why not add capacitance to drop your inductance requirement?
Also, your final measured inductance will be a product of how exacting your windings are. Out of tolerance winds will result in lower insurance.
He’s winding for 38mH because a 220uF capacitor was the smallest one we could find that would fit in glass, and that circuit will resonate at 55Hz.
38mH is only slightly more than the coil that the LF xLED uses, if I recall correctly, so it should be feasible to wind. I wish ODaily would try it at a larger scale first though to eliminate sources of error. Starting with the final product will seldom work.
I tried to build this circuit with a 1F supercap, but unfortunately a combination of factors made it not work.
- Polarity of electrolytic caps and LEDs cutting off half the waveform
- High ESR value of electrolytic caps
- Very low field strength of AC wiring (single turn inductor)
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220uf
I considered it as a way to go to a smaller coil, ie drop your inductance requirement.
Itty bitty capacitors are rough to find, but I did come up with a maybe on a 470uf, but was suggested that I not due to something called impedance, which is tricky enough to trip up devilclarke. If I absolutely cannot get small enough, I may revisit this as a last ditch option. There’s details / history in posts from April 18th if interested. 
A little confused by this. Do you mean by how neatly and orderly they are spaced and stacked. This has been problematic for me due to the barely controllable process of spinning on a cordless drill and trying to hand tension/ guide as I go. An error in the first layer effects the second, plus new errors in the second, such that the third is bad, and the fourth is awful.
Damned Entropy.
Yep that’s what I meant 
I hate winding my own too. Hate. It.
Could you guys rig up a jig that goes on a sewing machine, where the bobbin goes and use your foot pedal to control the speed.
Or
something like a fishing rod spool
Or
make a custom variable speed motor winding jig???
Just some “easier said than done” thoughts for you both 
Thought about it.
Would really like a better way to hold the tiny little cores too.
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Just saying
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Thinking of getting one of THESE winding machines. It’s pretty obviously chinese origin, and there’s a bunch of them out there if you look around. This company, US Solid, reminds me very much of harbor freight. They’ve actually got a couple versions, but to work with tiny stuff, I think this cheap basic version, with modifications.
Specifically;
- Needs an anti-reversing feature. That will allow you to stop without having your coil unspool into a nasty snarl of wire. Could be as simple as a spring riding over the gears one way, but catching them the other.
- A wire spool holder with some kind of built in tensioner. Even something as simple as a little friction on the spool.
- The threaded rod is way too big to be of any use. I’m thinking cut if off, and attach a small drill chuck. Then I can keep using my superglue to a nail method of holding ferrite cores.
The name says electric / manual. Apparently that’s so you can attach a motor / belt to the provided pulley. Seems like a mostly bad idea to me. Also kinda hinkey.
Gotta love the warning on it.
“Due to the shaking of the transportation process, the shaft may be slightly bent when you receive. Then just knock the shaft with a wooden hammer, it will be straight soon.”
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I’ve looked at purchasing machine tools for a company I worked for years ago, and I was in contact with a French importer of cheap Chinese lathes and milling machines. I asked them why some of them came with belt pulleys / external motor options, when all the others had an integrated motor. They told me those machines are marketed for sweatshops in the Indian subcontinent that still have line shafts.
So that previous coil was about 4 layers, unknown number of turns.
Using the Microwinder I was able to get 6 layers, very neatly wound, not perfect, just neat, on a 2mm core with 791 turns. Inductance was 5.95mH. Outside Diameter was 3.13mm.
For reference, I’m trying to fit into these glass tube specs.
Need more turns. But no room for it. Gonna try smaller cores, but having difficulties holding on to them. I have ideas, need to explore some more.
I’m gonna say it again, I guess just cause I like hearing myself talk.
Build a large one to verify it works before you break your back trying to miniaturize something
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I know, I know.
But, I’m stubborn.
Also, if it works, then I still have to miniaturize, but it if it won’t miniaturize, then it’s irrelevant if it works. Basically, if I can’t solve this problem the whole thing is a waste of time.
Plus, I’m stubborn.
That all or nothing mentality is why so many amazing projects go unfinished.
Building a larger model is not a separate process from the finished product, it is a critical step to making the finished product. You’ll learn background information along the way which will not just save you time, but result in a better end product.
Don’t be too lazy to make things easier on yourself, or you’ll spend 3 times as long smacking your head against a brick wall hoping to get through, rather than spotting the edge and walking around.
I’ve been there man, I know how it is. I just want to help.
I second this, proof of concept and prototyping is really important, you’ll learn and realize things you never even considered. If you make it bigger then potential problems get bigger and easier to notice like background noise or interference for example (this is a general example I’m not specifically talking about your project)
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