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12:23 AM
I wonder if anyone can guess the Tesla level of a Magnetic Induction stovetop in mT? I'm looking to do 1.4T 36 Hz bipolar fibrillation pulse for neuropathy therapy from damaged nerves..... recent arm bypass and declog damaged the nerve bundle 1% hand strengtth 3 mos time limit to heal and 1 to go
I need to generate 1kW pulses at 36 Hz with 1 to 4 Tesla focal point with a cup size flat paddle coil. My 1st sim looks good with 100uH 3mF but getting a bipolar cap with 1kVAR pulses is not going to be easy.
 
 
12 hours later…
12:49 PM
In multiplexel, how do u select which select line will go to which input
I can't be sure based on book diagrams
Like 2:1 is fine because only one select line is needed. For bigger ones like 4:1, 3:1 how would u draw the circuit
 
 
2 hours later…
2:50 PM
I was confused about which select line will get connected to which input
But I think it can by in any input we wish to
 
JRE
You don't connect a select line to an input. The select lines are an address that selects which input will be connected to the output.
 
But if I interchange S0 and S1
That would change output?
It would change the truth table
 
JRE
It would change which input is passed to the output. Look at the I_n inputs. Consider S_n as a binary number.
Oops. I see the confusion now. Ideally, the number of the input should correspond to the binary value of S1 and S0
S1=0 and S0=0 should select I0. The Wikipedia picture has it backwards. S1=0 and S0=0 select I3, which is wrong. Whoever made the drawing should have numbered the I from 0 at the top to 3 at the bottom.
 
3:10 PM
Thanks. That makes sense
 
 
1 hour later…
4:40 PM
Hi guys. Quick w, I've got a pcb with a burnt out component - would it be on topic to post up a q asking for help identifying it so I can source a replacement?
 
JRE
4:55 PM
@CaiusJard There are lots of parts identification questions on the EE site - they are on topic if you follow the guidelines.
 
 
2 hours later…
7:12 PM
Any Magnetic Gurus know how to design 2T bipolar 1kW pulses in a cool coil with 33 Hz SINUS pulse near 300 Hz BW ? Here is my failed attempt with thermal issues. It needs to be more like 0.1% PWM not 50% tinyurl.com/yxf25w4b > I am working on acoil design too andDCR,ESR,Ron are all critical
2
 
 
2 hours later…
9:13 PM
@TonyStewartSunnyskyguyEE75 I've made some pretty powerful electromagnets in my past using copper plated discs that are supercooled to there critical temperature. But I havent attempted a bipolar magnetic field layout before. That is if the bipolar fields are on each side of your device. What I would do is take another look at the basics of what you want your electromagnet to do. Then analyze it for the raw materials you'll need, then you'll know what you will need.
 
9:25 PM
@TonyStewartSunnyskyguyEE75 I'm sure you have looked at the formula to calculate the force put on your coil. But if you haven't yet, that would be a great place to go. It'll tell you what material you'll want to get based on the stress force the coil is under. The result you get for the electrical stress may also help with heat problems.
@TonyStewartSunnyskyguyEE75 But I have a very good feeling you're on the right track. And I'm pretty sure you'll figure it out. But since it seems that you're wanting to do a bipolar field I would love to hear the way you did it. :) I could learn more about the bipolar field behaviour.
 
9:41 PM
@TonyStewartSunnyskyguyEE75 I wish I could give you more help on this. But circuitry of that type isnt my speciality. But I do know how to make a 2 T magnetic field using AC. AC has a dominant Positive end and a dominant negative end even though it is AC.
@TonyStewartSunnyskyguyEE75 I made mine with a couple transformers a special type of material I used for the coil. As well as a cooling chamber to allow the liquid nitrogen in at. The chamber would allow the liquid nitrogen to cool down the coils in a way so I wouldn't need flowing liquid nitrogen.
I also ordered a custom sensor that shuts the system down when the temperature gets too hot or when the liquid nitrogen is low. I made mine so I can fill it up like a gas tank. And of course I had to do other smaller details like a pressure release valve.
 
It’s a well defined SINUS 200 Hz BW Q=0.5 33Hz Rep rate bipolar pulse and cool coil in a hand held paddle against skin. when Activated
, murscles move
spec sheet s 1.4 T centre of spiral coil
No force
No pain
 

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