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#122479 - 08/25/16 07:48 PM Re: My kinda cool build with an Arduino timer+counter [Re: Michael Bono]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
Originally Posted By Michael Bono

Meese, did the needle cord and needles get to you?

Yep just got it, Thanks again! I'll try it out in a little after I scrounge around for a BNC jack in my random parts bin, know I had one somewhere... or change to a 3.5mm connector failing that.

Originally Posted By Michael Bono

(Seems like a LOT of electronics just for a simple DC circuit. I made one with a 9V battery, a "pot" and a DC meter. And, of course, a positive wire and needle cord.)


See 2 posts above for the exact what the additional circuitry does. It's not really a necessary addition but it still does help . Making little electronics/software projects like this is fun for me and the engineer in me has a compulsive need to make things better.

Also whatever blend machine you use would very likely have something similar, if its something like DC strength 1-100 then using 50 will probably always give you 500ma no matter which person it's used on (though they probably used some sort of digital potentiometer/DAC that outputs 12v by itself and doesn't need the additional opamp I had to use since my 5v DAC was just what I had lying around).



Edited by meese (08/25/16 07:53 PM)
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#122480 - 08/25/16 07:51 PM Re: My kinda cool build with an Arduino timer+counter [Re: Iluv2zap]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
Ah I see, yeah I'm likely worrying too much, maybe a tad on the germophobic side lol
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#122481 - 08/26/16 12:54 AM Re: My kinda cool build with an Arduino timer+counter [Re: meese]
Michael Bono Offline

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Registered: 01/11/11
Posts: 3100
Loc: Santa Barbara, CA USA
Good, glad you got it. Yes, the blend machines have all the "stuff" you are talking about (I don't pretend to know about electronics) ... we just called it "constant current": set the DC and the voltage keeps the current at a constant level.

However, I have to say that something WAS lost with the newer circuits ... but, that's a long (and forgotten) story. However, without "constant current" we could tell when the client was experiencing more pain and could instantly make adjustments. They thought we were reading their minds ... but we were just watching the meter! (A slight drop and we could up the HF and go faster; a sudden spike in the DC ... we knew it was "killing" them ... gripping the sponge or sweating ...


Edited by Michael Bono (08/26/16 12:55 AM)

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#122486 - 08/26/16 06:33 PM Re: My kinda cool build with an Arduino timer+counter [Re: Michael Bono]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
Originally Posted By Michael Bono
Good, glad you got it.


Liking the new cable! No longer have a giant piece of plastic blocking some viewing angles and screw cap removes my pain of having to use pliers to replace the probes. I left the air tube on so it can't be mixed up with my foot pedal cable and it also just kinda looks nicer with it. Most importantly my machines like 50% less of an eyesore with it instead of my makeshift cord. Much appreciated!

Originally Posted By Michael Bono

However, I have to say that something WAS lost with the newer circuits ...

When I was still using the analog potentiometer I noticed that the current could rise about 50-100ua over the course of a hair treatment. Could have just been me slightly moving the needle around while tilting my head to get a good look at the multi-meter tho.

But if 50-100ua is a normal rise without constant current then maybe with the older circuits the slight current ramp up allowed you to squeeze in more DC power without the client noticing additional pain.

Originally Posted By Michael Bono

(I don't pretend to know about electronics)

I'm no expert either, but if electrical engineers get to pretend they can write software I feel it's fair I can pretend to know how to make circuits wink.
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#122487 - 08/26/16 07:10 PM Re: My kinda cool build with an Arduino timer+counter [Re: meese]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
With the last addition think I might be out of ideas for things to add to my galvanic circuit that would actually be helpful. Could add a cataphoresis switch but think the general opinion I've seen for cataphoresis here is it's helpfulness is dubious at best. There's also some sort of pulsing DC thing but that sounds like it's just to reduce pain for sensitive people and just makes treatment longer.

Also could add auto trigger on insert, not exactly helpful for slow paced DC though. Not sure how the pro machines implement it but way I'm thinking is to send out a very small test voltage at all times to determine if the circuit is complete and fire after a 1s delay. Or do they use something like a pressure or distance sensor? I remember seeing people mentioning that sometimes it triggers too early so it would make sense that they do it the simple test voltage way.

Then there's multi needle galvanic, extremely likely would be too insane for DIY. I'm imagining me wrapped up in rat's nest of cables yelling to my neighbors to help get me unstuck. And 16 probe holders is cost prohibitive.

A thermoylsis/blend circuit would be fun to make and opens up many extra things that can be added on. But would need to learn blend stuff. Might have to buy/rent a blend text book soon so I would know how to actually use it correctly.
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#122498 - 08/28/16 05:44 PM Re: My kinda cool build with an Arduino timer+counter [Re: meese]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
Actually next I'm going to change it to be controlled by my android phone over an audio cable with a mic channel, android->arduino is the audio part and arduino->android is the mic part. Android will just sends what power level it wants and Arduino will still control the constant current circuit and will send the Android the active timer, kill count and the person's resistance values.

For other crazy people looking to do something like this project this will lower the cost by $10 since the touchscreen is no longer needed.

Could also use a bluetooth chip to make it slightly cleaner. Bluetooth chips can be had for $2 but only come in 30+ pin SMT packaging which is a little ridiculous to solder by hand so would likely have to use an already soldered bluetooth module which you can find for $6 at the cheapest.
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#122521 - 09/05/16 04:38 PM Re: My kinda cool build with an Arduino timer+counter [Re: meese]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
So earlier in the week I wrote my own dinky little audio cable to android modem code just using tones and could only squeeze out 48 b/s which is insufficient for all the data I want to send. So I need to switch to an actual library that has already been written for this called SoftModem that can get up to 2450 b/s, but it doesn't work with the arduino I have since it's timers and interrupt pins are different so I need to modify it.

I've also been bumping my current up slowly, up to 850uA now and havn't noticed any additional pinkness/irritation/swelling. Planning on getting to the 1.5mA-2mA range which seems to be the max any blend or 'fast' single needle galvanic operator uses. The way I made my circuit it can only go up to 1ma with worst case 10k ohm body resistance which I thought would be more than enough but I'm suddenly feeling the want/need for more so going to switch the circuit to use 24v by just using the -12v rail as gnd and give it a max 2ma at 10k ohms and also need a better fuse setup since 24v at 1k ohm is 24ma which can be deadly. [my current fuse is a 200ma with a 13v zener diode that will clamp down and blow the fuse just in case the power supply gives > ~13.5v, max current at 12v is manageable so high fuse value was fine but with 24v it is not]
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#122522 - 09/05/16 08:26 PM Re: My kinda cool build with an Arduino timer+counter [Re: meese]
Michael Bono Offline

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Registered: 01/11/11
Posts: 3100
Loc: Santa Barbara, CA USA
Can't say I understand at all what you are doing. I do know that 1.5mA - 2.0mA is generally too much for single needle DC.

There is nothing more simple than a DC circuit and a few electrologists still use a battery (yes, really), like they did 100 years ago.

Are you using battery power ... or "plugged into the wall?" I don't "get" what you're doing, but it's somewhat entertaining. Don't "blow yourself up" kiddo!

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#122530 - 09/06/16 08:08 PM Re: My kinda cool build with an Arduino timer+counter [Re: Michael Bono]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
Saw the max current for single needle in a couple places, heres one for 1.5ma: http://www.hairtell.com/forum/ubbthreads.php/topics/102033/Re:_Failed_LHR_-_Looking_for_e.html#Post102033

Since blend goes up to 2ma that sounds like the max anyone considers safe enough for a person for any method (ignoring the person's skin's safety)

Plugged into the wall!! 9Vs are expensive and drop well below 9V long before they're 'dead' and I didn't want to shell out $20 for rechargeables.

I'm using a linear regulated +/-12v power supply that uses an unregulated 500ma wall wart plugged into a surge protector. The power supply was taken from a modular synthesizer that I built most of myself, I sold off most of it a while ago but still had this power supply left which luckily was one of the few modules I didn't solder together myself (though I have built my own wall power supply too). The PSU is something people trust with thousands of dollars worth of audio/synth equipment so I somewhat trust it with supplying current into my face.

The actual electro circuit has a few "safety" mechanisms. First there's the opamp that acts kinda like a voltage limiter since it's input signal comes from the arduino/DAC which can only ever give 5v and the opamp multiples it x2 currently so it will only output 10v max even if the main supply voltage bizarrely increases. Then the DAC output voltage is controlled by a microcontroller which measures resistance/current and adjusts the DAC output voltage as needed and also if the resistance is outlandishly high it just shuts the signal off. Lastley there's the fuse+volt limiting zener diode, reverse polarity protect diode and a 1k resistor right after the cathode/needle mostly to protect the sensitive components like the microcontroller from shorts such as the probe and anode touching directly.

Also I use a circuit simulator to double check things and a multimeter when I make the change. If/when I switch to 24v probably going to add redundant resistance/current detectors since my arduino has analog inputs to spare.

So don't worry! Chances of blowing myself up are likely less than me dying in a car crash tomorrow (though I turned 25 a bit ago and I believe car insurance companies say that means I magically became a better driver)
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#122613 - 09/16/16 02:06 AM Re: My kinda cool build with an Arduino timer+counter [Re: meese]
meese Offline
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Registered: 08/01/16
Posts: 26
Loc: Colorado
Android phone hooked up to it over bluetooth:




github project page here

Onto thermo/blend I guess! So need to cobble together some sort of 13.56 MHz oscillator circuit and amplify and control V pk-pk from the 30V to 70V range. Unlike Martha's design I have a microcontroller at my disposal which will generate the timings. Also will need to modify the DC circuit a bit to prevent RF interference from the thermo circuit.


Edited by meese (09/16/16 02:27 AM)
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