Milovana.com

I will shortly put this guide into this OP but I thought I would up the initial rar`d guide I`ve quickly wrote out to let people have a look at it. If there is anything you think I should include in the guide or isnt quite understood then please do post and tell me so I can do my best to word things or explain stuff better..

if you have a question on the guide please also dont hesitate to ask.

you will need to unrar/unzip the file, it contains 8 pictures and a text file. Ideally open the pics in one window and the text in another, and flick through the pics as you read through the guide.

again your feedback is very much appreciated and very much wanted on ways to improve it.

download (2.4mb) is here: Stereo Stim DIY Guide
Original Davey guide in pdf format: Davey Guide

Thanks!

1) I would like to see a link or picture for the speakers you purchased (not disassembled) to better understand what I'm looking for.
2) I would like to see tech specs for transformers, in case I can't find the same model in my country.
3) Does it require batteries? I mean the one You used.
4) what about electrodes? Which do you suggest, or do you create your own? If so I'd like to see.

Nezhul wrote:Thanks!

1) I would like to see a link or picture for the speakers you purchased (not disassembled) to better understand what I'm looking for.
2) I would like to see tech specs for transformers, in case I can't find the same model in my country.
3) Does it require batteries? I mean the one You used.
4) what about electrodes? Which do you suggest, or do you create your own? If so I'd like to see.

1)
Typing folding portable speakers into ebay should provide hits.

2) Radio Shack = (2) 273-1380 Audio Output Transformers 273-1380
The 45-701 transformer @ electronicplus.com
The LT-700 from Maplin (UK) LT700

3) The unit can run from usb power or from battery power thats your preference, I prefer usb as it saves buying batteries.
4) yes I made my own electrodes which I`ll take pics and post shortly.

As another reference point here is the original Davey guide which includes electrodes aswell, the reason I made a guide was I felt the davey one missed out some info like which wires to use etc, it actually may be worthwhile getting an adobe reader editor and just adding the missing pieces or rewording to be more user friendly.

Davey guide in pdf format: Davey Guide

any one of this transformers may do?
http://www2.mouser.com/Xicon/Passive-Co ... s8Z1yzmq1t

As I understand the main concern is impendance value?

Nezhul wrote:any one of this transformers may do?
http://www2.mouser.com/Xicon/Passive-Co ... s8Z1yzmq1t

As I understand the main concern is impendance value?

The impedance certainly looks on par with the radioshack ones I`ve linked above, I`m not gonna pretend to be an expert but going by the values I`d say they should work though I`m not making any promises lol but yeah values look good :)

the radioshack ones are the same primary as I use, the diference is there secondary is 8ohms, the ones I use are 3.2ohms secondary but the radioshack ones are known to work, I might even purchase a couple with the 8ohm secondary see if it makes a diference.

do you know how impendance affects the stereostim thingy?

Nezhul wrote:do you know how impendance affects the stereostim thingy?

As far as I`ve read just now in regards to impedance its to do with how resistance basically dampens the signal...

so in thought, to stim its taking a high end signal and dampening it down to a more pleasing level for use in the body.

I`m assuming the greater secondary will simply give you a higher controllable range.

I am gonna order a couple with the 8ohm secondary just to try it though, you got me curious as to what diference it will exactly make :)

edit** actually come to think of it when I first built a box I had bought the wrong transformers, the primary being 20ohms,, it did exactly as I said above but dampened the signal way way too much to the point that you could tell it was working but wasnt producing anywhere near the strength it needed to..

edit*** looking at the specs of the ones you page you posted, me if I was buying one from those 4 would go with THIS one. The reason being is its the only one that has a power rating of 200mW which the transformers I use are.

I use the Radioshack audio output transformers. Works great. Even when someone is remotely in control of the settings.

Tzahrkiya wrote: ↑Fri Jul 17, 2015 9:10 pm
edit*** looking at the specs of the ones you page you posted, me if I was buying one from those 4 would go with THIS one. The reason being is its the only one that has a power rating of 200mW which the transformers I use are.

I have purchased the ones you have linked above, but I cannot figure out the configuration of the transformers wire connection. The mouser transformer has six connection points. How would you wire one of them with the speaker box?

Hello

I made a couple of these using the recipe provided with the intention to sell and I can say that it is by far the best e-stim experience that I have ever had in 7+ years of stimming.

I made 3 +1 of these and put them out on a norwegian "free market" site to sell.
https://www.finn.no/bap/forsale/ad.html ... =112535140

You can buy one there through official channels where you can make safe payments or you can PM me here if you want to go unofficial or if you have any questions.

Nezhul wrote: ↑Fri Jul 17, 2015 9:01 am any one of this transformers may do?
http://www2.mouser.com/Xicon/Passive-Co ... s8Z1yzmq1t

I've built a box with those. They work, but the performance is less than ideal. I believe you'll find the bandwidth drops off at 3400Hz. Their power handling capability is also iffy.

Try Parts Express item #300-040.

Andrus wrote: ↑Mon Dec 09, 2019 1:22 am I've built a box with those. They work, but the performance is less than ideal. I believe you'll find the bandwidth drops off at 3400Hz. Their power handling capability is also iffy.

Try Parts Express item #300-040.

Relevant bandwidth is about 400 Hz to 1200 Hz. You can't feel higher frequencies and much lower frequencies are dangerous and should therefore be filtered. Such a filter also protects the transformer (low frequencies are transformed into heat).

Part with 4Ω input impedance would be better, but I also successfully tested a 12Ω part (see this post and also the earlier ones)

The transformer ratio 1:10 is okay (should be as high as possible).

Loose wires are not ok, not inside walls nor inside machines.

Low signals are no problem as long as you keep the power rating on par with the area and volume. TENs units are used and sold in the millions and only range from 0-160Hz, EMS units go higher, both used in medical applications - and there is a high standard for medical instruments. At least if you want the certificate for it (leak currents or floating circuits). However, these do not offer decent stimulus, but please don't spread false statements. And yes, direct current is unwanted, but also an offset to your alternating current is not a smart thing! It can cause electrolysis either way: you need to make sure there is no offset on your signal or else it doesnt matter if you have 1kHz buzzing around, if the amplitude is offset (meaning you have a dc part in it ).

Any signal carries energy and will produce heat. Your CPU works probably around 3.600.000 Hz PER CORE, and I do not see how that is not giving up massive amounts of energy . With the range up to 2kHz we wouldnt even start to talk about "high frequencies", tho some effects in circuits can already take place (impedance matching networks). It is ok to experiment, but please, stop spreading false statements. I know you might not be able to read a microelectronics circuits book, as basic EE knowledge and higher math is missing, but please ... at least try to do that. You can and should pre-filter, but filtering your signal afterwards is essential. So, stay safe and rather use battery powered DIY applications.

tudeloo wrote: ↑Tue Dec 31, 2019 10:30 am Low signals are no problem as long as you keep the power rating on par with the area and volume. TENs units are used and sold in the millions and only range from 0-160Hz,

You mix up modulation frequencies and carrier frequencies. I'm quite sure that there is no medical stimulation device that delivers a 0Hz component.

No, I do not. AC. Period. Nothing to do with modulation or carriers. However, you might be right that the range might be 2Hz-160Hz and not including DC. (e.g.> https://www.tensunits.com/product/TU7000.html )

Still low frequencies and your statements are still false. With DC we do not talk about frequencies, obviously. Still, I suggest you measure your signals, as a dc part will have the same affect. Set your osci. to dc, see if signal is offset from y-cursor position set to 0V ! Use a coupling capacitor to load if you want to make sure there is no dc, capacitance depending on circuit.