I'm toying with the idea of making the muscle stimulator circuit as offered on the following site: http://www.redcircuits.com/Page124.htm

Can someone tell me if a 110v/12v transformer could be used in place of the circuit's specified 220v/12v transformer. Besides being half voltage, what change, could one expect in the output?

Would it be a practical alternative to place a one stage diode/capacitor ladder after a 110/12v transformer to match the equivalent circuit spec. transformer?

 

Well you see... 9V into that circuit will produce around 120V as it says in the notes. 3V will produce around 40V (simple maths)...

Therefore, you will get approx. 20V out from 3V using your 110V Xformer and 60V out at 9V. There should be no problems.

Edit: Don't worry about the voltage doubler.
Edit 2: Find a 110V to 6V Xformer...

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What is a joule per second?

 

Thank you for the explanation Erosennin.

 

Hi Algabon,

I took a brief look at the circuit and I found it not worth building. A muscle stimulator must be able to produce different programs as individuals require individual treatment.

The frequency a muscle stimulator uses is fixed (15.384KHz (~65ms), used in hospitals), but there are different programs varying in times between pulse bursts and of course the intensity of the bursts must be variable too.

More than 40V - even in the audio frequency range might be fatal if the electrodes are not placed properly. At 40V the device causes discomfort already.

If you want to use for medical treatment I'll help you out and send you my design including the software. (Device name LIMS = Low Impact Muscle Stimulator) The output has a safety circuit not to exceed 39V.

It is also not recommendable to use a normal (inverted) mains transformer since its capability to transform square wave AF signals is not the best. Better use a self-made iron powder or ferrite core transformer with an air gap to increase battery life (less DC transfer, hence less current flow).

Under no circumstances use power - even gained by a power supply from mains voltage. With the smallest malfunction you will electrocute patients. Using an on board battery charger it should be safe enough to disconnect the entire device during the charging process.

Regards

Hans

P.S. The device of that link produces only half waves only. It must produce AC! (Preferrably a sine wave). Otherwise it's totally worthless for medical applications.

 

A Chinese guy was selling millions of a "muscle twitching device" on infomercials on TV. He is now a multi-millionaire. He is banned because the government tested it and found that it is useless for building muscles instead of working the muscles.

Quack doctors use a similar device called TENS for pain relief. Look in Google at articles that say they are also useless.

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Uncle $crooge

 

Hi audioguru,

you're right again. However this thread was covered already. A muscle stimulator is made for faster recovery of present muscles, e.g. after a traffic accident and a long stay in a hospital with a bandaged leg.

Imagine one of your legs being unable to move for about one month. Taking off the bandage you'll think first that leg isn't yours. That device brings the muscles to coordination faster than just training.

The quack doctors might have misunderstand the priciple of this device. They can of course increase pain with it using the proper voltage!

Hans

 

But it's a terrible idea for a project, IMHO. You could potentially electrocute yourself. 99% of the sales are based on things they can't do- they can make some muscles twitch but do nothing to exercise or tone you. For the few valid medical uses, get the medical device. It's unlikely a homebuilt device with internet plans you don't understand is going to give the correct waveforms or usage instructions- you don't even have the right electrode pads here. I mean if you have a traffic accident and the doctor decides this is appropriate therapy, are you gonna throw away the prescription and start soldering one together??

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

Thanks to y'all for your input on the circuit. It was just another project-build idea; and to have a gadjet in the end to show for.

Boncuk, your additional insight onto the project has piqued my curiosity from a technical point of view. Know of any links that could further inform on the topic?

 

Hi Oznog and Algabon, (in this sequence)

what does IMHO mean? Sorry, but a foreigner can't know all the abbreviations used in the English language. Concerning the effective use of such a device there are lots of problems all over the world. The name of these problems is MONEY. Most of the people e.g. here in Thailand can barely afford to pay a doctor. There is also no social security system here. You certainly can imagine that they won't use an apparatus in a hospital with high charge. Proper electrodes are just a minor problem. They can be made easily using stainless steel plates and variable straps to fix them. (Like they are used in hospitals).

Algabon, I don't know of any link towards that device. I only know that I inspected it at a hospital and implemented the functions in an MCU. After a long search I have finally received the necessary ferrite E-cores to make an AF-transformer. My first "victim" will be a neighbor. She broke her leg about one year ago in a traffic accident and she is still suffering from it.

Regards to both of you

Hans

 

IMHO = In My Humble Opinion

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

I think he makes the Q-Ray Iconic bracelet thing (also does nothing)

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

In My Honest Opinion???
Is anybody humble anymore?

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Uncle $crooge

 

Is the Q-Ray a useless copper thing or a useless magnet?

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Uncle $crooge

 

Well that's your opinion
http://www.learnthenet.com/english/glossary/imho.htm

Do you remember Humble Howard? (Radio personality)

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

Personality Howard Stern is not humble.

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Uncle $crooge