Electronic stimulator

[rg07]

Hello,

I'm studying an electronic schematic, where there is electrode with current for muscular stimulation. I'm doing it on LTspice, and when i do the simulation, i have no current at the exit, instead of having at list some mA. I'm looking for a solution, maybe is the transformer not good ?

I send a square pulse from arduino to the transformer, modelised on LTspice with two generators.

 

[AnalogKid]

There is nothing on your schematic to indicate what are the inputs, where are the outputs, or shat the circuit is supposed to do. There is no "exit".

To answer what I think is your question, LTS will not tel you the current into two unconnected points because *they are unconnected*. To see the current into a load, you must create a load and connect it. So if you want to see the current flowing between two TENS pads on a human body, you must model the connection with passive components. This is difficult because the human body is much more complex electrically than a simple resistor.

ak

 

[rg07]

I will add the resistor thank you. The exit are the two little wires in the right top of the schematic, they are linked to one electrode. I don't know which inductance to choose for my transformer.

 

[davenn]

The exit are the two little wires in the right top of the schematic, they

you also have an unspecified open-ended point in the lower part of the circuit ... R8
you will have to specify what that is doing as well

 

[hevans1944]

Actually, it would help a lot if you describe what you are trying to DO.

Is your goal to learn electronics and LTSpice simulation? Or do you want to actually design and build a muscle stimulator? There are hundreds of "monkey see, monkey do" projects on the Internet. And there are dozens of already-built muscle stimulators available for purchase on the Internet, at many drug stores, and also at "adult" stores. Prices range from a few hundred dollars to several thousand dollars for scientific models. My physical therapist used a particularly nice one, after I broke an arm in a motorcycle accident, to help restore full-range motion after the cast was removed. Way out of my price range for home use though.

A stimulator that I used many years ago to stimulate frog muscles for a university research project, using freshly obtained legs by sacrificing the animals with a large pair of scissors to cleanly remove the rear legs while dropping the remainder of the body into formaldyhide, was manufactured by Grass Instruments. Almost any parameter related to the pulses... amplitude, duration, repetition rate, polarity, etc. could be dialed in with front-panel controls. This was all analog back then, including recording test results on a strip-chart recorder, but I am sure there are spiffy digital designs available now.