I am 45 years old, once married, and started playing with electrostim about 2 years ago. Between being married and finding my new girlfriend, I acquired a Beautronix slimming and toning machine, the type women use. This came with 5 channels and 10 pads, and delivered a variable, about 50 Hz buzz, every half second at max. setting. This only served to whet my appetite!
I'll put this in 2 halves, the first the basic engineering development of the unit, and second the sensations and use.
I discovered that a metallic (gold colored) vibrator in my anus produced some very interesting sensations when coupled to the device in place of one or more pads.
Being of an electronic engineering background, I delved deeper into the Beautronix box and discovered that it was basically 12V with a transformer output to pump up the output and provide channel to channel isolation. A power FET was pulsed to provide the interrupted DC to the transformers to get the output. This was of the order of 50+ volts open circuit, though dropped under load. A quick go with the soldering iron, and the output frequencies were much higher and variable, - much better! (around 2-4KHz)
At the same time, I tried making a switch matrix to enable the flow of current between pads and anus, good effects, but a wiring nightmare!
Also at this time I made a penis probe, which allied to the switch matrix worked very well indeed. The probe was made of stranded wire with a long thin loop at the end, covered in solder to make a smooth elongated blob. A silicon rubber sleeve was placed over the main wire and glued at the end to make everything very smooth and comfortable.
The power supply for the Beautronix machine died, so I then thought how to improve on what I had.
I had a microprocessor development board for an old obsolete processor, the Z8, with integral Tiny Basic on the chip, which made it easy to use, and I built a 'new improved' device around this.
It struck me that if there were more electrodes both anally and in the penis, and switching could be done between them, it could be a *good thing*. I used opto-triacs to do the switching and the processor to operate the switches. I used 2 channels from the original unit, and controlled the processor from the PC.
I also made up two new probes. The anal one was made from 0.25 inch segments of 28mm copper tube cast in resin to produce a probe with 7 'rings', all brought out as separate connections. The penis probe was 12 inches long and made of small sections of very thin copper tube with silicon rubber between them. The tip section was sealed with epoxy and that also held a thin kevlar string, that with the wires, should stop anything getting stuck if something were to break, I should always be able to get the probe out (I hope). This probe also has 7 segments.
I intend to develop the unit further, as with software control, the sky should be the limit!
As regards safety, it does scare me a little. The unit is grounded very carefully, all mains connections are double- insulated, all mains transformers are separate bobbin types. The output is transformer coupled, and the switching is done by opto-triacs, so hopefully it should be OK, but it still scares me!
As regards sensations and use, I currently use 2 pads on my lower spine, one pad on my crotch, the anal probe and the penis probe.
I use KY jelly on the pads, and squeeze some into my penis to ease the probe in. Beware, not all lubricating jellies are suitable, Boots for example feels like it burns slightly in the penis. I always use pre-injection wipes to clean the penis probe to stop any infections occurring - so far its worked well.
If I get the penis probe in the correct position, about 9-10 inches in, when the switches change the individual contacts, it can feel very similar to manual masturbation, only much deeper and more intense. By careful adjustment the penis tip can be made to 'fizz' and the other internal muscles rhythmically contract. The very best though, is when the probe seems to hit on, maybe the prostate, and the penis feels enormous and is very hard indeed. As the voltage is raised, it feels as though you're going to come, and it feels exactly like you do, but you don't ejaculate. As one "orgasm" finishes, another one starts, and you seem to be able to have more or less continuous "orgasms" for hours.
The first time this happened to me, I could not believe I hadn't come; I thought "Oh well, that's over" little realizing it was just the beginning!
I find that after the first session of these very intense "orgasms", I feel like I have really come, and find it hard to get another erection without waiting for 15-20 minutes. Strangely, it is possible to have these 'fake comes' as I call them, without having a very stiff erection.
When I do finally choose to come properly, (usually 3-4 hours later!) I start with a low voltage to excite, get the probe right on the 'tickly spot' and as orgasm approaches raise the voltage. At orgasm, the muscles try to contract, but cant really, and the orgasm really lasts and lasts, with semen finally just dribbling out - Wow!
Overall, electrical stimulation certainly works for me, a totally different experience from normal sex, and with care can be safe, though I have had a couple of skin burns in the past.