In fact, the issue of obtaining "free" electricity, as well as mobile sources of electricity, has been facing humanity for a long time. Back in the 18th century, when electricity was mainly "entertainment", the first sets appeared, consisting of an ebony plate equipped with a penis attachment and a fur "muff" that could be used in foreplay and entertain yourself and your partner with the view of jumping off sparks and electrical stimulation intimate areas. Later, the phenomenon of inductance was discovered, which made it possible to obtain energy more efficiently, and the sets were somewhat modified. The basis was a magnetized rod inserted into the urethra, and a small coil in the form of a copper ring, which moved along the organ in reciprocating movements. The resulting electricity could be used in the simplest vibrators or, again, electrical stimulating devices. The photo shows a part of a set of one of such devices, it is even equipped with a bell that is triggered at a certain voltage threshold, and signaling that the exerciser is making sufficient efforts.
And here is a more advanced device based on the phenomenon of self-induction. separately, it should be noted the aesthetic component - the movable guide is sewn into elegant gloves.
On the right in the briefcase is the part that is inserted into the urethra of the erect penis (I must say, its size was chosen with a good margin), and on the left is a paired female stimulator.
Recently, however, this kind of design has practically become unpopular, due to the ability to get enough electricity from banal batteries. Still, the urethral liner of such devices is a rather inconvenient thing, and few men voluntarily agree to use their urine.flax channel in such an exotic way if there are more lenient options. Well, the risk of all sorts of injuries and infections when using such devices is still quite large.