old high frequency tech (tesla, lakhovsky) is still in use for heal...

and the star of the show just directly at the beginning:
(powering the high frequency room for healing which is still the heartpiece of this building)

some details:

Rectifier

Spark gap

Resistors with fan for cooling... :D

Capacitor and

2 Transformers

one Tesla Transformer and a normal one

sadly not wired up correctly
but:

I love this painting :D

https://soundcloud.com/user-66149135/heaven-1

I draw the attention of visitors to my laboratory to the fact that I am neither a graduate doctor nor a professor, but only seek to help my fellow men on the basis of my knowledge.
Gallspach, 13.3.1924

However, the heart of the institute, the high-frequency treatment room, has hardly changed in 90 years. For example, the "Tesla transformer" - named after its famous inventor Nikola Tesla - has been preserved in its original state, except for a few wearing parts, and is still in operation.

https://zeileis.at/institut/

Energy for your well-being
High frequency therapy is the main treatment at the ZEILEIS Health Center. It is combined with other therapies depending on the clinical picture. The aim is to restore health and promote healing processes.
The basis for this is treatment with high frequency currents. The body is supplied with the energy it needs to activate its self-healing powers, thus leading to an improvement in symptoms or recovery.
Blood circulation and oxygen uptake in the cells are increased, activation of cell metabolism promotes cell regeneration.
There is a positive influence on the vegetative nervous system and the internal organs.
The affected body regions are treated with a treatment electrode that looks similar to an shower head and emits high-frequency pulses.

https://zeileis.at/therapien/

Starting from the mains voltage, a capacitor is charged via a high-voltage transformer, whose energy is discharged via a spark gap into the primary coil of a high-frequency transformer. A very high voltage then occurs at the secondary coil. The therapy electrode is connected to the end of the secondary coil.

The effects of our high-frequency therapy are in the physical field of mechanical nature (skin stimulus, muscle contraction), thermal nature (low heat development) and optical nature (ultraviolet light - hardly plays a role therapeutically because of low intensity). In the chemical field, there is a change in the air (formation of ozone and nitrogen oxides) and the formation of ions of both signs, and this results in a biological effect when the concentration of ions or the ratio of positive and negative ions is changed.

Transcutaneous nerve stimulation: has an analgesic effect, there is a relationship between electrical impulses and neuroendocrine mechanisms in the pain process. Certain neuropeptides, the endorphins, play a role. They are endogenous substances in the brain and some other organs, are specifically bound to opiate receptors, are able to induce morphine effects and, like other opiates, can centrally inhibit pain processing.

Now how is a pulse generated? An oscillating circuit consisting of capacitor and coil is e.g. triggered with square pulses ("surge excitation"). In the simplest case, this is a flip-flop circuit consisting of capacitor, resistor, coil and spark gap. The capacitor is discharged via a coil, the spark gap serves as a periodic switching device.

Electric impulses are not an invention of modern electronics - nature offers us an example of applied impulse technology in electric fish: e.g. the electric catfish in the ancient Egyptians or the electric ray in the Greek and Roman doctors. In the electric eel, the electric organ accounts for 58% of the body weight, and the pulses (2-3ms, 600V, 1A) are important for attack and defense. The Nile pike is a "low-voltage fish" that constantly emits electrical impulses (1.3ms, 3-10V, 300Hz) and is very sensitive to potential fluctuations in the water (can distinguish between stone and wire).

Of interest, of course, are the discharge phenomena: Voltage is applied to the therapy electrode (popularly called "brush", "broom", ...) provided with tips and gradually increased. Above a certain initial voltage, glow phenomena appear, the so-called corona (intense blue glowing aura around the electrode. With further increase, violet luminous filaments (ultraviolet light, the real diameter is 90% larger than the visible one) appear, they spray away from the tips and produce a hissing or pattering sound ("cluster discharges" = multitude of such luminous filaments, which spread away from the tips in a restless flickering and branching manner). When the voltage is increased further or a second electrode or the body approaches the tips, the predischarge suddenly turns into a spark and a short-lasting, bright arc is created between the electrode and the body. The discharges are hardly visible in daylight, which is why the therapy takes place in a darkened room, as the intensity of the predischarges is important for the treatment. The discharges at the tips are initiated by impact ionization: Very high field strengths near the tips impart such high velocities to air molecules that they can ionize further by impact. The air loses its ionization capacity and glows violet.