APRIL 2024 Until this section is updated, here are some of the main diagrams, which can be enlarged as required .
This is a transportable but functional model, to be powered by two or three photovoltaic panels, to be installed as a bypass on a swimming pool recycling circuit, or to be powered (for demonstration purposes) by a garden fountain pump immersed in a can or barrel.

Below: the heat exchanger made up of a 50 x 50 mm tube fitted with ceramic resistors. As part of a model for a swimming pool, the ends can simply be sealed with a PVC or other plate fixed with mastic-glue.

Below: the box waiting to receive the control plate ;

Below: the box with the control board.
1 - Current and voltage collectors
2 - Arduino microcontroller
3 - MOSFET switches
4 - Voltmeter
5 - switch

Control system power supply :
6 - DC-DC converter
7 - USB battery