Part 6 AUTOMATION OF PTC RESISTORS

The first sketches of the cooker envisaged automated regulation of the number of resistors according to the amount of sunlight, using an Arduino micro-controller and a small computer programme.
It soon became clear that, in the context of solar cooking, automatic control was totally unnecessary, given the flexibility of the PTC resistors. So the Arduino microcontroller, Mosfets switches and computer programme were put on the back burner.
However, when it comes to producing hot water, the automatic control system has been given a new lease of life, enabling the water heater to operate from sunrise to sunset.

While waiting for the programme to be updated, you will find below the execution drawings of the control board supporting the hardware adapted to the operational model of the water heater presented in part 7.
The programme is fairly rudimentary: the micro-controller reads the current and voltage, calculates the power, then upsets the balance by adding a resistor; after a few moments, once the new balance has stabilised, the micro-controller takes another reading; if it's better than the previous one, then it continues in the same direction; if not, it goes in the opposite direction, and so on...
While waiting for the programme to be updated, you will find below the execution drawings of the control board supporting the hardware adapted to the operational model of the water heater presented in part 7.
The main purpose of this board is educational: it's obvious that manual wiring would be impossible to sell, and that the solution would involve an integrated circuit board, but that's beyond our immediate scope.

Below: overview of the main board and the auxiliary board for the power supply to the main board
1 -capteurs de courant et de tension
2 - Micro contrôleur Arduino
4 - Voltmètre, pour information
5 - interrupteur
6 - Convertisseur DC-DC
7 - Powerbank

CONTROL CIRCUIT

a) Control circuit - Earth wiring

b) Control circuit - Component power supply wiring

c) Control circuit - Wiring the control-command circuit

The Control circuit is complete!

POWER CIRCUIT

a) Power Circuit - Earth wiring

b) Power Circuit - Power supply wiring

c) The Power Circuit wiring is complete!

Wiring the control unit power supply board