Abstract: Disclosed is a method for electrical supply of an apparatus by a system including an intermittent electrical source, electrical storage unit, a fuel cell, and an electrochemical unit for generating the fuel. The method includes steps of: determining a power balance of the system depending on the power consumed by the apparatus and supplied by the intermittent electrical source; receiving data representative of the stability of the power balance during a safety period; controlling the fuel cell and the electrochemical unit: to activate the electrochemical unit if the power balance is greater than a first threshold and the data are not characteristic of a subsequent decrease in the power balance; activating the fuel cell if the power balance is less than a second threshold, which is less than the first threshold, and the data are not characteristic of a subsequent increase in the power balance.

Abstract: Disclosed is a method for electrical supply of an apparatus by a system including an intermittent electrical source, electrical storage unit, a fuel cell, and an electrochemical unit for generating the fuel. The method includes steps of: determining a power balance of the system depending on the power consumed by the apparatus and supplied by the intermittent electrical source; receiving data representative of the stability of the power balance during a safety period; controlling the fuel cell and the electrochemical unit: to activate the electrochemical unit if the power balance is greater than a first threshold and the data are not characteristic of a subsequent decrease in the power balance; activating the fuel cell if the power balance is less than a second threshold, which is less than the first threshold, and the data are not characteristic of a subsequent increase in the power balance.

Abstract: An emitter for a system of electromagnetic tomographic measurements, as well as a process and a generator (5) adapted to produce a variable frequency current supplying a solenoid (1), constituted of turns wound about a magnetic core (3). The solenoid (1) is constituted by several windings (4a, 4b, 4c) disposed side by side with each other on the core (3), and the emitter comprises switching means (6) adapted to connect in series or in parallel and/or to disconnect the different windings (4a, 4b, 4c) with and from each other, constituting the solenoid (1), so as to control the number of active turns of the solenoid (1).

Abstract: aN emitter for a system of electromagnetic tomographic measurement, as well as a process and a generator (5) adapted to produce a variable frequency current supplying a solenoid (1), constituted of turns wound about a magnetic core (3). The solenoid (1) is constituted by several windings (4a, 4b, 4c) disposed side by side with each other on the core (3), and the emitter comprises switching means (6) adapted to connect in series or in parallel and/or to disconnect the different windings (4a, 4b, 4c) with and from each other, constituting the solenoid (1), so as to control the number of active turns of the solenoid (1).