Abstract: A circuit device is provided for driving an AC electric load, of the type inserted between a terminal of an AC power supply line and a terminal of the electric load to be driven and including a generator of PWM signals to be transferred to the load. This circuit is an AC/AC converter adapted to power supply the load from any level of the power supply line sinusoid and comprising first and second voltage driven switches, the first switch to power supply the load and the second switch to enable loop-back of the current. The switches always operate in a complementary manner, i.e., when the first switch is on, the other is off, and vice versa.

Abstract: A circuit device is provided for driving an AC electric load, of the type inserted between a terminal of an AC power supply line and a terminal of the electric load to be driven and including a generator of PWM signals to be transferred to the load. This circuit is an AC/AC converter adapted to power supply the load from any level of the power supply line sinusoid and comprising first and second voltage driven switches, the first switch to power supply the load and the second switch to enable loop-back of the current. The switches always operate in a complementary manner, i.e., when the first switch is on, the other is off, and vice versa.

Abstract: A fluid flow meter is of the type including a heated probe sensor of known electric resistance dipped into or swept by a fluid stream having a predetermined velocity. The sensor is capable of converting each flow velocity value to a voltage value, and is connected to a processor operating using fuzzy logic for producing the flow measurements. The sensor may be an NTC thermistor. The thermistor may be powered from a current generator, and the processor may include a neural network. The sensor may include at least two discrete thermistors, one being a hot thermistor and the other being a cold thermistor.