Patent ID: 7965484

Claim:
A speed controller comprising: as input, a rectifier module for generating a direct voltage on a power bus from an alternating voltage available on an electrical power-supply network; a bus capacitor connected between a positive line and a negative line of the power bus; and an inverter module powered by the power bus and controlled to deliver an alternating voltage to an electrical load; the speed controller including a protection device for protecting the speed controller against overcurrents linked with voltage variations on the electrical power-supply network, the device including a first electronic switch located on the power bus in series between the rectifier module and the bus capacitor; a first resistor mounted in parallel with the first electronic switch; an assembly including a second electronic switch and a second resistor mounted in series, said assembly being mounted in parallel with the first electronic switch and the first resistor; and control means for controlling the first electronic switch and the second electronic switch.