Description
The STEVAL-ISF003V1 evaluation board allows limitation of the inrush current charging a DC bus capacitor, to comply with standard IEC 61000-33. This inrush current limitation is based on a soft-start procedure of the mixed bridge diodes and SCRs rectifier using progressive phase control at board start-up. This solution drastically reduces standby losses as the DC bus can be totally disconnected from the AC mains when it does not have to operate. DC bus deactivation is simply achieved by turning off SCRs, without requiring an additional relay to open the circuit in standby. The steady-state losses are also reduced, thanks to the removal of the NTC / PTC resistor traditionally used to limit the inrush current, which in turn removes the need for a relay to bypass it.