Overvoltage Protection

An overvoltage protection circuit comprising:

• first and second power input connections for connection to a rectified or DC voltage source;
• a soft-start module having:
• a soft-start module input coupled to the second power input connection,
• a soft-start module output,
• a circuit leg for soft-starting connected between the soft-start module input and the soft-start module output and comprising a resistive element, and
• a circuit leg for normal operation connected between the soft-start module input and the soft-start module output;
• a smoothing capacitance coupled to the first power input connection and the soft-start module output;
• a circuit condition determiner arranged to determine whether one or more conditions for normal operation are complied with and to cause interruption of the circuit leg for normal operation in the event that one or more of the conditions for normal operation are not complied with;
• and
• an overvoltage detector arranged to detect a voltage across at least part of the smoothing capacitance and to cause interruption of the circuit leg for soft-starting in the event that the detected voltage exceeds an excess voltage threshold.