Protection circuit for use in a lighting circuit

A protection circuit for connection between a power input and a ground, comprising:

• a voltage clamping circuit connected to the power input and having an output node;
• and
• a discharge circuit connected between the output node and a ground, the discharge circuit comprising:
• a gas discharge tube component;
• and
• a controllable voltage triggering circuit with a triggering threshold of 850V to 1.9 kV, wherein the controllable voltage triggering circuit is in series connection with the gas discharge tube component and comprises a SiDAC component;
• wherein the controllable voltage triggering circuit is configured to conduct a first current and provide a first voltage drop in response to a first voltage difference for a hi-pot test between the power input and ground, wherein the first voltage difference is insufficient to provide a voltage across the controllable voltage triggering circuit which reaches the triggering threshold;
• and
• the gas discharge tube component is configured to become conductive in response to a second voltage difference for a surge test between the power input and ground thereby to trigger the SiDAC component such that the SiDAC component conducts a second current, greater than the first current, and break down to provide a low, second voltage drop close to zero, in response to the second voltage difference between the power input and ground which is greater than the first voltage difference and sufficient to provide a voltage across the controllable voltage triggering circuit which reaches the triggering threshold.