Discharge generator

A discharge generator comprising:

• a switch circuit comprising a switch connected to a direct-current power source;
• and
• a control unit configured to control on-off switching operations of the switch to thereby convert direct-current power supplied from the direct-current power source to the switch circuit into alternating-current output power, thus causing a discharge load to generate discharge based on the output power,
• wherein the control unit is configured to:
• switchably perform a continuous mode and a burst mode in accordance with determination of whether target output power as a target value of the output power is higher than predetermined discharge sustaining power,
• the continuous mode continuously performing on-off switching operations of the switch,
• the burst mode alternately performing:
• a discharge mode that performs on-off switching operations of the switch to thereby cause the discharge load to generate discharge during a discharge period;
• and
• a non-discharge mode that performs no switching operations of the switch, to thereby prevent the discharge load from generating discharge during a stop period,
• the discharge sustaining power being minimum power required for the discharge load to sustain the discharge generated by the discharge mode;
• and
• control, in the burst mode, on-off switching operations of the switch to thereby:
• cause a burst ratio to be set to a value expressed by the following equation (2):
• b=Po*/Pfs1 (2)
• where b represents the burst ratio, Po* represents the target output power, and Pfs1 represents the discharge sustaining power,
• the burst ratio being defined as a ratio of the discharge period to a burst period;
• and
• cause, in the burst mode, the switch circuit to output, as the output power, discharge start power and thereafter output the discharge sustaining power during the discharge period,
• the discharge start power being minimum power required for the discharge load to generate discharge.