PURPOSE: To eliminate any necessity of booster circuit and surely ignite a triggering element by a capacitor of small capacity.

CONSTITUTION: A capacitor Cd is parallel connected to a triggering element 12d, which is connected to a battery power supply Vb and triggers by energizing an ignition current, so as to charge to the almost same voltage as the output voltage Vbo of the battery power supply Vb. The positive charge band electrode of the capacitor Cd is grounded by the second switching element Sd2 receiving an ignition command and at the same time differential voltage (roughly 2Vbo) between the output voltage Vbo of the battery power supply Vb and a terminal voltage of the negative charge band electrode of the condenser Cd is applied on the triggering element 12d via the first switching element Sd1 so as to trigger and ignite with sufficient ignition energy. This constitution can eliminate booster circuit so as to drastically decrease manufacture cost of the whole device.