| 摘要 |
<p>[Problem] To prevent, with a simple circuit configuration, an after-flash from occurring and a large surge voltage from occurring in a primary winding when opening between welding electrodes between which excitation current is flowing. [Solution] In a capacitor type welding method according to the present invention, electric charges charged on a welding capacitor are discharged and when the discharge current is brought into a state in which the discharge current does not substantially flow through a discharge switch, excitation current that has been flowing through the primary winding of a welding transformer is transferred to the secondary winding thereof. When opening between a first welding electrode and a second welding electrode while the transferred excitation current is flowing through the secondary winding, the discharge switch is brought into a state in which the discharge switch can be turned on by applying a drive signal thereto. Surge voltage occurring in the primary winding of the welding transformer when opening between the first and second welding electrodes is thereby flowed through the discharge switch to the welding capacitor as surge current.</p> |
