A method and an arrangement are provided for controlling phase-specific thyristors of a half-controlled network bridge. The method includes identifying continuously a thyristor to be controlled on the basis of magnitudes of supplying phase voltages, controlling the thyristor by enabling a current flow to its gate current circuit through an inductive component of a constant current regulator, which is common to all the gate current circuits. The thyristor control includes determining a magnitude of the gate current at the potential of the gate conductor in the constant current regulator, alternately switching off the voltage producing the gate current from the gate current circuit when the gate current is higher than a first predetermined limit, and switching on the voltage producing the gate current in the gate current circuit when the gate current is lower than a second predetermined limit.