Abstract: In the present invention, when a DC reactor is in a magnetically saturated state, the on/off operations of a switching element are suspended and the switching element is set to an off state for a predetermined period of time, thereby resetting the magnetic saturation of the DC reactor and maintaining the supply of power to a load. After resetting the magnetic saturation, the pulse output of the normal pulse mode is restarted.

Abstract: Disclosed herein is a sulfonamide compound represented by the formula (I): ##STR1## wherein A represents a phenyl group which may be substituted, B represents a phenyl group which may be substituted, R represents a lower alkyl group, a lower alkoxy group or a lower haloalkyl group, W represents a hydroxyl group or a halogen atom, and z represents a halogen atom, a lower alkysulfonyloxy group which may be substituted, or a phenylsulfonyloxy group which may be substituted, and a herbicidal composition containing the sulfonamide compound as an effective ingredient.

Abstract: An N-(2,3-epoxypropylene)-N-aralkylsulfonamide of formula (I): ##STR1## wherein R.sup.1 is an alkyl group, a haloalkyl group, an aralkyl group or an aryl group which may be substituted, R.sup.2 and R.sup.3, independently of each other, are a hydrogen atom or an alkyl group, R.sup.4 and R.sup.4', independently of each other, are a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R.sup.5, R.sup.6 and R.sup.7, independently of each other, are a hydrogen atom, an alkyl group, a haloalkyl group or an aryl group, and n is 0 or 1.The novel compounds have excellent herbicidal effect based on the physiological selectivity between rice plant and weeds, and have low phytotoxicity against rice plant.