A power crowbar system for fast θ-pinch experiments is operated successfully. A current transformer with extremely low leakage inductance is used to reduce the effective impedance of series capacitor system. The leakage inductance of the transformer is reduced to 2 nH by employing a special arrangement of windings. It is demonstrated that a current of 40 kA, the rise time of which is 4 μsec, is maintained for 500 μsec.