[en] A novel circuit is used in the ohmic heating power supply system for HL-1. The wavefront of the primary current with high power is set by the discharge of capacitor banks and can be adjusted between 2 to 12 ms, and the flat top is sustained for more than 2 seconds by a DC flywheel generator set and energy storage inductor. The principle and technical characteristics of the circuit are described and the main parameters of the system are given. The effect of the circuit is discussed, according to the result of the adjustment and the primary test of the system