Transformer-Coupled LC Inversion Generators With Voltage-Inverted and Bipolar Output Signals

Abstract

The transformer-coupled LC-inversion generator (TCLCG) stands out due to its requirement of only one closing switch for voltage multiplication, independent of the number of stages. LTSPICE simulations and experiments have demonstrated the feasibility of two novel TCLCG circuit configurations that enable the inversion of the first half-cycle of the oscillating output voltage signal with respect to the polarity of the charging voltage, distinguishing them from conventional TCLCG designs. In the first solution, this is accomplished by modifying the wiring of the last-stage transformer. In the second solution, the first-stage transformer is modified, and an additional inductance is added at the generator output to earth ground. Here, the odd-numbered capacitors facilitate rapid voltage multiplication, while the even-numbered capacitors already have the correct inverted polarity. Consequently, the development of a bipolar TCLCG became feasible, consisting of a conventional noninverting and an inverting generator branch in parallel, both controlled by a single closing switch. A six-stage bipolar TCLCG, comprising matched three-stage noninverting and inverting generator branches with synchronized oscillation frequencies, achieved a peak differential voltage of 183 kV across a resistive load of 447 k $\Omega $ at a charging voltage of 21.6 kV. The contributions from the two generator branches summed almost perfectly, with an average loss of 1.2%. The rise time of the generator’s differential output signal was 25 ns. The achieved peak-to-peak differential voltage reached 301 kV. Potential applications include the control of symmetrically designed antennas.