Image Number 2 for United States Patent #RE32911.
A capacitor is charged to a high voltage, and then is discharged through a circuit comprising an analytical spark gap and first and second inductive elements, whereby the discharge current is oscillatory. The waveform of the discharge current is modified by a diode rectifier shunted across the series combination of the analytical spark gap and the second inductive element. To provide for adjustment of the waveform over a wide range, the second inductive element is adjustable in inductance. The first inductive element is also preferably adjustable in inductance. Provision may also be made for changing the capacitance of the capacitor. A reversing switch makes it possible to reverse the polarity of the diode rectifier. One or more control spark gaps may be connected in series with the analytical spark gap. An electronic switching device may be connected across one of the control spark gaps to initiate the discharge of the capacitor. Either or both of the inductive elements may be replaced with other reactances or impedances, such as transmission lines. Coupling may be provided between the inductive elements. Inductance or impedance may be provided in the diode circuit. The capacitor may be replaced with some other source of alternating current or pulses. The spark may be ignited by high voltage, developed at a radio frequency by a quarter wave line. The diode rectifier may be replaced with a silicon controlled rectifier, silicon controlled switch, or some other active element.