High-voltage spark source
AssigneeFisher Scientific Company
InventorJohn A. Bernier
Life of this patent
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Abstract
A spark source circuit has a discharge circuit including reactive means connected in circuit between a capacitor and an analytical spark gap and switching means for effectively removing the capacitor from the discharge circuit after an initial flow of current through the spark gap so that the current flow through the spark gap is essentially unidirectional. At the start of the capacitor discharge, the discharge circuit is essentially of the classical RLC oscillatory discharge type; and the switching action converts the discharge circuit to essentially a classical RL discharge type circuit for the remainder of the spark discharge. The circuit is simple and efficient, permits use of ceramic capacitors, and may be housed in a sealed enclosure.
Claims18
A spark source for spectrochemical analysis comprising
- a spark gap for receiving a sample to be analyzed,
- a storage capacitor,
- a discharge circuit including reactive means connected in circuit between said capacitor and said spark gap,
- discharge control means for discharging said capacitor through said spark gap, and
- switching means for effectively removing said capacitor from said discharge circuit after a brief initial interval of current flow through said spark gap so that the current flow through said spark gap is essential unidirectional.
A high voltage spark source comprising:
- an analytical spark gap having a grounded electrode and an ungrounded electrode,
- a capacitor adapted to be discharged across said spark gap,
- said capacitor having positive and negative terminals adapted to be charged positively and negatively,
- a discharge circuit connected between said capacitor and said spark gap,
- said discharge circuit including an inductive element connected in series with said spark gap and discharge control means, and
- switching means connected across said capacitor, said switching means being conductive after an initial flow of the capacitor discharge current whereby said switching means converts said discharge circuit from essentially an RLC circuit to essentially an RL circuit.
A spark source for spectrochemical analysis comprising
- a spark gap for receiving a sample to be analyzed,
- a storage capacitor,
- reactive means connected in circuit between said capacitor and said spark gap, and
- discharge control means for discharging said capacitor through said spark gap including a plurality of semiconductor switch devices connected in series between said capacitor and said spark gap, and each said semiconductor switch device includes a controlled rectifier, voltage distributing means, and voltage breakdown means responsive to the voltage across the device for switching said controlled rectifier into conduction.
Dependencies are inferred from the claim text.