Temperature compensating adjustable ultraviolet lamp driver circuit and photoionization detector employing the driver circuit
OwnerCharles Willcox, David Jennings +1inventors
InventorsCharles Willcox, David Jennings, Christopher Fields
Life of this patent
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Abstract
A photoionization detector sensor equipped with a temperature compensating and output adjustable ultraviolet lamp driver for supplying an alternating current signal to the ultraviolet lamp effective to light the ultraviolet lamp with direct current supplied from both a first variable voltage supply circuit and a second temperature sensitive fixed voltage supply circuit, and method of standardizing output of the photoionization detector sensor by adjusting the voltage supplied to the driver by the first variable voltage supply circuit so that future reported values will more closely approximate actual values.
Claims10
A temperature compensating and output adjustable ultraviolet lamp driver for supplying an alternating current signal to the ultraviolet lamp effective to light the ultraviolet lamp, the driver comprising an oscillator driving a primary side of a transformer wherein the oscillator includes a pair of transistors configured to operate out-of-phase feeding the primary side of the transformer with (i) direct current from a first variable voltage supply circuit, and (ii) direct current from a second fixed voltage supply circuit, characterized in that the direct current from the second fixed voltage supply circuit is biased through a series of a positive temperature coefficient resistor and a primary bias resistor prior to reaching the transistors.
Dependencies are inferred from the claim text.