X-ray analytical instrument with improved control of detector cooling and bias supply
AssigneeOlympus Scientific Solutions Americas Inc.
InventorMarc Battyani
Life of this patent
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Abstract
Disclosed is a circuit for controlling the temperature and the bias voltage of a detector used by an X-ray analytical instrument. The circuit uses a single common reference voltage for the temperature measurement and for all the ADCs and DACs in the circuit, resulting in reduced drift and improved reproducibility of detector temperature and bias voltage. ADCs with a larger number of bits are used to produce precision values of the temperature, the bias voltage, and their respective setpoints. The setpoints are digitally varied until the precision setpoint values correspond to desired values of temperature and bias setpoints.
Claims20
A circuitry for controlling a cooling power supply providing cooling power to a cooling unit of a detector of an X-ray analyzer, the circuitry comprises:
- a thermal measurement element producing a temperature measurement of the detector and subsequently a temperature voltage,
- a pre-amplifier circuit providing a control signal for controlling the cooling power, the pre-amplifier circuit further comprises:
- a single common reference element providing a common reference voltage,
- a digital-to-analog converter (DAC) configured to produce a setpoint voltage based on a pre-determined setpoint temperature value,
- an analog-to-digital converter (ADC) configured to digitize the temperature voltage and the setpoint voltage and produce a precision setpoint value, wherein the precision setpoint value is used to produce an adjusted setpoint voltage,
- a comparator producing a differential value between the temperature voltage and the adjusted setpoint voltage wherein the differential value is used as a basis for the control signal, wherein the common reference voltage is referenced by the thermal measurement, the DAC and the ADC.
A circuitry for providing a bias voltage via a bias power supply to a detector of an X-ray analyzer, the circuitry comprises:
- a bias voltage measurement element producing a bias measurement voltage,
- a pre-amplifier circuit providing a control signal for controlling the bias power supply, the pre-amplifier circuit further comprises:
- a single common reference element providing a common reference voltage,
- a bias digital-to-analog converter (DAC) configured to produce a setpoint voltage based on a pre-determined bias setpoint value and the reference voltage,
- a bias analog-to-digital converter (ADC) configured to digitize the bias measurement voltage and the bias setpoint voltage and produce a precision bias setpoint value, wherein the precision bias setpoint value is used to produce an adjusted bias setpoint voltage,
- a comparator producing a differential value between the bias voltage and the adjusted bias setpoint voltage wherein the differential value is used as a basis for the control signal, wherein the common reference voltage is referenced by the bias DAC and the bias ADC.
Dependencies are inferred from the claim text.