Apparatus for measuring RF voltage from a quadrupole in a mass spectrometer
First Claim
1. An apparatus for measuring a sinusoidal RF voltage from a quadrupole in a mass spectrometer, comprising:
- at least one rectifying diode circuit for rectifying said RF voltage of said quadrupole to produce and measure a rectified RF voltage by providing an average of the rectified RF voltage;
at least one operational amplifier configured as a current to voltage converter, a negative input of said at least one operational amplifier connected to the output of at least one diode in said at least one rectifying diode circuit, a positive input of said at least one operational amplifier at ground, and an output of said at least one operational amplifier in a feedback loop with said negative input, to continuously convert the diode current to a voltage and to reduce reverse leakage current across the at least one diode;
a second diode in the at least one rectifying circuit, the second diode connected in opposite polarity to the at least one diode; and
the at least one and the second diodes connected to the at least one operational amplifier.
3 Assignments
0 Petitions
Accused Products
Abstract
An apparatus for measuring RF voltage from a quadrupole in a mass spectrometer are provided. The apparatus comprises at least one rectifying diode circuit for rectifying the RF voltage of the quadrupole to produce a rectified RF voltage. The apparatus further comprises at least one operational amplifier configured as a current to voltage converter, a negative input of the at least one operational amplifier connected to the output of at least one diode in the at least one rectifying diode circuit, a positive input of the at least one operational amplifier at ground, and an output of the at least one operational amplifier in a feedback loop with the negative input, to reduce reverse leakage current from the at least one diode.
-
Citations
14 Claims
-
1. An apparatus for measuring a sinusoidal RF voltage from a quadrupole in a mass spectrometer, comprising:
-
at least one rectifying diode circuit for rectifying said RF voltage of said quadrupole to produce and measure a rectified RF voltage by providing an average of the rectified RF voltage; at least one operational amplifier configured as a current to voltage converter, a negative input of said at least one operational amplifier connected to the output of at least one diode in said at least one rectifying diode circuit, a positive input of said at least one operational amplifier at ground, and an output of said at least one operational amplifier in a feedback loop with said negative input, to continuously convert the diode current to a voltage and to reduce reverse leakage current across the at least one diode; a second diode in the at least one rectifying circuit, the second diode connected in opposite polarity to the at least one diode; and the at least one and the second diodes connected to the at least one operational amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for measuring sinusoidal RF voltage from a quadrupole in a mass spectrometer, comprising:
-
providing a circuit comprising; at least one rectifying diode circuit for rectifying said RF voltage of said quadrupole to produce and measure a rectified RF voltage by providing an average of the rectified RF voltage; at least one operational amplifier configured as a current to voltage converter, a negative input of said at least one operational amplifier connected to the output of at least one diode in said at least one rectifying diode circuit, a positive input of said at least one operational amplifier at ground, and an output of said at least one operational amplifier in a feedback loop with said negative input, to continuously convert the diode current to a voltage and to reduce reverse leakage current across the at least one diode; a second diode in the at least one rectifying circuit, the second diode connected in opposite polarity to the at least one diode; the at least one and the second diodes connected to the at least one operational amplifier; and measuring said RF voltage via said circuit. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
Specification