ESI Mass Spectrometer High-Voltage Power Supply Polarity Switching
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Solution Overview
Problem
Conventional high-voltage power supply devices for mass spectrometers are slow in changing the voltage value without changing polarity, particularly when decreasing, which limits the number of compounds that can be measured within a specific cycle time in MRM or SIM analyses.
Innovation Solution
A high-voltage power supply system that includes a charge release assistant section to rapidly discharge electric charges by temporarily switching the polarity during voltage changes, allowing for faster voltage stabilization and enabling more efficient MRM or SIM measurements by mimicking the polarity-switching operation, thus reducing settling time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional high-voltage power supply device using a high-voltage-resistant reed relay is used to switch polarity, then the device can achieve polarity switching, but the switching speed is slow due to mechanical switching of contact points
Solution Approach 1:
The patent replaces the mechanical reed relay switching system with an electronic switching system using FETs (Field Effect Transistors) and isolation transformers. This substitution eliminates mechanical contact points and achieves polarity switching through electronic control, dramatically increasing switching speed while reducing mechanical complexity.
Solution Approach 2:
The patent introduces isolation transformers as intermediary components between the voltage generation circuits and the output. These transformers enable electrical isolation and facilitate rapid polarity switching without requiring direct mechanical contact, serving as a mediator that resolves the contradiction between switching speed and device complexity.
2Loss of time
If the voltage value is changed without changing polarity by conventional means, then the voltage can be adjusted, but the settling time is particularly long when decreasing voltage
Solution Approach 1:
The patent applies reverse polarity switching to achieve voltage reduction. Instead of simply decreasing voltage in the conventional direction, the system switches to opposite polarity and uses the charge release assistant section to rapidly discharge accumulated charges, achieving faster voltage settling by approaching the target from the opposite direction.
Solution Approach 2:
The charge release assistant section performs preliminary discharge action before the voltage change is complete. By anticipating the need for charge discharge and initiating it early through polarity switching, the system reduces the overall settling time and enables faster progression to the next measurement cycle.
3Speed
If fast polarity switching is implemented using FETs and isolation transformers, then switching speed improves, but the complexity of the voltage generation system increases
Solution Approach 1:
The patent divides the voltage generation system into separate positive and negative voltage generation circuits, each with its own FET and isolation transformer. This segmentation allows independent optimization of each circuit and simplifies the control logic, as each circuit can be controlled separately rather than managing a single complex switching system.
Solution Approach 2:
The patent designs the positive and negative voltage generation circuits with identical structures, making them universal and interchangeable. This multi-functionality allows the same circuit design to serve both polarity requirements, reducing overall system complexity through standardization and simplifying the control mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces the settling time for voltage changes without altering polarity, enhancing the detection sensitivity and increasing the number of compounds that can be analyzed within a cycle, particularly in MRM or SIM measurements.
Implementation Method 1
a positive voltage generation circuit and a negative voltage generation circuit, each of which includes a DC-DC conversion circuit using an isolation transformer
Implementation Method 2
switch circuits consisting of FETs or similar devices
Data Source
AI summary
A high-voltage power source for applying high voltage to a nozzle of an ESI ion source includes a charge release assistant section including switch circuits and other elements for forcing electric charges accumulated at output terminals to be discharged in a polarity-switching operation, whereby the positive/negative switching of the polarity of the output voltage can be quickly performed. For example, when the voltage applied to the nozzle needs to be changed from V1 to V2 (where V1 and V2 are positive, and V1>V2), a voltage control section operates a positive voltage generation section and negative voltage generation section so as to temporarily provide a negative output voltage. After a predetermined period of time, the voltage control section operates the positive voltage generation section and negative voltage generation section so as to provide voltage V2.