Mass Spectrometer Cathode Voltage Supply Using Synchronous Rectification
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Solution Overview
Problem
Existing voltage supply devices for mass spectrometer ion sources face challenges in minimizing component count and power loss while ensuring reliable emission current generation with minimal interference.
Innovation Solution
A switched-mode power supply using a transformer with two output connections and a middle connection, where diodes and transistors are used in parallel to rectify transformer output voltages, and voltage multipliers generate DC voltage for efficient electron energy supply, eliminating the need for conventional relays and improving reliability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional rectification circuits are used in the voltage supply device, then the circuit is simple to implement, but power loss increases and efficiency decreases
Solution Approach 1:
The patent replaces conventional mechanical rectification circuits with a switched-mode power supply system using transistors as electronic switches. This substitution eliminates the need for large transformers and conventional rectifiers, significantly reducing power loss while maintaining circuit functionality through electronic control mechanisms.
Solution Approach 2:
The patent changes the operating parameters of the power supply by using high-frequency switching transistors instead of conventional low-frequency rectification. This parameter change enables the use of smaller magnetic components, reduces power loss, and improves overall efficiency while maintaining the required voltage output.
2Loss of energy
If switched-mode power supply with synchronous rectification is used, then power efficiency is improved, but component count and circuit complexity increase
Solution Approach 1:
The patent merges the rectification function into the switching transistors themselves, where the same transistors that perform switching also perform synchronous rectification. This consolidation eliminates the need for separate rectifier diodes and reduces the overall component count while maintaining high efficiency.
Solution Approach 2:
The switching transistors in the patent serve multiple functions simultaneously: they act as switches for PWM control, perform synchronous rectification, and provide voltage multiplication through the voltage multiplier circuit. This multi-functionality reduces the need for dedicated components and simplifies the overall circuit architecture.
3Reliability
If conventional relays are used to switch cathode terminals, then the circuit is simple, but reliability decreases and switching speed is slow
Solution Approach 1:
The patent replaces mechanical relays with solid-state switching transistors for cathode terminal switching. This substitution eliminates mechanical wear and contact bounce issues, significantly improving reliability and switching speed while enabling precise PWM control of the emission current.
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
The solution reduces power loss, minimizes component count, and enhances reliability by using transistors in parallel with diodes and voltage multipliers, enabling efficient electron energy supply and precise emission current regulation.
Implementation Method 1
An input voltage on the primary side is present in a switched-mode power supply on a transformer. On the secondary side, the transformer is provided with two output connections and one middle connection on the output side. Opposing, i.e. H. output voltages that are 180° out of phase with each other.
Implementation Method 2
The two output terminals of the transformer are each directly connected to a diode. The diodes serve to rectify the transformer output voltages
Implementation Method 3
In order to increase the efficiency, transistors are used in parallel with the diodes in accordance with a controlled rectifier. Exactly one transistor is connected in parallel for each of the two diodes, with the gate of one transistor being connected directly to the first output connection and the gate of the second transistor being connected directly to the other output connection of the transformer.
Implementation Method 4
According to the invention, a further DC voltage is generated from at least one of the output voltages present at the two transformer outputs with the aid of at least one voltage multiplier.
Implementation Method 5
A smoothing capacitor and a choke coil preferably form a low-pass filter between the center connection of the transformer and the source connections of the transistors
Implementation Method 6
A smoothing capacitor and a choke coil preferably form a low-pass filter between the center connection of the transformer and the source connections of the transistors
Data Source
Figure 1
Figure 2
AI summary
A simplified device for supplying voltage to the cathode of a mass spectrometer has a push-pull converter, a controlled rectifier (8, 10) being present outside the normal rectifier diodes (7, 9). The gate of the first transistor (8) is connected to the second output (30) and the gate of the second transistor (10) to the first output (32) of the transformer. A voltage supply apparatus, consisting of at least one voltage multiplier, is connected to the output of the transformer via capacitors (13, 14, 15) and supplies, inter alia, the emission current measuring apparatus.