What Is a High Voltage Generator?
A high voltage generator is a device that converts low voltage AC current received from the power company into high voltage AC or DC current.
The electricity itself transmitted from the power company is high voltage, such as 6.6kV or 33kV, but is converted to low voltage, such as 200V or 400V, for safety reasons at the end of actual use of the electricity.
When using equipment that requires high voltage for operation or conducting tests using high voltage, it is necessary to convert from such low voltage to high voltage.
There are several types of high voltage generators for different applications, each with different voltage characteristics and ranges.
The lineup varies from manufacturer to manufacturer but includes DC high voltage stabilized power supplies, withstand voltage testing/insulation breakdown devices, impulse voltage generators, high voltage pulse generators, and high voltage testing devices.
Uses of High Voltage Generators
Uses of high voltage generators vary according to the characteristics of the device, but
- Coating of various parts such as car frames and construction materials using DC high voltage
- Withstand voltage, dielectric breakdown, and impulse testing of electric wires and other industrial electrical equipment
- Surface treatment of metals, plastics, and other materials by repeatedly generating high voltages
- Sewage treatment using underwater plasma
- Lightning strike and lightning surge tests by generating simulated lightning
- High-voltage practical training and evaluation testing at technical high schools, universities, and other qualifying schools
The following is a list of examples.
Principles of High Voltage Generators
High voltage generators use electronic circuits with an amplification function, called amplification circuits, to convert low voltage to high voltage.
An amplifier circuit is an electronic circuit that produces an output signal of greater energy than the input signal and consists of a capacitor and components such as resistors and diodes.
A typical example is the Cockcroft-Walton circuit.
Cockcroft-Walton circuits are used when a relatively low-current, high-voltage power supply is required, and can create voltages as high as several 10 V to several million V.
The circuit is made up of a capacitor and a rectifier (either a bipolar vacuum tube or a semiconductor diode), and voltage amplification circuits made up of these components are stacked in a ladder-like fashion.
Because the circuit components are simple, they are lightweight and inexpensive compared to transformers.
In an amplifier circuit, when a voltage is applied, a capacitor upstream is charged to a maximum peak value of the input value.
The downstream pole plate then has a potential equal to the sum of this capacitor and the voltage of the power supply.
Because of the rectifier, no current flows through the reverse bias, and as current flows through the forward bias to the next capacitor, the next capacitor is charged to its potential.
By repeating this process, the capacitors are charged in sequence and the potential gradually increases.
Discharging in series in this state produces a high voltage output.