When the switch is open initially, there is not much resistance, so high current flows through the inductor. The energy in the inductor is due to the magnetic fields. When the switch is closed, the impedance in the circuit increases and the current will be reduced. The magnetic field previously created will be reduced in energy to maintain the current towards the load. The polarity of the inductor will therefore be reversed and will create another voltage source in series with the input voltage supply. If the rate of switching is fast enough, the voltage will be higher than the input voltage, and this boosted voltage can be controlled by controlling the duty cycle of the switch.
Nixie display drivers also sometimes use flyback converter topology. It provides galvanic isolation between the input and the output with the help of a transformer.
About NCH6300HV HV Power Booster
NCH6300HVΒ high voltage DC-DC power booster is a compact step-up DC-DC converter. It is the updated version of the popularΒ NCH6100HVΒ byΒ Omnixie. As it is a switching converter, its efficiency is high, and heat generation is low. This converter supports input voltage from 3.7V-15V DC and converts it into an output voltage of 100V-230V DC (100mA max @170V). The output voltage is adjustable by a precise potentiometer onboard. The board can be powered by a Lithium battery or by connecting to a USB port as it supports an input voltage of as low as 3.7V. The module can be completely turned off by controlling the SHDN pin for better safety and maximum energy conservation. The boardβs output voltage and safety features are perfect for driving the retro nixie displays, as well as other displays like VFD tubes, Magic eye, etc.
Read more: NCH6300HV HIGH VOLTAGE DC-DC POWER BOOSTER FOR NIXIE DISPLAYS