Multiple chopping gap is always used if simple, conventional spark gaps no longer switch reliably, fast and accurate enough
Multiple Chopping gap fulfils a triple function
Chopping of Impulse Voltages
Basic load for Impulse Generator
Measurement of Impulse Voltages
Principle of Operation
Switching gap is obtained with a number of partial spark gaps connected in series.
Potential grading capacitors provide uniform voltage loads on each individual stage. In order to attenuate oscillations
resulting from a fast voltage rise or collapse, damping resistors are connected to these capacitors in series.
The firing sequence is initiated by triggering the bottom partial spark gap with an auxiliary spark. After flashover has
occurred at the first stage, an overvoltage is built up over the shunt resistor, generating nearly double stage voltage at
the second spark. The second spark gap breaks down and again over voltage develops in 3rd
rd stage and this process
continues for all other stages.