Multiple Chopping Gaps

 

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.