Surge-proof transformers

Two FEATURES in connection with recently improved transformer construction are of special interest: First, without the use of shields to neutralize ground capacity, it has been possible to build shell type transformers in which the distribution of surge voltages is substantially uniform, and which are practically non-oscillating even for the longest surges; second, a major improvement in the impulse strength of t he insulation h as been made through the elimination of creepage surfaces from the entire insulation structure.