STORY

Siegfried hammers the anvil to reforge Nothung sward in the end of act one. A special effect for hammering was desired.

CHALLANGE

Sparks and fire flames need to come out every time when Siegfried hits the anvil with hammer.

SOLUTION

Bespoke pneumatic system was build to blow short burst of air into a anvil chamber filled with magnesium filings and throw them through heating elements. Ignited fillings get out thru slit in the anvil creating the sparks and fire. To trigger the effect in sync with hammering I designed and built an electronic module. The module senses hits with microphone and drives an air valve between compressor and the anvil. The module is build from 3 blocks: microphone input with passive filter, audio preamp and a flip-flop circuit. The filter rolles off all unwanted frequencies and is calculated to respond only on hammer noice. An amplified, filtered hammer sound triggers flip-flop which switch on, hold, and switch off the air valve.

 © Grzegorz Zając