Electrical breakdown in gases: building up the charge (left), is soon followed by the arc (right).
Source: Museum Victoria
When it's not in use for spectacular Lightning Room shows, the Victoria University High Voltage Theatre at Scienceworks is a practical teaching lab for the next generation of electrical engineers.
Students in the final year of their course perform high-voltage experiments on this specialised equipment that generates 100,000 volts of electricity. Much of the equipment was donated by Telstra when their research lab closed, and further assistance was provided by sponsors and a Victorian Government grant.
Ed Bondarenko is the senior technical advisor for the lab; every component within the Faraday cage is his responsibility, including the two large Tesla coils. Formerly the principal scientist at the Telstra research lab, he designed and set up the facilities. His job is to ensure it all works properly and safely, to assist with the teaching lab, and to design new displays for Lightning Room shows.
The experiments completed by VU students give them practical experience in real-life applications, such as testing the efficiency of insulators used on domestic power lines, and propagating high voltage over long distances. They also investigate electrical breakdown in gases – or what happens when an electrical charge builds up to the point that usually non-conductive substances, such as air, become conductive. In the experiment here, the charge builds up to 70,000 volts before breakdown occurs, ionising the air between the electrodes and creating an arc.
On a small scale, this principle is used in electrical devices such as car ignitions, whereas lightning is a large-scale, naturally-occurring example of electrical breakdown.