Vacuum tube filament flash demonstration

Vacuum tube filament flash demonstration. A cold heater/filament of a vacuum tube has a very low resistance. The result is a huge startup current in the cold heater. The current can increase to ten times the nominal current. A large decrease of lifespan is the possible result. A solution is to limit the startup current intill the wire is warm and therefore has a much higher resistance limiting the current.

Видео Vacuum tube filament flash demonstration канала polytech_nu