The Braun tube with magnetic and electrostatic deflection.

The Braun tube with magnetic and electrostatic deflection. The Braun tube is a cathode ray tube. Electrons are emitted from a heated cathode (6.3 V.), focused (-15V.), then accelerated through a barrel anode (300 V.) and hit a flourescent screen. The beam position can be adjusted with a small centering magnet. For demonstration purposes, the beam can be deflected magnetically either with a hand-held permanent magnet or with magnetic deflection coils powered with a 0-12 VDC power supply. The beam can also be deflected electrostatically, using a high-voltage generator. This tube is reliable, but must be given a warm-up time of about 5 minutes.