Energy levels in helium using op amps, VELA and BBC Micro—the evolution of a system

Abstract

The original idea of producing a current/voltage graph on a CRO for the Teltron tube using VELA and an op. amp. was devised and reported by the first author in a VELA User Group Newsletter. The second author inspired by that report went on to devise a method in which the voltage was plotted in real time in proper units using VELA and a BBC micro. This article shows how the various ‘blocks’ solved different problems, while tracing the development of the circuitry towards the final system.