Fire Safety Science Digital Archive

It is often necessary, as in the stabilization of electromagnetic lens systems and in the use of analogue computers, to apply to a network a current which is independent of the network impedance. One way of doing this is to apply to the load, through a very high resistance, a voltage waveform having the same time characteristic as the required current waveform. This is obviously inefficient and, is often very inconvenient as it necessitates the generation of an E.M.F. many times the potential difference developed across the load. This note describes the basic and practical designs of a circuit which will generate current waveforms with a reasonable efficiency.