Abstract: An improved multi-channel galvanometer assembly is disclosed particularly well adapted for use in such instruments as electroencephalographs and the like. The assembly includes a soft steel combination return path structure and frame supporting a plurality of galvanometer movements. The design employs pairs of samarium cobalt magnets held in place adjacent and on opposite sides of the coil of each galvanometer by magnetic attraction to the steel return path structure. The galvanometers themselves are each mounted on an aluminum support plate which also serves as a shield to prevent magnetic coupling between adjacent galvanometer coils when the galvanometers are assembled in the support frame. The galvanometers on their support plates are each individually removable and/or replaceable. The result is a lighter, smaller, multi-channel galvanometer assembly which is readily expandable and easily serviced.

Abstract: Current transformers are utilized to combine the outputs of two 30.degree. phase shifted inverters to produce a three phase output which is low in fifth and seventh harmonics. The arrangement utilizes transformers having volt-ampere ratings which are very low compared to the power output of the inverters. The circuit may also be used to convert a three phase input to a multi-phase full wave rectified output without reflecting high fifth and seventh harmonics back into the line.

Abstract: A plurality of fuses are connected in a general parallel configuration for protecting a circuit, the fuses being serially connected with inductances of varying magnitude such that steady state current may be divided equally among the fuses permitting the use of fuses of lower rating. During an overcurrent surge, substantially the entire current overload is applied to each fuse in turn so that the total elapsed time for opening the circuit is less than with fuses alone.