Excitation circuit for switching magnet - receives powerful operating pulses and low holding current from two sources switched by transistors

摘要

A short powerful current pulse is applied to the magnet winding from a first current source (24) and the magnet is held in its operating position by a lower holding current, from a second, lower voltage source (25). Currents are switched by power transistors controlled by further transistors. The power transistors are inserted between a terminal of supply sources and a point of zero potential. The other terminals of the current sources are connected to the magnet winding, whose other end is also at zero potential.