US Patent 7293468 Electromagnetic flowmeter

In order to attain a desired magnetic flux density, a parallel configuration of N divided magnetic circuits is formed, and accommodated on one pair of plate cores as N groups of exciting coils. According to the configuration, the burden of the magnetic coercive force which is driven by one of the magnetic circuits is reduced to 1/N. As a result, the consumption of the excitation power in each of the magnetic circuits can be reduced to (1/N)2. The total of magnetic fluxes which are obtained as a result of parallel driving of the N magnetic circuits are collected onto the single plate core.