Isolation transformer having monitor winding passing through primary core assemblies of primary winding

摘要

An isolation transformer, particularly for a cathode heater supply for a microwave source, has a first U-shaped secondary winding 421, comprising two parallel leg portions joined at one end thereof by a bridging portion. A primary winding 422 is located around and concentric with a portion of the bridging portion. A monitor winding passes through primary core assemblies of the primary winding. Electrical insulation 115 insulates the secondary winding from the primary winding. For a DC cathode heater supply a second U-shaped secondary winding is spaced from and aligned with the first U-shaped secondary winding and first and second smoothing chokes comprising respective core assemblies 1127, 1129 are fitted over connection leads arranged for connecting two ends of the first secondary winding to the cathode heater. Synchronised rectifiers are connected between the secondary windings and the first smoothing choke; and control means are provided for the synchronised rectifiers.