Almag Ltd, the specialist wound component manufacturer based in Braintree, Essex, have released four new sets of shortform data for easy selection from their range of over 850 power conversion chokes. A novel feature is that the data allows the user to select from a wide spread of inductance values for each current rating, with the resulting inductor size easily identified. Four distinct series are available, each optimised by more than twenty years application experience to suit a variety of applications:-

WE Commercial range of psu & series-mode emc chokes offer very cost effective chokes, with 215 types rated from 0.3A to 22A.

WH Hi-Performance range of psu, emc and active pfc chokes offers optimum on-load performance for minimum size, with 230 types rated from 0.3A to 50A.

WP Hi-Power range of psu, emc and active pfc chokes offers maximum inductance stability, with 384 types going from 1A all the way up to 95A.

WKF Switching Regulator range, newly released, uses the newest low loss core materials to offer lower profile and higher efficiency with the latest generation of high frequency chips. 29 types go from 1A to 10A.

Low flux-leakage is a feature of all of these ranges, made possible by the use of distributed-gap powder toroidal cores.

Emc MAGNETICS DESIGN AID

To help designers to find their way through the intricacies of common-mode and  series-mode interference and suppression, specialist wound component manufacturers Almag have released a new technical data sheet based on a paper originally presented at an IEE colloquium.

"Interference Suppression – an Introduction" offers an explanation of the two basic types of interference that need to be considered, and offers an understanding of the two very different types of circuit that are needed to provide suppression.

As both common-mode and series-mode noise are present in many types of equipment, combined suppression circuits are then shown, including a cost-effective way of using common-mode choke leakage inductance to provide a measure of series-mode suppression simply by the addition of two capacitors.

Included is an explanation of the differences between common-mode and series-mode choke construction, with a review of the constraints on the types of magnetic core that can be used.

EASY SELECTION OF emc CHOKES TO 85 AMPS

Almag Ltd have released shortform data for their expanded range of UK produced common-mode and series-mode interference suppression chokes.

To ease selection of the best choke for each application a wide spread of inductance values is listed for each current rating, with the resulting inductor size clearly identified.

Three distinct series of chokes are covered, each optimised by more than twenty years application experience to suit a variety of uses, including on-board filtering to replace packaged filters initially retrofitted to meet European emc requirements.

WB single-phase common-mode range offers more than 70 types rated from  2 amps to 26 amps, and many types are vertically base mounted as standard for minimum footprint and easy installation.

WT three-phase common-mode range has over 60 types, rated from 2.5A to 26A.

WD series-mode suppression range contains no less than 328 types, rated from 0.7A all the way to 85A. For each current rating a choice of inductance values is offered, allowing the selection of compact chokes for general emc filtering, or high inductance chokes for phase-angle control circuit suppression.

Low flux leakage is a feature of all of these ranges, realised by the use of toroidal ferrite cores or distributed gap powder cores.