| CONSTRUCTION
Single conductor for each phase, wound in a single layer, to give minimum self-capacitance. Mounted onto an industry standard pinned carrier for vertical mounting onto the pcb. Covering all of the industry-standard current ratings, with extra types added at 1.5A, 2.5A, 5A, 7A, 9A, 10A, 11A, 12A & 13A.
Now with new versions added on a larger sized core to give approximately twice the inductance.
SUMMARY
Common-mode noise results from interference currents flowing from line to earth or neutral to earth. A major cause of these interference currents is leakage capacitance from direct-off-line power supply semiconductor switches to an earthed heatsink. The particular nature of this interference, from L-E and N-E but not from L-N, allows the use of phase-cancelling windings so that the line currents give no line-frequency magnetisation of the core. This allows the use of high permeability ferrite cores, to give the mH inductance needed to give effective filtering with the small values of "Y" capacitors that have to be used to meet earth-leakage current requirements. All chokes in this range are based on ferrite toroids, for low flux-leakage, and use a grade of ferrite selected to give a good hold-up of inductance and impedance with frequency.
Common-mode chokes EMC chokes |
