60 Hz Inductor Design

60 Hz Inductor Design
Requirements: 500 μH minimum from 1 to 5 amps of 60 Hz Current.
Consider minimum current level.
For this example, the inductor must maintain 500mH minimum from 1 to 5 amperes, or down to 20% of full-rated current (I max). The importance of this consideration is illustrated by the graph above. This shows that, in the case of -40 Material, if the inductor is designed to operate at 10 kG at I max, that the inductance will be greater than or equal to L at I max down to 2.5 / 42 = 6.0% of I max. Likewise, if the inductor operates at 8 kG at I max, the inductor can only be operated down to 4.6 / 19.5 = 25% of I max before lower inductance will result.
Calculate Energy Storage Required (1/2 LI2
1/2 LI2 = (1/2) (500) (5) = 6250 μJ
Select appropriate core size.
In this example -40 Material will be used. In order to maintain a minimum inductance down to 1 amp (20% of I max), the inductor must be designed to operate at greater than 8 kG at I max. This requires a core no larger than the E137 core or T131 toroidal core. To keep temperature rise down, the T131 will be selected.
Calculate the required Energy Storage (1/2 LI2)
1/2 LI2 = (1/2) (45) (7.5)2 = 1266 μJ
Determine number of turns.
At 6250 μJ, the T131-40 indicates 235 ampere-turns.

NI = 235 N = 235 / 5 = 47 turns

Select wire size.
Since the "simple" winding results are a rough approximation of typical single-layer windings, the Single Layer Winding Table can be used as a guide in selecting the wire size. #19 will fit in a single layer and yield about 20C° temperature rise due to the winding losses.
Part no. T131-40
47 turns #19

353 West Grove Avenue, Orange, CA 92865, U.S.A.
e-mail: sales@coilws.com

© 1996 - 2011CWS ByteMark & ByteMark
All Rights Reserved

Return to last URL ByteMark Top Page Experimenter / Design Assortments Books - Valuable information Powdered Iron Components and information - Section I Ferrite Components and information - Section II Section III Section IV Power Magnetics W2FMI BALUNs, UNUNs & Kits - Section VI Price List Order Form / Link to Secure Site Suggested Reading A letter from Dr. Jerry Sevick W2FMI Index Page