Static inverter employing an assymetrically energized inductor
First Claim
1. A static inverter comprising:
- A. input terminals for connection to a source of dc potentials,B. an inductor having;
1. a core of substantially linear magnetic material having a closed main magnetic path and including a small aperture in a segment of said path which partitions the cross-section of said main magnetic path into two branches and creates a low reluctance closed flux path,2. a primary power winding encircling the full core cross-section for generating flux around said main magnetic path,3. a feedback control winding encircling one of said branches for generating a flux around said low reluctance closed path having the same direction as said main flux in a first branch and an opposite direction in the second branch,4. a second feedback winding encircling said first branch,5. a third feedback winding encircling said second branch,C. an electrical gain element having control, common and output electrodes for intermittent energization of said inductor from said dc source,said primary power winding, said feedback control winding, and said gain element being serially connected between said dc input terminals so that normal conduction by said gain element causes flux along said main magnetic path in a first direction, storing magnetic energy, and non-conduction by said gain element causes said main flux to collapse, releasing magnetic energy and creating a high voltage surge,said second and third feedback windings being serially connected between said control and common electrodes, said second feedback winding in a sense to increase gain element conduction and said third feedback winding in a sense to decrease gain element conduction when the flux in said main magnetic path increases in said first direction and in the same sense in respect to flux encircling said low reluctance flux path, said three feedback windings forming a current transformer providing feedback in a sense to increase gain element conduction as the main flux in said first direction increases until saturation of said first branch prevents further current transformer action, said first branch saturation preventing further induction in said second feedback winding, and inducing a voltage in said third feedback winding in a sense to turn off said gain element,D. means coupled to said inductor for deriving an output when said gain element is turned on and off, andE. passive means for protecting said gain element from the inductive surge and energy released when said gain element is turned off.
0 Assignments
0 Petitions
Accused Products
Abstract
A static inverter employing an inductor and an electrical gain element for intermittent assymetric energization of the inductor from a dc source is described. Reliable intermittent operation of the gain element, typically a power transistor, is achieved by use of three feedback windings which in response to saturation of a branch of the core of the inductor but before full core saturation, discontinue regenerative feedback and then apply degenerative feedback. This turn off mechanism protects the transistor from high current stresses. Passive means are provided such as a capacitor for momentarily storing the energy or diode means for coupling the energy back to the source or to the load to protect the transistor from the high voltage surge and the energy release when current flow in the inductor is interrupted. Energy stored in the capacitor may be used for transistor commutation.
-
Citations
18 Claims
-
1. A static inverter comprising:
-
A. input terminals for connection to a source of dc potentials, B. an inductor having; 1. a core of substantially linear magnetic material having a closed main magnetic path and including a small aperture in a segment of said path which partitions the cross-section of said main magnetic path into two branches and creates a low reluctance closed flux path, 2. a primary power winding encircling the full core cross-section for generating flux around said main magnetic path, 3. a feedback control winding encircling one of said branches for generating a flux around said low reluctance closed path having the same direction as said main flux in a first branch and an opposite direction in the second branch, 4. a second feedback winding encircling said first branch, 5. a third feedback winding encircling said second branch, C. an electrical gain element having control, common and output electrodes for intermittent energization of said inductor from said dc source, said primary power winding, said feedback control winding, and said gain element being serially connected between said dc input terminals so that normal conduction by said gain element causes flux along said main magnetic path in a first direction, storing magnetic energy, and non-conduction by said gain element causes said main flux to collapse, releasing magnetic energy and creating a high voltage surge, said second and third feedback windings being serially connected between said control and common electrodes, said second feedback winding in a sense to increase gain element conduction and said third feedback winding in a sense to decrease gain element conduction when the flux in said main magnetic path increases in said first direction and in the same sense in respect to flux encircling said low reluctance flux path, said three feedback windings forming a current transformer providing feedback in a sense to increase gain element conduction as the main flux in said first direction increases until saturation of said first branch prevents further current transformer action, said first branch saturation preventing further induction in said second feedback winding, and inducing a voltage in said third feedback winding in a sense to turn off said gain element, D. means coupled to said inductor for deriving an output when said gain element is turned on and off, and E. passive means for protecting said gain element from the inductive surge and energy released when said gain element is turned off. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A static inverter comprising:
-
A. input terminals for connection to a source of dc potentials, B. an inductor having; 1. a core of substantially linear magnetic material having a closed main magnetic path and including a small aperture in a segment of said path which partitions the cross-section of said main magnetic path into two branches and creates a low reluctance closed flux path, 2. a primary power winding encircling the full core cross-section for generating flux around said main magnetic path, 3. primary and secondary feedback winding means associated with said aperture for deriving an output in one sense until a branch saturates and in another sense after branch saturation as the main flux increases in a first direction, C. an electrical gain element having control, common and output electrodes for intermittent energization of said inductor from said dc source, said primary power winding, said primary feedback winding, and said gain element being connected between said dc input terminals so that normal conduction by said gain element causes flux in said low reluctance closed path and along said main magnetic path in said first direction, storing magnetic energy, and non-conduction by said gain element causes said main flux to collapse, releasing magnetic energy and creating a high voltage source, said secondary feedback winding means being connected between said control and common electrodes in a sense to increase gain element conduction prior to said branch saturation and in a sense to decrease gain element conduction after branch saturation to turn off said gain element prior to full core saturation, D. means coupled to said inductor for deriving an output when said gain element is turned on and off, and E. passive means for protecting said gain element from the inductive surge and energy released when said gain element is turned off. - View Dependent Claims (17, 18)
-
Specification