Browse Prior Art Database

Transformer Coupled Storage Charge Removal

IP.com Disclosure Number: IPCOM000075713D
Original Publication Date: 1971-Nov-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Fugere, DG: AUTHOR [+2]

Abstract

The drawing shows two transistors 2 and 3 that are coupled by a network of transformer windings 4, 5, and 6 and diodes 7, 8, and 9. The transformer windings are coupled as the dot convention in the drawing shows. The transformers and diodes prevent transistor 3 from saturating. They also speed up the removal of charges from the base region of transistor 3 when it is turned off.

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Transformer Coupled Storage Charge Removal

The drawing shows two transistors 2 and 3 that are coupled by a network of transformer windings 4, 5, and 6 and diodes 7, 8, and 9. The transformer windings are coupled as the dot convention in the drawing shows. The transformers and diodes prevent transistor 3 from saturating. They also speed up the removal of charges from the base region of transistor 3 when it is turned off.

The arrows show the currents associated with the transformer when transistor 3 is turned on. Diode 7 prevents the collector terminal of transistor 3 from becoming more negative than the dotted end of winding 5. Diode 8 produces a small voltage difference between the dotted end of winding 5. Thus, diodes 7 and 8 cooperate to prevent the base-collector junction of transistor 3 from being forward biased, a condition called saturation which slows the operation of a transistor.

When transistor 3 is turned off, diode 9 conducts in circuit with winding 6 and removes the charge that is stored in the base region of transistor 3. This operation makes transistor 3 turn off faster.

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