公开(公告)号：US3445831A

公开(公告)日：1969-05-20

申请号：US3445831D

申请日：1965-10-05

Applicant: IBM

Inventor： COOPER THOMAS S ,  NORTON DAVID E

IPC: G11C7/02 ,  G11C11/06 ,  H03K17/64 ,  G11B5/48

CPC classification number: H03K17/64 ,  G11C11/06007

公开(公告)号：US3603938A

公开(公告)日：1971-09-07

申请号：US3603938D

申请日：1969-06-30

Applicant: IBM

Inventor： COOPER THOMAS S

IPC: G11C7/02 ,  G11C11/06 ,  H03K17/62 ,  G11C7/00 ,  G11C5/02

CPC classification number: H03K17/62 ,  G11C11/06007 ,  H03K17/6221 ,  H03K17/6285

Abstract: A drive system for a magnetic core array is disclosed which employs transistor switches for selectively applying the energizing currents to the drive lines. The transistor switches are in the form of floating, nonsaturating switches of the type disclosed in U.S. Pat. No. 3,289,008. The secondary windings of power supply transformers provide the sole source of energizing current for the drive lines. This isolates the drive lines from the direct current power supplies thereby minimizing the coupling of currents from the drive lines to the sense lines. The selected transistor switches are turned on to complete series circuits through their respective drive lines prior to application of a square wave voltage pulse applied to the drive lines by the pulse or power transformers. The voltage pulse provided by the power supply transformer is removed a short time prior to the turning off of the transistors. This eliminates the transistor breakdown problem and affords a significant reduction in power consumption. Each transistor switch is used for both read and write operations. This is accomplished by providing isolation diodes which are back biased by the power supply transformers to isolate the commoned collectors and emitters of the switching transistors and thereby prevent current flow in an undesired path. There is thus afforded a substantial reduction in the number of transistors and coupling transformers required in the drive system.