公开(公告)号：US3351341A

公开(公告)日：1967-11-07

申请号：US49982765

申请日：1965-10-21

Applicant: IBM

Inventor： MARING BLAYNE E ,  PENDY JR WILLIAM J ,  GRIMM CHARLES H ,  JOHNSON JOEL S

IPC: G06K13/14

CPC classification number: G06K13/14

公开(公告)号：US3573562A

公开(公告)日：1971-04-06

申请号：US3573562D

申请日：1967-09-08

Applicant: IBM

Inventor： HANSON CHARLES C ,  MARING BLAYNE E

IPC: G06K1/02 ,  H01F7/18 ,  H01H47/32

CPC classification number: H01F7/1877 ,  G06K1/02

Abstract: An emitter controls the setting and resetting of a latch. The amplified set output of the latch turns on a current switch. The current switch conditions the anodes of silicon controlled rectifiers. The silicon controlled rectifiers are selectively turned on through logic circuitry. The magnets are connected in the anode circuit of the silicon controlled rectifiers. The magnets are deenergized by tuning the silicon controlled rectifiers off. This is done by reverse biasing the silicon controlled rectifiers, anode to cathode, by turning the current switch off. When the current switch is turned OFF, current continues to flow through the silicon controlled rectifiers for a short time. A back e.m.f. is generated when the current in the magnet coil is decreasing. This back e.m.f. is used to turn on a transistor referenced to a particular negative potential. This transistor then provides base current for another transistor which provides a path for collapsing the fields of the magnet coils.