公开(公告)号：US3532939A

公开(公告)日：1970-10-06

申请号：US3532939D

申请日：1968-06-17

Applicant: ASEA AB

Inventor： AVIANDER STIG

IPC: H01H47/18 ,  H03K17/28 ,  H03K17/292 ,  H03K17/26

CPC classification number: H01H47/18 ,  H03K17/28 ,  H03K17/292

公开(公告)号：US3693081A

公开(公告)日：1972-09-19

申请号：US3693081D

申请日：1970-07-23

Applicant: ASEA AB

Inventor： AVIANDER STIG

IPC: H02H3/46 ,  H03K5/26 ,  G01R23/14 ,  G01R23/02

CPC classification number: H02H3/46 ,  H03K5/26

Abstract: A frequency relay for determining the deviation of a supervised frequency from a normal frequency has means for generating a signal with the supervised frequency and a second signal with a normal frequency and means for transferring said two signals into square voltages with high amplitude during one half period and low amplitude during the other half period. A logic circuit has two inputs to which said two signals are supplied and an output on which a third signal appears which has a certain amplitude when the two input signals are the same and another amplitude if the two input signals are different. A differentiating circuit has its input connected to the output of the logic circuit over a low-pass filter, the output signal of the differentiating circuit being a gauge of the deviation of the supervised frequency from the normal frequency.

公开(公告)号：US3431471A

公开(公告)日：1969-03-04

申请号：US3431471D

申请日：1966-11-04

Applicant: ASEA AB

Inventor： AVIANDER STIG

IPC: H01H47/18 ,  H03K5/13 ,  H03K17/28

CPC classification number: H03K17/28 ,  H01H47/18 ,  H03K5/13