Patent · US Expired

Fault detector circuit with two-fault memory

US4017775A · kind A · utility

6Cited by
3References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 28, 1975
Grant dateApr 12, 1977
Priority date
Expiry dateOct 28, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02P7/29
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A fault detector circuit in a silicon controlled rectifier (SCR) control for series-connected direct-current motors in which current to the motor flows in pulses through a main SCR as the main SCR is repeatedly turned on and off. If during operation the main SCR shorts, the field winding is disconnected from the armature and maintained disconnected. If during operation the main SCR is not defective but fails to commutate, the field winding is disconnected from the armature and then reconnected thereto. If the main SCR again fails to commutate, the field winding is again disconnected from the armature and is maintained disconnected therefrom.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.