Patent · US Expired

System for establishing and steering a precise current

US4163188A · kind A · utility

2Cited by
3References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 30, 1978
Grant dateJul 31, 1979
Priority date
Expiry dateMay 30, 1998

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05F1/56
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A system for establishing a precise reference current and steering the precise reference current through a load. A reference resistance is connected between a first node and a common terminal and a first reference voltage is maintained at the first node to establish a precise current flow through the reference resistance. A capacitance is connected between the source and the gate of a field effect transistor. A first switch is provided for connecting the field effect transistor in series with the reference resistance. A control loop is connected to a second node in the series circuit between the first switch and the field effect transistor and to a second reference voltage terminal. A second switch is provided for connecting the control loop to the gate of the field effect transistor; and a third switch connected to the second node is provided for connecting the field effect transistor in series with a load. When the first and second switches are closed and the third switch is open, the control loop causes the capacitance to be charged until the voltage at the second node matches the second reference voltage to thereby provide a voltage across the gate and source of the field effec…

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