Patent · US Expired

Luminescent voltage indicator circuit

US3987392A · kind A · utility

29Cited by
21References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 18, 1974
Grant dateOct 19, 1976
Priority date
Expiry dateJun 18, 1994

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M1/361
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A plurality of luminescent elements, such as light-emitting diodes, incandescent lamps or the like, are located adjacent each other, each connected to the output of a difference amplifier. The respective inputs of the difference amplifier are connected, on the one hand, to a voltage divider to have different reference voltages applied thereto and, on the other, in common to the input voltage to be sampled so that, as the voltage changes between the amplification ranges of the difference amplifiers, the output therefrom will change in accordance with input voltage so that the brightness of the respectively connected luminescent elements will also change, thus providing gradual increase in brightness of any individual element as the voltage changes. The difference amplifiers may be differentially connected operational amplifiers.

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