Patent · US Expired

Battery impedance monitor

US5773978A · kind A · utility

222Cited by
25References
17Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 25, 1996
Grant dateJun 30, 1998
Priority date
Expiry dateOct 25, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/389
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A battery impedance monitor includes a driver section having an oscillator which produces a pulsating loading signal which controls periodic loading of the battery to produce at its output terminals a pulsating voltage component having a peak-to-peak amplitude superimposed on the DC output voltage of the battery. This pulsating voltage component is detected in a measuring section, which applies the battery output through a voltage divider to a peak detector which outputs an indicating voltage level proportional to the peak-to-peak amplitude of the pulsating output signal, this indicating level being held on a storage capacitor. The voltage divider includes a Zener diode which shifts the DC level of the battery output without affecting the amplitude of the pulsating component. The measuring section is electrically connected to the driver section only through the battery terminals, but the storage capacitor is coupled to the oscillator through a load resistor and an opto-isolator which provides a discharge path for the storage capacitor during each loading pulse, so that the detector can follow decreasing as well as increasing indicator voltage levels. A delay circuit delays applicat…

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