Patent · US Expired

Magnetic pickup preamplifier

US4547819A · kind A · utility

5Cited by
4References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 4, 1983
Grant dateOct 15, 1985
Priority date
Expiry dateMay 4, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F3/187
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A magnetic pickup which contains both resistance and stray capacitance is terminated by a negative impedance of a kind which compensates for the stray capacitance and part of the resistance, and causes a pole to be produced at a low frequency. This results in the formation of a virtually perfect integrator. Preferably the integrator is followed by a pedestal filter for receiving the output signal of the integrator, and has a zero phase shift point at a predetermined frequency higher than the frequency of the pole and within the frequency band, and has an intermediate frequency band transfer characteristic which increases at a rate of approximately equal to the decrease in transfer characteristic of integrator.

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