Noise suppression circuit adapted for use with bifilar windings
US4132954A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 26, 1977 |
| Grant date | Jan 2, 1979 |
| Priority date | — |
| Expiry date | Aug 26, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/1252
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A noise suppression circuit adapted for use with bifilar windings such as normally present in magnetic pick-up heads. The signals from the windings are coupled to a pair of operational amplifiers having a common gain control resistor for filtering out common mode noise. The first stage amplifiers are coupled to a pair of second stage amplifiers biased at the voltage of the bifilar windings and have resistance-capacitance filter circuits. The second stage amplifiers are coupled to a third stage amplifier which transforms the signal to digital form, the remaining noise appearing as spikes in the signal. The output of this amplifier is coupled to a digital noise filter circuit which includes a one-shot multivibrator coupled to a flip-flop arranged to control the digital waveform so as to filter out the spikes, that is, to eliminate the noise in the signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.