Hall effect isolation amplifier
US4616188A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1985 |
| Grant date | Oct 7, 1986 |
| Priority date | — |
| Expiry date | Jun 20, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F15/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An isolation amplifier circuit is described that utilizes a magnetic field in combination with a Hall effect device to isolate input signals and output signals. The input signal is applied to a conducting coil that produces a magnetic field in a Hall effect material through which current is flowing. Because of the Hall effect, terminals on the sides of the Hall effect material can provide a voltage difference. This voltage difference is amplified and applied to a second conducting coil. The second conducting coil is adapted to provide a magnetic field in the opposite direction from the magnetic field produced by the input signal. When the magnetic fields are identical, no difference in current flowing through the two terminals will be present. The output signal of the difference amplifier circuit will be a function of the input signal. According to a second embodiment, apparatus is included for cancelling ambient magnetic fields. A second isolation amplifier circuit is arranged to have a spatial orientation rotated 180.degree. from a first isolation amplifier. With this configuration, ambient magnetic fields will have cancelling effects. The Hall effect device can be implemented in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.