Water treatment regeneration system incorporating alternating current excitation and paired operational amplifiers with asymmetrical feedback elements
US4847598A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Nov 27, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/22
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A signal responsive circuit especially adapted for use in a water treatment system for signaling the need for regeneration of an ion exchange resin bed or the replacement of a particulate filter medium. A series of three electrodes are disposed in the water treatment medium in longitudinally spaced relation along the direction of flow and an alternating current signal drives the center-most electrode. The two outer electrodes are coupled as inputs to first and second operational amplifiers having asymmetrical gain characteristics. When the effective resistance between the center electrode and the two outer electrodes are equal, which is the condition prior to the movement of the hardness front or contamination front to the location of the electrodes, a first signal output condition exists. However, when the resin bed or filter medium becomes "exhausted" to the point where the hardness or contamination front moves to a point between the center and upstream electrode, the signal output condition reverses state and can be used to trigger regeneration or replacement of the medium. The use of an alternating current drive signal obviates problems relating to electrode contamination or er…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.