US4097355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water sterilization apparatus
Assignee: Sachs Systemtechnik GmbH
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Filing: 1977-06-08
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Granted: 1978-06-27
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Expires: 1997-06-08
Abstract
Abstract The electrodes of a water purification cell are immersed in the water to be sterilized. The current through the cell is kept constant by varying the resistance of an emitter-collector circuit of a transistor connected in series with the cell to compensate for changes in the cell's internal resistance. The voltage across the cell is monitored by two threshold circuits to determine if the conductivity of the water is within an allowable conductivity range. If the conductivity falls outside the range, a light-emitting diode is energized. The light-emitting diode is also energized if the voltage of the battery supplying the power for the cell falls below a given value. If no water is present in the supply line to the cell, a switching transistor is blocked, thereby disconnecting most of the equipment from one side of the battery.
Inventors
- 👤 Wolfgang Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:57
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/46; C02F1/461; C02F1/46104; G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/561; C02F1/467; C02F1/4672; C02F2201/00; C02F2201/46; C02F2201/461; C02F2201/46105; C02F2201/4612; C02F2201/46125; C02F2201/4616; C02F2201/46165; C02F2303/00; C02F2303/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
102 words
Water sterilization apparatus, comprising in combination, a water purification cell having an internal resistance varying as a function of the conductivity of water passing therethrough, said purification cell being effective only when the voltage thereacross has an amplitude in a range between a predetermined minimum amplitude and a predetermined maximum amplitude and requiring a substantially constant current for proper sterilization of said water; a constant current source connected to said water purification cell for furnishing said constant current; and monitoring means for monitoring the voltage across said water purification cell and furnishing a fault signal when said voltage is outside said range.
Claim 2
Dependent Claim
102 words
Water sterilization apparatus, comprising in combination, a water purification cell having an internal resistance varying as a function of the conductivity of water passing therethrough, said purification cell being effective only when the voltage thereacross has an amplitude in a range between a predetermined minimum amplitude and a predetermined maximum amplitude and requiring a substantially constant current for proper sterilization of said water; a constant current source connected to said water purification cell for furnishing said constant current; and monitoring means for monitoring the voltage across said water purification cell and furnishing a fault signal when said voltage is outside said range.
Claim 3
Dependent Claim
55 words
Apparatus as set forth in claim 1, wherein said monitoring means comprises a threshold circuit for furnishing a threshold output signal when said voltage across said water purification cell exceeds said predetermined maximum amplitude or is less than said predetermined minimum amplitude, and indicator means for furnishing a visual indication of said threshold output signal.
Claim 4
Dependent Claim
131 words
Apparatus as set forth in claim 2, wherein said threshold circuit means comprises a first and second series circuit each connected in parallel with said water purification cell, each comprising a Zener diode and a resistor connected to said Zener diode at a common point, and gating means having a first input connected to said common point of said first series circuit, a second input and a gating output, and an inverter connected between said second common point of said second series circuit and said second input of said gating means; and wherein said indicator means comprises a light-emitting diode, an indicator transistor having an emitter-collector circuit connected in series with said light-emitting diode and a base, and means for connecting said base to said gating output of said gating means.
Claim 5
Dependent Claim
74 words
Water sterilization apparatus comprising: (a) a cell adapted to hold the water to be purified; (b) two electrodes spacedly arranged in said cell for contact with said water; (c) constant current supply means connected to said electrodes for passing a constant current between said electrodes through said water; and (d) monitoring means for monitoring the voltage across said electrodes and for furnishing a fault signal when the monitored voltage is outside a predetermined range.
Claim 6
Dependent Claim
74 words
Water sterilization apparatus comprising: (a) a cell adapted to hold the water to be purified; (b) two electrodes spacedly arranged in said cell for contact with said water; (c) constant current supply means connected to said electrodes for passing a constant current between said electrodes through said water; and (d) monitoring means for monitoring the voltage across said electrodes and for furnishing a fault signal when the monitored voltage is outside a predetermined range.
Claim 7
Dependent Claim
64 words
Apparatus as set forth in claim 4, wherein said constant current supply means comprises a source of DC voltage, controllable resistance means interconnected between said electrodes and said source of DC voltage, and means for changing the resistance of said controllable resistance means to compensate for changes in the internal resistance of said water purification cell, thereby maintaining a constant current through said cell.
Claim 8
Dependent Claim
60 words
Apparatus as set forth in claim 5, wherein said controllable resistance means comprises the emitter-collector circuit of a transistor, said transistor further having a base, means for furnishing a control signal having an amplitude varying as a function of the amplitude of current through said emitter-collector circuit, and means for applying said control signal to said base of said transistor.
Claim 9
Dependent Claim
103 words
Apparatus as set forth in claim 6, wherein said means for furnishing a control signal comprises a resistor connected in series with said emitter-collector circuit of said transistor, the voltage drop across said resistor constituting said control signal; and wherein said means for applying said control signal to said base of said transistor comprises means for furnishing a reference voltage, a difference amplifier having a direct input, an inverting input, and an output, and means for connecting said direct input to said resistor, said inverting input to said means for furnishing a reference signal and said output to said base of said transistor.
Claim 10
Dependent Claim
24 words
Apparatus as set forth in claim 7, further comprising a feedback resistor connected between said output of said difference amplifier and said inverting input.
Claim 11
Dependent Claim
72 words
Apparatus as set forth in claim 8, wherein said resistor has a first terminal connected to said emitter-collector circuit of said transistor and a second terminal; wherein said first terminal of said resistor is connected to said direct input of said difference amplifier; and wherein said means for furnishing a reference signal comprises a Zener diode connected from said second terminal of said resistor to said inverting input of said difference amplifier.
Claim 12
Dependent Claim
59 words
Apparatus as set forth in claim 5, wherein said source of DC voltage is a battery having a positive and negative terminal; wherein said electrodes are series connected from said positive terminal to ground potential; further comprising means for connecting said negative terminal of said battery to ground potential only when water is flowing through said water purification cell.
Claim 13
Dependent Claim
79 words
Apparatus as set forth in claim 10, wherein said means for connecting said negative terminal of said battery to ground potential comprises the emitter-collector circuit of a switching transistor, said switching transistor further having a base, sensing means positioned in the intake of water to said purification cell for furnishing a switching signal only in the presence of water therein, and means for maintaining said switching transistor in the conductive state only in the presence of said switching signal.
Claim 14
Dependent Claim
39 words
Apparatus as set forth in claim 5, wherein said source of DC voltage is a battery; said monitoring means including means for furnishing a fault signal when the voltage across said battery is less than a predetermined minimum voltage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |