Author: claimsbot

1. Power converter, comprising: a controller circuit with at least one tuneable resonant circuit; wherein each tuneable resonant circuit of the at least one tuneable resonant circuit comprises a magnetic amplifier.
2. Power converter of claim 1, wherein each tuneable resonant circuit of the at least one tuneable resonant circuit is adapted to control the operation of a fluorescent gas discharge lamp.
3. Power converter of claim 2, further comprising: a halfbridge circuit for converting a DC input voltage into a first AC voltage, the halfbridge circuit comprising a first power semiconductor, a second power semiconductor, and a first control circuit; a first capacitor to convert a pulsating DC voltage into an AC voltage; wherein the first control circuit turns on the first and second power semiconductors periodically with equal conduction time intervals; wherein the first and the second power semiconductors are operated with a non overlap time interval of zero conduction between two consecutive conduction time intervals for a minimisation of switching losses; wherein the first AC voltage is supplied to a primary winding of a transformer for isolating the halfbridge circuit from the at least one tuneable resonant circuit; and wherein the at least one tuneable resonant circuit is connected to a second winding of the transformer.
4. Power converter of claim 3, further comprising a rectifier circuit for converting a third AC voltage into a DC output voltage, the rectifier circuit comprising: a third winding of the transformer for isolating the halfbridge circuit from the rectifier circuit; a series inductor; a plurality of series capacitors; wherein the third winding of the transformer supplies the third AC voltage to the rectifier circuit; wherein the series inductor and the plurality of series capacitors form a series resonant converter; and wherein the series resonant converter is tuned to the operation frequency of the rectifier circuit.
5. Power converter of claim 4, wherein each tuneable resonant circuit of the at least one tuneable resonant circuit is connected to the second winding and to a fourth winding of the transformer; wherein the second winding of the transformer supplies a second AC voltage with a first polarity and the fourth winding of the transformer supplies a fourth AC voltage with a second polarity; and wherein the first and second polarities are opposite.
6. Power converter of claim 4, wherein the halfbridge circuit comprises a second control circuit, and wherein the second control circuit controls the switching frequency of the halfbridge circuit as a function of the DC input voltage.
7. Power converter of claim 4, wherein the rectifier circuit comprises a full bridge diode rectifier and a series-parallel resonant circuit; wherein the series-parallel resonant circuit comprises a first inductor, a second inductor, a second capacitor, and a third capacitor; wherein the series-parallel resonant circuit is connected to the third winding of the transformer; wherein a first tuneable resonant circuit of the at least one tuneable resonant circuit provides a first frequency characteristic; wherein the rectifier circuit provides a second frequency characteristic; and wherein the first frequency characteristic and the second frequency characteristic correspond to each other.
8. Power converter of claim 7, comprising a feedback circuit, the feedback circuit comprising a third control circuit; wherein the third control circuit is adapted for adjusting the switching frequency of the halfbridge circuit in order to control the DC output voltage.
9. Power converter of claim 4, further comprising a mains rectifier circuit and a boost converter; wherein the mains rectifier circuit provides a first DC voltage to the boost converter; and wherein the boost converter provides a DC input voltage to the halfbridge circuit.
10. Liquid crystal display, the liquid crystal display comprising a power converter, the power converter comprising: a controller circuit with at least one tuneable resonant circuit; wherein each tuneable resonant circuit of the at least one tuneable resonant circuit comprises a magnetic amplifier.
11. Liquid crystal display of claim 10, further comprising: a halfbridge circuit for converting a DC input voltage into a first AC voltage, the halfbridge circuit comprising a first power semiconductor, a second power semiconductor, and a first control circuit, a first capacitor to convert a pulsating DC voltage into an AC voltage; a controller circuit with at least one tuneable resonant circuit; wherein the first control circuit turns on the first and second power semiconductors periodically with equal conduction time intervals; wherein the first and the second power semiconductors are operated with a non overlap time interval of zero conduction between two consecutive conduction time intervals for a minimisation of switching losses; wherein the first AC voltage is supplied to a primary winding of a transformer for isolating the halfbridge circuit from the at least one tuneable resonant circuit; wherein the at least one tuneable resonant circuit is connected to a second winding of the transformer; wherein each tuneable resonant circuit of the at least one tuneable resonant circuit comprises a magnetic amplifier; and wherein each tuneable resonant circuit of the at least one tuneable resonant circuit controls the operation of a fluorescent lamp.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A cargo tank comprising a water soluble barrier coating formulation coated onto an interior surface of said cargo tank, said formulation comprising:
a solvent; and
a rheological additive configured to increase the viscosity of said solvent;
wherein said formulation comprises a viscosity configured to provide temporary adhesion of said formulation to said interior surface of said cargo tank, said formulation capable of being removed from said cargo tank by rinsing said interior surface with water.
2. The cargo tank as claimed in claim 1 wherein said rheological additive is a natural gum comprising any one or a combination of the following set of:
carrageenan gum;
xanthan gum;
arabic gum;
tragacanth gum;
guar gum;
caroube gum;
pectin.
3. The cargo tank as claimed in claim 1 wherein in said rheological additive is cellulose or a cellulose derivative comprising any one or a combination of the following set of:
carboxmethyl cellulose (CMC);
hydroxyethyl cellulose (HEC);
hydrophobically modified (HEC);
methyl cellulose (MC);
methyl hydroxyethyl cellulose (MHEC);
methyl hydroxpropyl cellulose (MHPC);
ethyl hydroxyethyl cellulose (EHEC);
hydrophobically modified (EHEC) or (HM-EHEC).
4. The cargo tank as claimed in claim 1 wherein said rheological additive is an organoclay comprising any one or a selection of the following set of:
bentonite;
hectorite.
5. The cargo tank as claimed in claim 1 wherein said rheological additive is a gellant, in particular gelatine.
6. The cargo tank as claimed in claim 1 wherein said rheological additive is a starch derivative.
7. The cargo tank as claimed in claim 1 wherein said rheological additive is an associative synthetic comprising any one or a selection of the following set of:
an aqueous swellable emulsion (HASE);
a polyurethane based thickener (HEUR);
a hydrophobically modified polyether.
8. The cargo tank as claimed in claim 1 wherein said rheological additive is polyvinylalcohol.
9. The cargo tank as claimed in any preceding claim wherein said solvent is water.
10. The cargo tank as claimed in any one of claims 1 to 8 wherein said solvent is glycerol or a glycerol derivative, in particular monoethylene glycol.
11. The cargo tank as claimed in claim 1 wherein said solvent is glycerol and said rheological additive comprises any one or a selection of the following set of:
pectin;
polyvinylalcohol;
carrageenan gum;
gelatine.
12. The cargo tank as claimed in claim 11 wherein said formulation further comprises xanthan gum.
13. The cargo tank as claimed in any preceding claim wherein said cargo tank comprises zinc silicate coated onto said interior surface, said formulation configured for the temporary addesion to said zinc silicate coated interior surface.
14. The cargo tank as claimed in any one of claims 1 to 12 comprising a stainless steel interior surface, said formulation configured for the temporary adhesion to said stainless steel interior surface.
15. The cargo tank as claimed in any one of claims 1 to 12 comprising an organic based paint coated onto said interior surface, said formulation configured for the temporary adhesion to said organic based paint.
16. The cargo tank as claimed in any preceding claim wherein said formulation comprises a pH within the range 5 to 9.
17. The cargo tank as claimed in claim 14 wherein said formulation comprises a pH of 3.
18. A method of coating an interior surface of a cargo tank with a water soluble barrier coating formulation comprising:
mixing a solvent with a rheological additive configured to increase the viscosity of said solvent; and
spraying said formulation onto said interior surface of said cargo tank;
wherein said formulation is sufficiently viscous for the temporary adhesion of said formulation to said interior surface of said cargo tank.
19. The method as claimed in claim 18 further comprising the step of storing a hydrocarbon within said cargo tank.
20. The method as claimed in claim 19 further comprising:
removing said hydrocarbon from said tank; and
removing said liquid formulation from said interior surface of said cargo tank by washing said interior surface with water.
21. The method as claimed in any one of claims 18 to 20 wherein said solvent comprises glycerol and said rheological additive comprises carrageenan gum.
22. The method as claimed in any one of claims 18 to 20 wherein said solvent is water.
23. The method as claimed in any one of claims 18 to 20 wherein said solvent is glycerol or a glycerol derivative.
24. The method as claimed in claims 22 or 23 wherein said rheological additive is a natural gum comprising any one or a combination of the following set of:
carrageenan gum;
xanthan gum;
arabic gum;
tragacanth gum;
guar gum;
caroube gum;
pectin.
25. The method as claimed in claims 22 and 23 wherein said rheological additive is cellulose or a cellulose derivative comprising any one or a combination of the following set of:
carboxmethyl cellulose (CMC);
hydroxyethyl cellulose (HEC);
hydrophobically modified (HEC);
methyl cellulose (MC);
methyl hydroxyethyl cellulose (MHEC);
methyl hydroxpropyl cellulose (MHPC);
ethyl hydroxyethyl cellulose (EHEC);
hydrophobically modified (EHEC) or (HM-EHEC).
26. The method as claimed in claims 22 or 23 wherein said rheological additive is an organoclay comprising any one or a selection of the following set of:
bentonite;
hectorite.
27. The method as claimed in claims 22 or 23 wherein said rheological additive is an associative synthetic comprising any one or a selection of the following set of:
an aqueous swellable emulsion (HASIE);
a polyurethane based thickener (HEUR);
a hydrophobically modified polyether.
28. The method as claimed in claims 22 or 28 wherein said rheological additive is a gellant, in particular gelatin.
29. The method as claimed in claims 22 or 23 wherein said rheological additive is polyvinylalcohol.
30. The method as claimed in any one of claims 18 to 29 wherein said interior surface of said cargo tank is a zinc silicate interior surface.
31. The method as claimed in claim 30 further comprising the step of tailoring a pH of said formulation to be between 5 and 9.
32. The method as claimed in any one of claims 18 to 31 wherein said step of a spraying said formulation onto said interior surface comprises the use of mechanical spray means andor in particular pneumatically driven spray means.
33. The method as claimed in any one of claims 18 to 31 wherein said step of spraying said formulation onto said interior surface comprises the use of a fixed andor portable tank cleaning machine housed within a cargo vessel, the application of said formulation onto said surface comprising injection or recirculation of said formulation through a deepwell pump system housed within said cargo vessel.
34. The method as claimed in any one of claims 18 to 31 wherein said step of spraying said formulation onto said interior surface comprises manually spraying said formulation using a spray lance.
35. A method of preventing hydrocarbons from adhering to an interior surface of a cargo tank comprising:
mixing a solvent comprising at least one hydroxyl group with a rheological additive configured to increase the viscosity of said solvent;
coating said interior surface of said cargo tank with the solvent and rheological additive mixture;
storing a hydrocarbon based liquid within said cargo tank;
removing said hydrocarbon based liquid from said tank; and
removing said solvent and rheological additive mixture from said interior surface by washing said interior surface with water;
wherein hydrocarbons of said hydrocarbon based liquid are prevented from adhering to the interior surface of said cargo tank after coating said interior surface of said cargo tank with said solvent and rheological additive mixture.
36. The method as claimed in claim 35 wherein said solvent is glycerol or a glycerol derivative and said rheological additive is carrageenan gum.
37. The method as claimed in claims 35 or 36 wherein said interior surface of said cargo tank comprises a zinc silicate coating.
38. The method as claimed in claim 35 wherein said solvent is water.
39. The method as claimed in claim 35 wherein said solvent is a glycerol or a glycerol derivative.
40. The method as claimed in claims 38 or 39 wherein said rheological additive is a natural gum comprising any one or a combination of the following set of:
carrageenan gum;
xanthan gum;
arabic gum;
tragacanth gum;
guar gum;
caroube gum;
pectin.
41. The method as claimed in claims 38 or 39 wherein said rheological additive is cellulose or a cellulose derivative comprising any one or a combination of the following set of:
carboxmethyl cellulose (CMC);
hydroxyethyl cellulose (HEC);
hydrophobically modified (HEC);
methyl cellulose (MC);
methyl hydroxyethyl cellulose (MHEC);
methyl hydroxpropyl cellulose (MHPC);
ethyl hydroxyethyl cellulose (EHEC);
hydrophobically modified (EHEC) or (HM-EHEC).
42. The method as claimed in 38 and 39 wherein said rheological additive is an organoclay comprising any one or a selection of the following set of:
bentonite;
hectorite
43. The method as claimed in claims 38 or 39 wherein said rheological additive is an associative synthetic comprising any one or a selection of the following set of:
an aqueous swellable emulsion (HASIE);
a polyurethane based thickener (HEUR);
a hydrophobically modified polyether.
44. The method as claimed in claims 38 or 39 wherein said rheological additive is a gellant, in particular gelatin.
45. The method as claimed in claims 38 or 39 wherein said rheological additive is polyvinylalcohol.
46. The method as claimed in any one of claims 35 to 45 wherein the solvent and rheological additive mixture maintains a substantially liquid phase during a coating of said interior surface.
47. A cargo tank comprising a water soluble barrier coating formulation coated into an interior surface of said cargo tank, said formulation comprising:
glycerol or a glycerol derivative; and
a natural gum configured to increase the viscosity of said glycerol or said glycerol derivative.
48. A cargo tank comprising a substantially liquid formulation coated onto an interior surface of said cargo tank, said formulation being configured to prevent a hydrocarbon stored within said cargo tank adhering to said interior surface, said formulation comprising:
a water soluble solvent; and
a water soluble rheological additive configured to increase the viscosity of said solvent;
wherein said substantially liquid formulation comprises a viscosity configured to provide temporary adhesion of said formulation to said interior surface of said cargo tank during storage of said hydrocarbon within said cargo tank, said formulation capable of being removed from said cargo tank by rinsing said interior surface with water.
49. The cargo tank as claimed in claim 48 wherein said solvent is water, glycerol or a glycerol derivative.
50. The cargo tank as claimed in claim 49 wherein said rheological additive comprises at least one natural gum.
51. The cargo tank as claimed in claim 49 wherein said rheological additive comprises at least one cellulosic.
52. The cargo tank as claimed in any one of claims 48 to 51 wherein said interior surface comprises zinc silicate.

What is claimed is:

1. A high-voltage oscillator comprising:
a first normally-on switch in series with a resonant circuit;
a second normally-on switch in parallel with the resonant circuit; and
a control circuit preventing the simultaneous conduction of the two switches.
2. The oscillator of claim 1, comprising a single resonant circuit.
3. The oscillator of claim 1, wherein the control circuit has no auxiliary supply circuit.
4. The oscillator of claim 1, wherein said first switch is on during periods of recharge of a capacitor of the series resonant circuit, and is off during a resonance phase.
5. The oscillator of claim 1, wherein the control of the first switch is performed by comparing the voltage across the resonant circuit with a predetermined threshold.
6. The oscillator of claim 1, wherein the control of the second switch is performed by delaying a turn-on time of this switch with respect to an end of the conduction of the first switch.
7. The oscillator of claim 1, wherein said switches are bidirectional in current and voltage.
8. The oscillator of claim 1, wherein said switches are one-way switches.
9. The oscillator of claim 8, comprising a free wheel diode, reverse biased with respect to the second switch.
10. The oscillator of claim 9, wherein the resonance phase includes a first cycle of discharge of said capacitor through the second switch and a second cycle of discharge of said capacitor through said free wheel diode.
11. The oscillator of claim 8, wherein the second switch is formed of a thyristor having its anode connected on the side of the first switch.
12. The oscillator of claim 8, wherein the first switch is formed of an NPN-type bipolar transistor made normally on by the connection of its base and of its collector by means of a resistor, the emitter of the bipolar transistor being connected to the resonant circuit.
13. A D.C. supply circuit including the high-voltage oscillator of claim 1.
14. The D.C. supply circuit of claim 13, wherein an output capacitor is connected, in parallel with two rectifying diodes in series, to the second capacitor.
15. The supply circuit of claim 14, wherein a first rectifying diode connects one end of the resonant circuit to an electrode of the second switch and to a positive electrode of the output capacitor, the anode of the first rectifying diode being connected to the resonant circuit and to the cathode of a second rectifying diode connected to the free wheel diode.
16. The supply circuit of claim 14, wherein the biasing of the output voltage is chosen according to the electrode of the output capacitor to which is connected the reference of the supply voltage.
17. The supply circuit of claim 13, including a control circuit having the function of delaying the time of starting of the second switch according to the output voltage.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A modulated well telemetry apparatus comprising:
an electrically conductive pipe extending from above ground surface to a point below said surface inside a casing;
an electrical conductor located at a position a distance from said first electrically conductive pipe and extending from above said ground surface to a point below said surface;
modulated reflector sensor apparatus located below said surface for reflecting data on said well;
a RF transceiver located at said surface connected between said electrically conductive pipe and said electrical conductor, for transmitting a RF signal that is confined between said electrically conductive pipe and said electrical conductor to said modulated reflector sensor apparatus, and for receiving a signal modulated with well data and reflected by said modulated reflector apparatus.
2. The apparatus as described in claim 1, wherein said electrical conductor is small diameter pipe in a hole dug by water well drilling apparatus.
3. The apparatus as described in claim 1, wherein said electrical conductor is small diameter pipe in a preexisting hole located near said first electrically conductive pipe.
4. The apparatus as described in claim 1, wherein said electrical conductor is an existing nearby electrically conductive pipe.
5. The apparatus as described in claim 1, wherein said electrically conductive pipe defines a first portion and a second portion, said first and second portions being separated by an insulated portion, and said modulated reflector and sensor apparatus is connected across said insulated portion, and further comprises switching means for providing a connection between said first and second portions of said first electrically conductive pipe, and disconnecting said connection in accordance with sensor input to provide increased modulation of the signal reflected from said modulated reflector and sensor apparatus.
6. A modulated well telemetry apparatus comprising:
an electrically conductive pipe extending from above ground surface to a point below said surface inside an electrically conductive casing;
an electrical conductor located at a position a distance from said electrically conductive pipe and extending from above said ground surface to a point below said surface;
modulated reflector sensor apparatus located below said surface for reflecting data on said well;
a RF transceiver located at said surface connected between said electrically conductive pipe and said electrically conductive casing, and said electrical conductor, for transmitting a RF signal that is confined between said electrically conductive pipe and said electrically conductive casing, and said electrical conductor, and to said modulated reflector sensor apparatus, and for receiving a signal modulated with well data and reflected by said modulated reflector apparatus.
7. The apparatus as described in claim 6, wherein said electrical conductor is small diameter pipe in a hole dug by water well drilling apparatus.
8. The apparatus as described in claim 6, wherein said electrical conductor is small diameter pipe in a preexisting hole located near said electrically conductive pipe.
9. The apparatus as described in claim 6, wherein said electrical conductor is an existing nearby electrically conductive pipe.
10. The apparatus as described in claim 6, wherein said electrically conductive casing defines a first portion and a second portion, said first and second portions being separated by an insulated portion, and said modulated reflector, and sensor apparatus is connected across said insulated portion of said electrically conductive casing, and further comprises switching means for providing a connection across said insulated portion and disconnecting said connection in accordance with sensor input to provide increased modulation of the signal reflected from said modulated reflector and sensor apparatus.