RESISTANCE HEATING AND THERMOSTAT FOR AQUARIA

1173885 heating resistors and the thermostats for aquariums.The present invention provides AE n0 uve11 heating resistors and the thermostats employing said resistors for use in aquariums.It is known that aquariums must TREs properly heated and that the

tempêrature

intended operating must TREs maintained as constant as possible over time. To perform these operations, there is, commercially, a number of apparatuses, but known apparatus all have significant drawbacks which are translated into practice by inaccurate too large in the adjustment and control of the temperature and, consequently, by damages for fish and/or flora living in the aquarium.Thus, for example, the electric resistances for heating water aquariums are generally arranged in a glass tube. These glass layers are fragile; in addition, the transmission of heat between said resistance and water takes place via the air surrounding the resistor and glass which is an insulating material. By designing that, under these conditions " the heating of the aquarium water by said resistors I in order to maintain the temperature of said water a given value takes place under conditions which are thermally bad, on the one hand be dangerous for the user, on the other hand (because of the brittleness of the envelope).The present invention therefore provides firstly a new aquarium heater resistance, characterized in that it is constituted of a resistor itself obtained by use of conductive materials

particulaíres

made consistent and plastic or shaped by use of a hydrocarbon polymer matrix, the shaped product being rendered conductive according to a value chosen by controlled thermal destruction of said polymer hydrocarbon sensor, said resistor being coated with a thermally conductive material sealed and moldable, said material, preferably being a resin, which can @ TREs shaped by known methods.And thence perform the heating elements, and used as the base material of the conductive particles (by î173685 example metal particles and/or carbon particles) that will be dispersed in a hydrocarbon polymer. The mixture thus formed will be shaped by known methods, for example by performing a sintering. Then, the shaped material will be heated to a temperature sufficient to cause the controlled destruction of the polymer and the birth of a shaped material conductive electric power according to the desired value the technique described above for the embodiment of an electrically conductive material and being operable i0 form is known in itself, but, if this material is itself coated with a heat-exchanging and sealed plastic component compatible with the resistance thus formed, this produces a product, is highly electrically insulating from the outside, is internally having good electrical and heat thereby, according to the inventions of

utillser

in aquariums or any other application of m-type, which has never

étê

recommended.Although said electrically conductive material can be

utilísé

in this form as a heating resistor, therefore it is preferred, according to the invention, making the heating

résístance

by coating of the electrically conductive material; also the electrical insulation which can TREs realized and which is necessary to the immersing it in water heater, the method results in improved characteristics for the resistors themselves:

ãabrl

the functioning of the AIR, hence the

oxydaíon

GBP, they are less fragile and support higher working temperatures. Said coating comprises depositing on the electrical resistance shaping a compound shapeable this compound should have the following properties:- tREs sealed confectioneries water working temperatures, - it can conform to the shape that has been given the strength and, preferably, be itself shapeable,

c'est

to say take the desired external shape, - area of thermally conductive and electrically insulating TREs.The coating materials are preferably usable resins, for example epoxy or polyurethane type or polyester, desensitized conductive heat in their incorporating fillers suitable as, for example, metal oxides. Such resins, charged and thereby rendered conductive heat, are known.Thus, the heating resistors according to the invention are

constituêes

electric resistance itself and a coating of thermally conductive material, the cover being of windings have any thickness since its qualities

caloporteuses

remain sufficient cladding frame resistance cleanly i0 said exceed his operating temperatures.The interest premier heating resistors for heating aquariums resides, on the one hand, in the fact that they form a compact block sealed without interposition of air between the heating resistor proper and water and, on the other hand, in the fact that they are "moldable",

c'est

to say they can receive the widely differing forms. Thus, by this invention confectioneries, said resistors may be provided not only in tubular or parallelepiped, but also in the form of blocks similar to "rock"

utŒElisés

ornamenting aquariums or relatively thin plates disposed e.g. against the wall ' back of the aquarium.A further advantage of the new resistors, though not characteristic, is that they can be naive supplied with alternating or direct current, voltage during normal, or low voltage (6 or 12 volts), while providing the necessary calories. It was also found that the presence of carbon creates an increase in the electrical resistance value as the temperature of said resistance increases; this fact is favorable by providing a certain self heating mode using these resistances. Finally, the settling time of the electric current in this type of resistors is much higher than, for example, in wire, avoid repeated thermal shock in the cases a use pulsed (especially coupled with a thermostat) and gives them a longer life.However, the coating described above can 8tre performed also, according to the invention, about, for example, a metal wire, which may be itself

prêalablement

protected by a ceramic molding (for example) in accordance with known

procédês

; or about any other type of resistor compatible with this coating process. This provides the heating elements which, if they do not include all of the foregoing properties " can still be used in the application with aquariums, with the advantages that have been mentioned in the case of creation of resistors molded, and will be discussed further in the case of creation of apparatuses

combínés

heating and also integrally molded compact thermostat.I0 if to be achieved a thermostat,

c'est

to say a temperature regulating apparatus, i1 c0

nvient

associate the new resistors according to the invention to a device for measuring the temperature of the aquarium and/or outside temperature at each instant, and a device for the control of the

alitentation

or interrupting the resistors as a function of the measured temperature. Both types of devices exist and can TREs used with the resistors according to the invention.However, in order to realize compact thermostats and to overcome the difficulties encountered in the use of the current devices, there has been developed a controller 41

e_ectronique

operation resistors according to the invention.The principle of this controller is that the supply of the heating resistor is rallied following a mathematical function of the temperature difference between the measured temperature of the

aquarlum

and the desired temperature for said aquarium, which can fireplace is adjusted by the user if desired, per se=programmed with the construction. This function may particularly a function of

proportíonnalité

fireplace. On its side, the variable element that will be a function of said temperature difference and that will control the electronic device will TREs, for example, the power supplied to the resistance or the duration of the supply; in either case, is

controlera

thus permanently the system's power=f-

hau

FAs PGCs.The electronic devices for achieving such control of operation of the resistance in proportion to a temperature difference are in them m MES-known and hence not only will be described herein.By using such a regulation mode under the conditions described above provides a substantial advantage for the intended application, since the optimum temperature will be reached gradually

affichêe

, asymptotically, and will not in any way TREs exceeded; thus, the fish in the aquarium will only are able to undergo overheating detrimental

ã

their health. To accomplish this, in the case where the power available is limited, the type of control of the operation of the resistance in proportion to the temperature difference should be reserved i0 area where the temperature of the aquarium is relatively close to the desired temperature, what will be most often the case in normal operating conditions. When, for any reason this either, the temperature of the aquarium is far below the temperature

souhaítée

controls heating resistors should release 100% available power.The resistors may be energized by alternating current or direct current; a feature of the invention is that, when the current used is an alternating current, the power source control and the cutting off of the electrical resistance will always be performed, while the intensity of the alternating current becomes zero. This feature, that

peút

perform by means known

dlectroníques

, is important as it allows, on the one hand, increase the

longdvíté

apparatuses of the

inventlon

and ' it avoids, D." on the other hand the transmission of parasites.The electronic control means may TREs mounted and

lívrdesutílisées

resistors independently for heating and are joined thereto during the final assembly of the aquarium; but they may also advantageously be integral with these resistances or TREs linked restric-construction form a thermostat of suitable shape for use directly without special connection.A particularly desirable embodiment of the invention applied with aquariums is where a temperature measuring device is integrated with the molding of coating from the resistance. If it is positioned so as to read the internal temperature of the heating element it allows, associated with an electronic circuit cutoff, deterioration of the heating element if the latter reaches an internal temperature too high (e.g. in the event of inadvertant operation in the open air). If The I! instead is suitably thermally insulated resistors, it indicates the temperature of the water and functions as a pilot regulation (external). The coupling of two measuring elements (inner and outer) permits both the regulation and the power cutoff, preventing deterioration of the heating element while operating in the open air.I0 this security can also be obtained without using the thermal as vector information. It will be possible, for example, detect water for allowing the operation of the heating element (known method to be described by aquariums).Then, the electronic controls

elves

m-ESC can TREs embedded in a block of plastic, block that is connected or integral with the block heater resistors.Thus, according to the invention, it is possible to combine in a single or several devices integral devices for heating of an aquarium, the temperature measurements and the electronic controls. This may provide a confectioneries this (these) apparatus (e) (e) integral functional qualities (mainly sealing and securing), or decorative, complementary.The following non-limiting example illustrates the invention.It is desired to perform a keeping heater for an aquarium by operating in the following manner." In a housing made of molded epoxy (type resin mm in 2050 Emerson-to-Cul nanograms), there are disposed a é1 ectr0 n1 that ' constituted by a regulating control

chaoEneutilísant

diagram according.This

moñtage

electronics comprises, in connection with two thermistors reading, one, TL internal of the associated heater element, the other, the temperature t2 external water:eL - an electronic circuit operates to compare the temperature it with a maximum temperature

choisíe

(=70, for example), an electronic circuit c2 î173 - compare the temperature t2 with a temperature selected for the aquarium water (set by the user on a potentiometer), triabodies - a, which controls the power supply of the heating resistor.The electronic circuit c2 is designed and quality so that " when the temperature difference between the temperature measured and the abstemiously t2 selected is greater than a certain value, the resistor receives the entire heating current Io and that, when said temperature difference is less than a certain value, the resistance receives electrical pulses whose duration is proportional to the temperature difference.Further, a security

supplêmentaire

is obtained by the IC circuit for interrupting the supply of the heating element when Tl is upper confectioneries the maximum value arbitrarily admitted (in our example 70°).The electronic assembly defined above is provided with the means necessary for its power supply.The electronics in place, an epoxy resin is subsequently cast, completing the casing and transforming it into an integral object wafer from which the leads to the mains or battery and the connecting wires to the resistor and to the thermistors.The top of the housing, remains exposed, after molding, the LED that indicates the phases of the operation of the apparatus " and the axis of the adjustment potentiometer whose mobility has been protected from the molding by an O-ring that provides, furthermore the sealing of the opening. An adjustment knob completes the system.Side resistance, the construction is constructed in a pre-molded shell heat transfer epoxy type ml at 2850 Emerson-to-

CUEING

.Within this shell, are arranged two resistors and a thermistor that thermoplastic molded with m turn mth resin forming a monoblock. This thermistor measures the temperature TL. A second thermistor measures the temperature t2 is housed on the bonding wire thermostatically-heater component, with an overmold that later providing sealing.The resistances proper are themselves composed of a mixture powders comprised of:a phenolic resin -, - a carbon black powder, - a copper powder.The proportion of the various components allows the generation of a resistance value determined.One example of proportion is as follows:lo and 25% phenolic resin, 50% carbon black, 25% of copper powder.After mixing, the resulting powder is sintered under a pressure of i0 then T forming a rigid bar, which can buckle molding to increase the heat dissipation surface.After compression, the web is then cooked temperature below 200°. During this baking, the binder is destroyed to give rise to a matrix containing the ternary compound.The fin formed has become conductive and constitutes a heating element of high quality, which can be connected by two

oeíllets

copper that has taken care to arrange in the powder prior to compression.This resistance which, exclusion of air (which is the case in e molding an epoxy), can TREs used up to 170 180°à (core temperature has the further advantage that, in applying the

aquariophílíe

, see its resistance increases as the temperature rises.This phenomenon, which is operated, constitutes a autoregulation of temperature of the heating element.Embodiments of the invention at which an exclusive right of property or privilege is claimed, are defined as follows:iwherein electrical heater that can be used in an aquarium, the improvement comprising: a resistor

êlectrique

containing conductive particles mixed with a hydrocarbon polymer, this resistance has been shaping and would undergo a controlled heat treatment for

obtenírêlectrique

desired conductivity of the conductive particles and the

polymêre

; and a coating of a material electrically

isolê

, disposed around said electrical resistance, said insulating material being a thermoplastic material that is heat conductive and provides a seal coating and moldable.2l ' improvement as defined in claim 1 including a temperature measuring device and a

círcuit

cutoff reread at temperature measuring device for

empêoEher

overheating of the heating element.3l ' improvement as defined in claim 1 confectioneries

íncluantdispositíf

a for detecting the presence of water and a cut-off circuit, connected to said detection device

prêsence

water, only allowing the energization of the heating element than if it is surrounded by water.

Y