DE2235671A1 - GAS COMBUSTION CONTROL DEVICE - Google Patents

Description

Gas combustion control device

The present invention relates to a gas combustion control device to control the heating output of a. Gas burner preferably by regulating the gas flow rate in Relation to load fluctuation or change.

In conventional gas incinerators, for example a gas combustion water heater for hot water heating, is a device for opening and closing a solenoid or magnet installed in a gas supply line

vii / z 209884/1069

nan wtio tent «v ^ nmnMi kkjstamtatent mmm raa es a« se> itto

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net valve according to the temperature ;; the circulation ■ the ext iri iteii Wa33ers provided, or iat 3touerun sur ^means?!? e> ines in a Jasveraorgun ^ aleitun ;; "In ^ eaetsten proportional position solenoid valve corresponding to the change in resistance of a temperature-variable resistor arranged in a warm waaaerversorcuncaloitunc to determine the temperature reduction of the circulating exp 1 control the change in the control. With the control device for the 3teueruni; Switching the solenoid valve on and off stops the combustion when the temperature of the circulating hot water rises above a predetermined value; combustion is restarted when the temperature drops below the predetermined value. The disadvantage here is that the temperature of the circulating heated water changes constantly and that the solenoid valve is very susceptible to damage, since the switching on and off processes are repeated cyclically very frequently.

In the last-mentioned control device, in which the proportional-poeitions-oolenoidventil is used, the gas supply from the gas burner is controlled according to the specification controlled in such a way that the aforementioned problems occur the temperature finding and as a result of damage to the Electromagnet3 can be avoided. But there are new ones Difficulties due to the incineration properties of the Gas burner and due to the construction of the proportional

BATH ORIGINAL

Solenoid valve set. In general there is a flow the gas from the gas nozzle into the air-gas mixture control device -

in such a way that the primary air enters the air-gas mixture control einrichtung is sucked under the suction of the gas and mixed with the gas. There are no difficulties here, when gas is supplied in a relatively large amount; but if the gas supply corresponds to the decrease in load becomes gradually smaller, the kinetic energy of the gas also becomes smaller, so that the in the air / gas mixture control device the amount of primary air sucked in decreases; this then results in flashback. The flashback generally depends on the size of the gas burner and is caused when the amount of gas is decreased to one-half to one-third of the maximum gas supply amount.

In the control device in which the proportional solenoid valve is used, the plunger holder presents difficulties. In the conventional solenoid valve, the plunger is generally held by a holding part in such a way that there is friction between the plunger and the holding part occurs. In the proportional solenoid valve, the plunger core is controlled by controlling the excitation current supplied to the solenoid moved according to the change in load. shifted so that the distance between a valve seat and a valve can be adjusted accordingly «The distance between the valve and the valve seat is generally in the On the order of 3 to 5 ram, so even a minor one

209 884/1060 " ^h ~

A change in the distance causes a large change in the gas flow rate or the gas flow rate, i.e. the amount of gas supplied to the gas burner. The one exerted on the diving core Frictional force consequently causes an error in the control of the distance between the valve and the valve seat; this then results in poor control of the Gas throughput according to the change in load.

In the present invention, the aforementioned and other difficulties encountered in the known control devices of the type described are eliminated in that the current supplied to the solenoid of the proportional solenoid valve is electronically interrupted and the plunger is held by leaf springs.

In the present invention, therefore, the difficulties of flashback and gas loss are caused by detecting the temperature of the fluid circulating and heated by a gas burner by means of a temperature sensor Resistance, for example a thermistor or thermistor, and by controlling the excitation current to be supplied to the proportional solenoid valve in accordance with the change in resistance of the eliminates temperature-variable resistance in such a way that the excitation current can be interrupted when it falls below drops to a predetermined level.

The object of the invention can be designed so that created an electronic gas combustion control device

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not
fen, which supplies gas in large quantities, when the gas burner is re-ignited, but which gradually increases the gas supply for a short time from zero in order to prevent the sound of the explosion when the gas burner is ignited.

Furthermore, the subject matter of the invention can be designed in such a way that that an improved proportional solenoid valve has been created in which one fitted in a solenoid or a coil Plunger core is held by a pair of leaf springs, which eliminates the frictional force exerted on the piston and a precise control of the gas throughput or the gas flow rate is achieved.

Furthermore, according to the invention, an improved proportion- nal solenoid valve can be created in which a plunger core is held by a pair of leaf springs so that the solenoid .ventil does not become so great, and that the deflection of the leaf springs at their fixed ends can be increased, whereby a lateral displacement of the plunger core 3 from the Axis of its vertical movement is prevented. The object The invention can also be designed so that an improved Proportional solenoid valve is created in which a plunger core is held by a leaf spring or springs, which run from the free end of a leaf spring to the other end, at which it is attached to a stationary toilet lot; As a result, a lateral displacement of the plunger out of the axial direction of its vertical movement is even more reliable prevented.

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The invention thus creates a device in which the amount of fuel gas to be supplied to a gas burner is controlled by a proportional solenoid valve; this is a first A control circuit is provided which controls the excitation current to be supplied to the solenoid of the valve in accordance with the temperature change of a medium heated by the gas burner, in order to control the fuel gas supply, and a second one Control circuit provided. .-, - which determines the greetings of the excitation currents and a sudden change la outputs » current of the first control circuit after the gas * burner is ignited, and when the gas burner is extinguished,

* thereby causing a sudden change in the gas supply to the Gas burner causes.

The invention is explained in more detail below with reference to preferred exemplary embodiments, for which reference is made to the attached Drawings is referred to. Show it:

Pig.l a. Gas combustion water heater for a Hot water heating on which a gas combustion Control device is attached according to the invention;

2 shows a sectional view of a proportional solenoid valve which is built into the gas combustion control device according to the invention;

3 shows a perspective view showing a / plunger core support;

Flg. *! a perspective view of a modification of a Plunger core according to the invention;

2 0 9 0 Ö A / 1 0 8 9 .. 7 -

FIG. 5 shows a sectional illustration along the line V = V in FIG.

6 shows a perspective illustration of a further modification of a Tauchkernhai tenmg according to the Er-! finding;

7 shows a sectional view along the "line VII-VII of the Fig. 6;

FIG. 8 d η circuit diagram of an electronic control unit of the gas combustion regulating device according to FIG Invention; and

^ ig.9 an illustration of the relationship between the means of a temperature-sensitive resistor detected - th temperature of the hot water and the excitation current supplied to the solenoid of the proportional solenoid valve.

In FIGS. 1, 2 and 3, a heat exchanger 3 is connected to a radiator (not shown) via a main supply hot water line 1, via which hot water is circulated by means of a circulating pump k . Hot water at a low temperature is returned via a main return line la, heated by means of the heat exchanger 3 and supplied via a supply line ib. A gas nozzle 5 is adjacent to one end 2b of a gas-air mixture control unit

/ arranged direction 2a of a gas burner 2 in the V / eise that if gas When the nozzle 5 flows out, the primary air flows into the gas-air mixture .sclmngs control device 2a can be sucked under the suction of the gas. The gas and primary air are in a predetermined ratio in the control device 2a

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mixed and the gas-air mixture flows out of the nozzles of the gas burner 2 for combustion. A gas regulator 7 and a PrO ₇ O proportional solenoid valve are inserted into a gas line 6 which connects the gas nozzle 5 to a gas supply source (not shown).

The structure of the solenoid valve 8 is shown in detail in FIG. A bobbin 10 carrying a bobbin 9 is arranged between an upper and a lower yoke 11 and ila with spacers 12 and 12a in between. Support or holding parts 13 and 13a are away from the yokes 11 and 11a, as best shown in Figure 3. A plunger core ik with an extension 15 'which is made of non-magnetic material and has a diameter that is smaller than that of plunger core 14 is inserted displaceably into a bore in bobbin 10. The coil body 10 and its associated components are all enclosed by a housing 16. The base part or base part of a U-shaped leaf spring is firmly attached to the support part 13 projecting away from the yoke ii; the front ends of the legs of the U-shaped leaf spring 17 are pivotable by means of pivot pins l ^; * a attached to the upper part of the plunger Ik. The front ends of the legs of a U-fönnigen leaf spring 17a is also pivotally attached to the extension 15 of the plunger Ik by means of pivots 14b, the base part of the leaf spring 17a is fixed to the ^l free end of an adjusting plate 18, whose other end is fixed to that of dera lower yoke 11a protruding ITalteil 13a is attached. The diving core Ik is therefore of the

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both upper and lower U-shaped leaf springs 17 and 17a held so that the friction between the plunger 14 and the Spulenköipqr.lO can be prevented; the forces of the leaf springs 17 and 17a are used as deceleration forces which act on the rope core Ik when the coil 9 is energized.

The adjusting plate 18 is provided to adjust the strength of the leaf spring 17a. In particular, an adjusting screw 19 at the free end of the adjusting plate 18 can be loosened or tightened in order to thereby move the free end of the adjusting plate 18 towards or away from the yoke; this changes the initial deflection of the leaf spring 17a and thus its restoring or counter force. The spring force adjustment plate 18 is used to influence different properties. compensate fenheit of the leaf springs 17 and 17a as a result of dimensional errors, and other factors of the leaf springs 17 and / 17a and the coil 9 _ _{f is} the uniform or smooth motion of the plunger 1-4 adversely.

A partition or cover 20 covers the top opening the housing 16 from; the upper part of the immersion core i't that extends through the center of the cutting disk 20 sealed by means of a diaphragm oder.einer membrane 21.

A connecting part 22 has terminals 23 and 2k for connection

/ 25 of the gas line 6; In a passage between the connections 23 and 2k a Vontilsitz 26 is formed, on a valve 27 rests on the upper end of the plunger

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Ik is attached. A seal 28 is arranged between the cover 20 and the connecting part 22. Lines 29 extend from coil 9 through housing 16.

In Fig.l is a thermistor encapsulated in a protective tube 31 or NTC thermistor 30 used in the Huaptversorgungsleitung Ib and coupled to the coil 9 via an electrical control unit 32.

The operation of the device is described below. First, the circulation pump k is switched on so that hot water is circulated; the temperature of the hot water flowing through the main supply line Ib is low because the hot water is not sufficiently heated by the heat exchanger 3. The resistance of the thermistor 30 is therefore so high that the control unit 32 is actuated in such a way that the maximum current flows through the coil 9 in the solenoid valve 0, on which the principle underlying the invention is based, which will be described in detail later. The plunger core is therefore moved (downwards in FIG. 2) over the maximum distance against the leaf springs 17 and 17a until the force moving the plunger core is in equilibrium with the forces of the leaf springs 17 and 17a such that the valve 27 is removed from the valve seat 26 falls in love. As a result, the maximum gas-air mixture is supplied to the gas burner 2 for a maximum burn. This maximum combustion can be maintained as long as the heating load is equal to or higher than the heat generated during the maximum combustion.

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As the load decreases, the hot water flowing through the main supply line has such a high temperature that the resistance of the thermistor 30 becomes smaller. The control unit 32 then causes the electric current flowing through the coil or the solenoid 9 to decrease accordingly. As a result, the TauchUer-n Ik in Figure 2 due to the force of the Fedez'n 17 and 17a is moved upwards so that the valve 27 is now closer to the valve seat 26. The gas passage 25 is now throttled so that the gas burner 2 the amount of gas supplied is correspondingly lower.

From the preceding description it can be seen that the Gas supply to the gas burner 2 by means of the solenoid valve 8 in relation to the change or fluctuation in the nuisance is controlled that the temperature of the main supply line Ib flowing Waruu water regardless of the loading

/ the same change or fluctuation in load are kept at value can. According to a feature of the present invention, when the gas heating power is less than a predetermined one

Value, or when the gas supply falls below a predetermined If the value is throttled or decreased, the solenoid valve is activated 8 actuated and the gas passage 25 closed; through this is.a Flamiiienrückclcsclil agen unterijundon. If then there Gas burner is ignited again, the gas supply for for a short time it gradually closes again, un the undesirable yerbrcnluings-ο de j- ZüiidgerMuKCh, what in detail will be described later.

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The most important mechanical components of the electromagnet 8 are the devices holding or carrying the plunger core 14; the holding or carrying devices are therefore described in detail below. The holding devices of the leaf springs 17 and 17a hold the plunger. Ik so that the latter does not come into contact with the bobbin IO. There is therefore no friction between the plunger core 14 and the coil core 10. Furthermore, the fine and sensitive adjustment of the distance between the valve seat 26 and the valve 27 can be carried out in a simple but very reliable manner. Since the restoring force can be applied to the plunger Ik by means of the leaf springs 17 and 17a, no further spring or something similar is required. This represents a further advantage of the mechanical structure of the present invention. Preferably, the lengths of the leaf springs 17 and 17a are longer for the following reason. The front ends of the U-shaped leaf springs 17 and 17a follow not only the axial displacement of the plunger Ik, but also its lateral displacement. The longer the leaf springs 17 and 17a, the smaller the lateral displacement, so that the change in distance between the coil body 10 and the plunger Ik can be reduced to a minimum. Pole-wise, a uniform magnetic force distribution can also be achieved in such a way that the plunger core Ik can be displaced more reliably and more precisely.

But if the lengths of the leaf springs 17 and i7a are too great, the solenoid valve 8 inevitably becomes quite large. Which he-

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Finding therefore continues to create a facility for this too Difficulty to overcome.

In FIGS. 4 and 5, a U-shaped leaf spring 33 similar to that shown in FIG. 3 is used. The plunger core 14 is arranged between the legs 33a and 33h of the leaf spring 33; a pin 34 extends between the free ends of the legs 33a and 33b. The plunger core 14 consists of an upper and a lower part; the root part or one end of an arm 36 is arranged between the upper and lower parts of the plunger 14 and is fixedly attached to the lower part by means of a screw 35, as shown in FIG. The front end of the arm 36 is pivoted about the pin Jk. The plunger Ik is thus held indirectly by means of the leaf spring 33 en the free ends of the legs 33a and 33b. Opposite the leaf spring 17 shown in FIG. holds the plunger core 14 between the legs 33.ä and 33b of the U-shaped leaf spring 33 so that the Lan-. gene of the leaf spring can be increased without the size of the solenoid valve 8 becomes larger, Venn the leaf spring 33 is used to Hilten the plunger 14, the lateral displacement can be further reduced to a minimum so that the deviation of the axis of the plunger 14 from the the center piping of the bobbin 10 can be a minimum.

On the basis of FIGS. 6 and 7, another one, the immersion core, is shown.

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tande device according to the invention described. In this embodiment, the first leaf spring is a rectangular «, frame-shaped leaf spring 37 used; the plunger 14 extends through the opening of the leaf spring 37, as in FIG shown 1st. The second leaf spring is a U-shaped one Leaf spring 38 is provided from one side of the leaf spring 37 sticks away; Shape the free ends of the legs of the U-shape Leaf springs 38 are attached to the plunger core 14 by means of this protruding pins 39 pivotably arranged. The other side, which is opposite the side from which the U-shaped leaf spring 38 extends is so firmly attached to the holding part, that the leaf spring 37 swings in the direction indicated by the arrow a in Figure 7 when the core 14 moves in the vertical direction; the U-shaped spring 38 swings in the direction indicated by arrow b. In other words, the. Leaf springs 37 and 38 swing in opposite directions, so that the lateral displacement of the leaf spring 38 can be canceled by the lateral displacement of the leaf spring 37 can. The plunger 14 can therefore be displaced in the vertical direction coaxially to the central bore of the coil former 10 will.

The control unit 32 in the following is based on FIG individually described. A power source 40 and a switch are connected in series with the primary winding of a transformer. The secondary winding of transformer 42 is to the AC input terminals of a diode bridge turned on. One end of a resistor 44 is connected to the

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The negative or negative output connection of the diode bridge, 43 connected while the other end to one side of one Capacitor 45 is connected, the other side of which is connected to a positive output terminal of the diode bridge 43 is connected. A series circuit of a resistor 46 and a Zener diode 47 is connected in parallel with the capacitor 45. One Series connection of resistors 48, 49 and 50 is parallel connected to the Zener diode 47. Similarly, there are two further series connections, one of which consists of a resistor 51, a variable resistor 52 and the thermistor or thermistor 30, and the other of which is made up of the resistors 53 and 54. · in parallel with the zener diode 47 switched. The emitter of a transistor 55, which is a second active element, is connected to the connection connected between resistors 48 and 49; the base of transistor 55 is a wiper of the variable Resistor 52 connected. The collector of transistor 55 is with the connection line between the base of a transistor 56, which is a first active element, and a Resistor 57 connected. The other side of the resistor 57 and one side of a resistor 58 are connected to the connection line between the resistor 44 and the capacitor 45. The other side of resistor 58 is with the emitter of transistor 56 connected. The collector of the transistor 56 is connected in parallel to a connecting line from a diode 59 * the solenoid or the coil 9 of the electro Solenoid valve 8 and two series resistors 60 and 61 connected; is the other connecting line of the parallel connection

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connected to the positive output terminal of the diode bridge 43. The resistor 60 is a variable resistor, the loop of which is connected via a resistor 62 to the base of a

/a

Resistor 63, which is the third active clement, connected. A capacitor 64 is between the base of the transistor 63 and the positive output terminal of the diode bridge 43 are used. The emitter of the transistor 63 is connected to the connection line between the resistors 53 and 54. Of the The collector is connected to the connection line between the resistors 49 and 50 via a resistor 65. The through a circuit part framed by dashed line X represents the first control circuit and the circuit part framed by dashed line Y represents the second control circuit represent.

The operation of the control unit will now be described. When the switch ki is closed, so that the usual voltage is impressed across the primary winding of the transformer 42, a low voltage is induced on the secondary winding. The induced alternating voltage is rectified by the diode bridge 43, and the direct voltage is applied to the capacitor 45. The resistor 44 is used to limit the peak current when the switch 41 is closed, whereby the diode bridge 43 can be protected from damage. The current flows through the Zener diode 47 and the resistor 46. In this case, even if the current flowing through the resistor 46 changes, the voltage impressed on the three series circuits remains.

209884/1069 _ _1? .

tion from the resistors 53 and 54, the second from the resistors 48, 49 and 50 and the third from the resistor 51, the variable resistor 52 and the thermistor 50 be, because of the Zener diode 4? unchanged. Even if the remaining voltage changes, the voltage impressed on the three series connections remains unchanged. The resistors 48, 49 and 50, the resistor 5i _t ^ ^he variable resistor 52 and the thermistor 30 constitute the arms of a bridge in which the emitter and the base of the transistor 55 are connected to the connecting lines between the arms of the bridge.

When the water heater is switched on, cold water flows through the main supply line i, so that the resistance of the thermistor 30 inserted into the main supply line t is high. As a result, the base potential at the transistor 55 is then lower than its emitter potential, so that the transistor 55 becomes conductive. The current then flows from the collector of the transistor 55 to the base of the transistor and the resistor 57. As a result, the transistor 56 becomes conductive so that current flows through the resistor 58, the emitter and the collector of the transistor 56 to the coil 9. In this case, the current flowing through the coil 9 is a maximum, so that the solenoid valve is fully opened. The heating power and gas supply ^de s gas burner 2 is a maximum then.

When the load becomes so smaller that the temperature

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of the hot water increases, the resistance of the thermistor decreases 30 gradually decreases. When the base potential of the transistor 55 becomes equal to the emitter potential, the transistor 55 of the Saturation range shifted into the active range in such a way that the collector current gradually decreases. When the collector current of transistor 55 becomes smaller, transistor 56 is shifted from the saturation region into the active region in such a way that that the current flowing through the coil 9 becomes smaller. When the current flowing through the coil 9 becomes smaller, the opening of the solenoid valve 8 is reduced so that the gas supply is controlled until the heating power is in equilibrium with the smaller load. The temperature of the hot water depends on the voltage, in which the emitter potential of the transistor 55 is substantially equal to the base potential. Since the emitter potential but is almost constant, the temperature of the Waruiwas-

sers on the position of the loop thread of the variable resistance 52 from. Especially when the grinding arm of the changeable Resistance 52 is in a position which is above the position shown in Figure 8 is the temperature the hot water is relatively high; but if the sliding arm is in a position which is below the position shown in Figure 8, the temperature is proportionate low. The temperature of the hot water can therefore be as desired to get voted. An uneven texture of the thermistor 30 can therefore by means of the variable resistor 52 been compensated. .

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When the load is small, the gas supply is controlled in such a way that that a corresponding combustion rate in the gas burner 2 is maintained. The flow devices * However, the speed of the gas cannot fall below a predetermined one Levels are reduced as flashback occurs when the flow velocity drops from one-half to one-third the maximum gas flow rate is reduced.

With the water heiser> where the heating output is controlled according to the load fluctuation or change is, therefore, the gas supply must be interrupted when the G. ^ flow rate is less than a predetermined one Value will. In the control circuit shown in Figure 8, the gas flow rate by means of the Coil 9 flowing current can be determined.

When the load becomes smaller, the temperature of the hot water rises so that the gas supply line in the above-described Way is controlled. When the gas flow priority velocity for example half the maximum flow velocity, the voltage between the Points a and b in Pig.8 and the voltage at points a and c is the same, so that the transistor 63 is conductive will. The current flows through resistor 65 and resistor 50, which are one arm of the temperature sensing bridge. As a result, the transistor 55 becomes in reverse direction, so that the collision current of the transistor 55 is reduced. The collector current of the transistor 56, which is the excitation current for the coil 9, becomes

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accordingly reduced. The reduction in the collector current j

of the resistor 56 is sensed by means of the transistors 63 and 55, whereupon the current flowing through the coil 9 is immediately interrupted. In the case of the permissible or non-hazardous [

■■> Oassufuhrgeschwindigkeit the gas burner 2 of the transit ^is:

sistor 63 operated in the reverse direction, so that the change in '

current flowing through the coil 9 which fixes the temperature

setting bridge circuit not affected. The resistance ι

62 is used to limit the current, and the capacitor 64

i serves to prevent wild or parasitic oscillators'

When the solenoid valve 9 is completely closed, so

In Fig. 9 is the relationship between the temperature of the warning-
water and the current flowing through the coil 9.

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that the combustion is interrupted, the temperature of the

f Warm water slowly decreases and with it the resistance of the

Thermistor 30 gradually larger. The transistor 55 is operated likewise ί bo as the transistor 56 in the forward direction. As \

As a result, the transistor 63 is operated in the reverse direction

ben. This is sensed by the transistor 55, so that the last j

terer is instantaneously conductive, while the transistor 63
is switched off . The solenoid valve β is then wide open; so that the combustion is started again. When the temperature (rose door of the hot water, the solenoid valve 8 J

operated in the manner described above to control the optimal gas flow rate.

At point A, the burning rate becomes half the maximum speed so that the solenoid valve 8 is closed. At point B the flowing through the coil 9 increases Power on very quickly and the solenoid valve 8 is wide open.

In the circuit arrangement shown in Figure 8, the adverse effect of the conductive transistor 63 on the non-conductive transistor 55, d <r causes the same to become conductive, can be eliminated when the resistance value of resistor 62 is increased and the resistance value of the resistor 50 is smaller than that of the resistor 49. In this case, there is the point B in Fig. 9 is relatively higher Location. With the opposite conditions, however, point B is in a lower position. ,

If point B is chosen so that it lies above the point in which the solenoid valve 8 is opened, the gas supply gradually increases from zero when the gas burner as the is ignited. This setting is advantageous because the gas burner can be ignited when the gas flow rate is still low while then the gas velocity can be enlarged very quickly. With this so-called "slow ignition", the ignition can be started very smoothly, without an explosion sound occurring. The Z & it, while which the gas flow rate changes is a function of the speed of teinporaturation and of the Gain of the control circuit. 1 / cnn'die in "connecting

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The control unit described with FIG. 8 is used the flashback can be prevented and the ignition can be started very smoothly.

So far, the present invention has been described as for a water heater operated by gas combustion used for hot water heating; Of course, the present invention can also be used for one Gas oven can be used.

P at en t addresses:

209884/1069

Claims (1)

Patent a.jn s ρ r ti c h e Gas combustion control device, ¹¹ ® ^ ** "** the amount of fuel gas to be supplied to a gas burner is controlled by means of a proportional solenoid valve, thereby leaning that a first control circuit has a bridge circuit with a temperature-variable resistor (30) for determining one of the medium heated to the gas burner (2) as a bridge arm, the control circuit controlling the excitation current flowing through the solenoid (9) of the solenoid valve (8) in order to thereby increase the amount of fuel gas to be supplied to the gas burner (2) in accordance with the change in resistance of the temperature-variable resistor (30) to control, and that a second control circuit for detecting the magnitude of the current flowing through the solenoid (9) of the solenoid valve (8) is provided such that, when the current decreases below a predetermined level, the output current of the bridge circuit is controllable so that the current flowing through the solenoid (9) of the solenoid valve (8) is below vomiting. 2. £ ^ _n direction according to claim 1, characterized in that the output circuit of the second control circuit for controlling the output current of the bridge circuit with an Ana of the bridge circuit is connected in such a way that when current through the solenoid (9) of the solenoid valve (β) flows, the unbalanced state of the bridge circuit can be changed by the output route, thereby making it very fast 209884 / 10GÖ -24- - 2k - Cause change at the output of the bridge circuit. 3. Device according to claim 1, characterized in that g e k e η η, that the first and second control circuits are coupled to each other so that the through the solenoid (9) of the solenoid valve (8) flowing current according to the temperature decrease of the heated medium as a result of the interruption the gas combustion in the gas burner (2) slowly »uniraint, and that when the current reaches a predetermined level, the current can increase very quickly, and that the ignition of the gas burner (2) takes place before the rapid increase in current. k. Device according to claim I _9, characterized in that the first and second control circuits are coupled to one another in such a way that the current can slowly decrease in accordance with the temperature rise of the heated medium, and that the current can decrease very quickly if the current falls below the predetermined level. 5. Device according to claim 1, characterized in that the first control circuit for controlling of the excitation current comprises the bridge circuit and a first active element (56) through a second active, flic output circuit element representing the bridge circuit (55) is controlled, the output circuit of the first active element (56) in series with the solenoid (9) of the solenoid valve (ß) is switched, and that the second control circuit a Detector circuit to detect the solenoid (Q) fies 209884 / 10G9 - 25 - Solenoid valve (8) applied voltage and a third active element (63) corresponding to the detected Voltage is controlled, the output of the third active element (63) so connected to one arm of the bridge circuit is that the change in the output current of the output circuit is a change in that at the second active element of the bridge circuit applied bias. 6. Device according to claim i, characterized in that the proportional solenoid valve (9) has the solenoid (8), a plunger (lh) and Fe of the devices (17, 17a) for holding the plunger (lh) . 7. establishment; according to claim 6, characterized in that the spring devices are leaf springs (17, 17a), one side of which is firmly attached to a fixed part (11, Ha) of the device, while the the other side is fork-shaped, that the fork-shaped parts of the leaf springs laterally from the plunger (14) run away from the fixed side, and that the front ends of the fork-shaped parts of the leaf springs (17, 17a) protrude from the plunger core (14) Hold arm. 8. Device according to claim 6, characterized in that the spring devices are first leaf springs. (33) ■ have one side fixed to a stationary one Part (ii, lla) of the device is attached that each $ 209,884 / $ 106 - 26 - the other side of the leaf spring (33) is fork-shaped (33a, b), that the fork-shaped parts of the leaf springs run laterally on the plunger core (l'i) away from the fixed side, that second leaf springs (36) on the front Ends of the fork-shaped parts (33a, 33b) are attached and to the fixed side of the first leaf spring (33) to run cn, and that the front ends of the second leaf springs (36) hold the plunger (l'i). 9. Device according to claim 6, characterized in that the spring devices means (18, 19) to adjust their counter or restoring force. $ 209,884 / $ 106