KR100738013B1 - Electric current balancing device - Google Patents

Abstract

A current balancing apparatus is provided to control the stability of a load by comparing a current of each load with an adjusted reference current. A current balancing apparatus includes at least one load(4), a feedback circuit(1), a detecting circuit(2), and at least one balancing transformer(3). The feedback circuit(1) consists of a driving stage(11) and at least one output transformer, and provides a current to the load(4). The detecting circuit(2) is connected between an input stage of the feedback circuit(1) and a detecting point, receives and detects the current of the total load, collects the stably flown current in the input stage of the feedback circuit(1), and makes the feedback circuit(1) output a stable reference current. The balancing transformer(3) receives the stable reference current outputted from the feedback circuit(1) by a primary side coil, serially connects the load(4) with a secondary side coil, compares the current of each load(4) with the reference current outputted from the feedback circuit(1), controls the stability of the load, and balances the current.

Description

Electric current balancing device

1 is a basic structure of the current balancing device of the present invention and its application schematic

2 is a schematic diagram of a first embodiment of the present invention;

Figure 2a is a schematic diagram of a first embodiment and another embodiment of the present invention

2B is a schematic diagram of a first embodiment and another embodiment of the present invention;

Figure 2c is a schematic diagram of a first embodiment and another embodiment of the present invention

3 is a schematic view of a second embodiment of the present invention;

4 is a schematic view of a third embodiment of the present invention.

5 is a schematic view of a fourth embodiment of the present invention.

6 is a schematic view of a fifth embodiment of the present invention.

7 is a schematic view of a sixth exemplary embodiment of the present invention.

8 is a schematic view of a seventh embodiment of the present invention.

9 is a schematic view of an eighth embodiment of the present invention.

10 is a schematic view of a ninth embodiment of the present invention.

11 is a schematic view of a tenth embodiment of the present invention.

12 is a schematic view of an eleventh embodiment of the present invention.

12A is a schematic diagram of an embodiment of integrating a balanced transformer and a class inductor of the present invention.

** Explanation of symbols for main parts of drawings **

1: Feedback circuit 11: Drive end

12: switching stage 2: detection circuit

3: Balance transformer 4: Load

5: Classified inductor C: Ballast capacitor

T ： Output transformer

Taiwan Patent Publication No. 4478902 "Multi-pipe Driving System"

The present invention relates to a current balancer, in particular to comparing the current of the load with a stable (regulated) standard current using a balance transformer to control the stability of the load and to reach the function of current balancing.

In general, liquid crystal display (LCD) panels mostly provide sufficient brightness with several backlight discharge lamps. Therefore, in the provision of the above-described lamps, two or more parallel-connected lamps (such as a single transformer or other power conversion system) may be used. When driving a lamp or light tube, the impedance difference between each lamp will severely affect the even distribution of the lamp current in each parallel lamp, resulting in too little (or too large) current, resulting in lack of brightness (or Too bright), and also affect the light source uniformity of the liquid crystal monitor panel.

In addition, when the current is too high, the service life of the lamp itself and the entire system is shortened. Also, the component error of the feedback circuit and the lamp characteristic cannot be controlled precisely according to the situation such as the change of time. .

In severe cases, the lamp will have negative electrical resistance, and if the lamp current increases after the lamp is operated, the lamp voltage will also be relatively low, and other parallel output lamps will be fixed in an electrical position where the input voltage is already low and will not operate smoothly. This glittering phenomenon occurs.

In addition, Taiwan's patent publication No. 479592, "Multi-pipe drive system," is an output load of a single feedback circuit, which uses an impedance matching principle to control lamp current. Equilibrium has been reached. The above-mentioned system is based on the main (first) lamp in operation, and then the other sub-lamp (the second lamp) in order to combine with the main lamp The impedance of the current is balanced, and there is a slight error between each lamp that is still not calculated during manufacturing.

For example, as the length and diameter of the lamp, the density of mercury, the pressure, the electrode coating layer, etc. vary, the lamp voltage creates an offset of the internal impedance characteristic curve of the lamp current so that each lamp is in the best working condition. It is not maintained and also does not reach the effect of the equilibrium current.

Therefore, the present invention is directed to improving the above-mentioned shortcomings and simultaneously using a balance transformer to control the stability of the load by comparing the current of each load with a stable (adjusted) standard current and reaching the effect of current balancing. This is a technical difficulty to solve.

The main object of the present invention is to provide a current balancing device, at least one load (lamp or light tube (for example CCFT (cold cathode fluorescent lamp)), light emitting components (for example LED or Applied to control circuits with OLED), single-phase or multi-phase voltage regulator modules (e.g. Multi-phase DC-DC Converters), which include, but are not limited to, feedback circuits: ) Is used to allow current to be provided to the load, and a detecting circuit is used to receive and detect the amount of current of the total load (or the specified load) of the control circuit, and also to make the current amount stable. After flow (rectification filtration), it is returned to the input of the feedback circuit and used to cause the feedback circuit to output a stable (regulated) standard current. At least one balancing transformer is used for the primary side nose. The work receives the stable (adjusted) standard current, the secondary side coil individually connects the load in series, and in this way (Lenz's Law states that the direction of the sensitive When a change occurs in the current on the secondary side of the balance transformer (i.e. when a change occurs in the load current), the secondary side (individual load) and the stable (adjusted) on the primary side The standard currents are compared with each other to control the stability of the load and to reach the effect of current balance.

Hereinafter, other features, advantages, and possible effects of the present invention will be described with reference to the drawings.

Referring to Figure 1, the present invention provides a current balancing device, at least one load 4 (lamp (light or light tube) (for example CCFT (cold cathode fluorescent lamp)), light emitting components (for example For example, it applies to control circuits with LEDs or OLEDs, single-phase or multi-phase voltage regulator modules (e.g. Multi-phase DC-DC Converters), including the following: (1) consists of a driving unit (11) and one or more output transformers (T), used to provide current to the load (4), and a detecting circuit (2) Connected between an input terminal of the feedback circuit 1 and a current recovery detecting point of the load (e.g., the low voltage side of the load 4) so that the total load (or specified) of the control circuit It is used to receive and detect the amount of current in the load) (4), and the amount of current is stable. After flow, it is recovered to the input of the feedback circuit 1 and is used to cause the feedback circuit 1 to output a stable (adjusted) standard current, and at least one balance transformer 3 has a primary side coil A stable (adjusted) standard current output from this feedback circuit 1 is received, the secondary side coils individually connect the load 4 in series, and again in the above-described structure, the law of Lenz ( The back emf principle of operation between the primary side coil and the secondary side coil of the balanced transformer 3 of the present invention according to Lenz's Law is as follows.

among them,

E: electric field strength, D: electric flux strength (intensity), J: electric current density, H: magnetic field strength, B: magnetic flux strength (intensity), φ: magnetic flux in iron core (magnetic flux in the ferrite core), μ: magnetic permeability L: inductance

By the law of Maxwell-Faraday's Law and Maxwell-Ampere's Law,

이므로 방향량 적분을 거치고 다시 스톡스의 정리(Stoke's Theorem)을 인용하면, 면적분이 선적분으로 전환한다. 즉,A stationary closed path C

Therefore, after directional integration and requoting Stokes' Theorem, the area is converted to the shipment. In other words,

The present invention obtains the following relationship.

In addition, the present invention uses a coaxial soft magnet as a core in the design of a balanced transformer, and further, obtains an electro-motive force (emf) on the coil and a magneto-motive force (mmf) in the core. Each of them looks like this:

therefore,

It can be seen that the response voltage appearing at both ends of the secondary coil after the simple formula described above represents the counter electromotive force, and the magnitude thereof should be as follows.

At the same time also the primary side current i _p of the present invention is already standardly stable current and also d (n _p i _p ) / dt = 0, thus further obtaining below.

In this way, one of the above-described relations

When an unbalanced current occurs between the primary side and the secondary side of the balance transformer 3, its counter electromotive force Vs is the change in current of the secondary side ( That is directly proportional to di _s / dt and at the same time the inductance Ls of the secondary side rises and increases, i.e. this back electromotive force Vs increases the inductance Ls of the secondary side. The secondary side coil of the balance transformer 3 effectively suppresses the current of the load 4 connected in series so that the secondary side current of the balance transformer 3 is increased. Under counter electromotive force, a mechanism is achieved that is completely balanced (matched) with the current on the primary side (i.e., the primary and secondary sides are opposite, so that the gaps generated by the individual currents disappear from each other, The iron core of this balanced transformer maintains the non-saturation zone, improves inductance, and simultaneously The current counter electromotive force caused by the change in the number of times the other hand effectively stabilize the load).

Thus, as illustrated in FIG. 1, according to the embodiment of the present invention, when the control circuit of the current balancer of the present invention is operated, the current amount of the total load 4 in the control circuit through this detection circuit 2 ( io) is received and detected, and the current amount is flowed stably and then recovered to the input terminal of the feedback circuit 1 so that the output of the feedback circuit 1 is a stable (adjusted) standard current. The balance transformer (3) leads to the load (4).

In this way (under the application of Lenz's law), when the balance transformer 3 changes in the current on its secondary side (i.e. when a change occurs in the current on the load 4), the secondary of this balance transformer 3 The side (i.e. load 4) generates back electromotive force and compares (matches) with the stable (adjusted) standard current on the primary side to control the stability of this load 4 and reach the effect of current balance. do.

At the same time, the counter electromotive force characteristic of this balanced transformer 3 further increases the voltage of the undriven (lighted) load 4 to the driving (lighted) state, thereby effectively controlling each load 4 to drive (lighting). ) To the state.

In summary, as illustrated in FIGS. 2 to 12, this shows a schematic diagram of various embodiments of the present invention in which the current balancer of the present invention is variously applied.

This balance transformer (3) is represented by (CB), the primary side coil is represented by (n1), the secondary side coil is represented by (n2), and other conventional The balance transformers used between the loads are denoted by (BT), and the ballast capacitors applied in FIGS. 2 to 10 are denoted by (C).

Therefore, the balanced transformers 3 of FIGS. 2, 3, and 4 are provided on the secondary side of the output transformer T of the feedback circuit 1, and the high-pressure side of the load 4 in a mutual or parallel manner (FIG. 2). (3), the low voltage side (Fig. 4) is individually connected in parallel and the stable (adjusted) standard current output from this feedback circuit (1) is separately sent to the load (4) for comparison. Stability and current balancing effect.

In addition, C in Figs. 2 and 3 is a ballast capacitor for voltage distribution of a lamp or light tube series connection when adopting an indirect drive method, for example, when employing a direct drive method. This ballast capacitor C is relatively eliminated and not used. 2 and 3 have exactly the same circuit structure.

In addition, the example illustrated in FIG. 2A improves the working voltage by connecting two output transformers T in series when a large and long lamp (high voltage load) is used. In order to prevent arcing phenomena from occurring, the lamps are floated at this time, the two output transformers (T) series connection is grounded, and the flow-connected lamp is grounded virtually in the middle so that the voltage of the lamps is reduced. It is relatively reduced in half, thereby reaching the effect of stability and current balance of each load 4.

On the other hand, the example illustrated in FIG. 2B or 2C also applies to the load 4 by using two lamps or several lamp package sets, using the same package in common with the balance transformer 3. Combined into a single package, it becomes a twin or triplet structure or the like, so that the load currents of the individual lamps in the same lamp set are matched, thereby allowing each load 4 The effect of stability and current balance is reached. That is, the balance transformer includes at least two coils on the secondary side to be assembled into one twin or several twin structures.

5, the balance transformer 3 is installed between the primary side of the output transformer T of the feedback circuit 1 and the driving stage 11, and the output transformer T is driven in parallel with each other. By connecting the driving units 11 in parallel, the stable (adjusted) standard currents output from the driving stage 11 are separately sent to the load 4 via the output transformer T for comparison. The effect of stability and current balance on each load 4 is reached.

6, the balance transformer 3 is installed between the primary side of the output transformer T of the feedback circuit 1 and the driving stage 11, and has a tree-shaped regular incremental array method. The output transformer T and the driving stage 11 are relatively connected in parallel, so that the stable (adjusted) standard current output by the driving stage 11 is separately divided into the load 4 via the transformer T. By comparison, this results in the stability of each load 4 and the effect of current balance.

7, 8, this balance transformer 3 is installed between the primary side of the output transformer T of the feedback circuit 1 and the drive stage 11, and the output transformer T and the drive are mutually parallel. Connected in series to the stage 11 individually, and at the same time, the secondary side of the output transformer T is replaced with a general equilibrium transformer BT, so that the high pressure side of the load 4 of each set (FIG. 7), The low voltage side (Fig. 8) is connected in series, and the stable (adjusted) standard current output from the drive stage 11 is separately sent to the load 4 via the transformer T for comparison. Stability and current balancing effect.

9 and 10, the balance transformer 3 is installed between the primary side of the output transformer T of the feedback circuit 1 and the driving stage 11, and the output transformer T and the drive are mutually parallel. In series with a transformer (T) having two output stages separately at the stage (11), and at the same time, the common balance transformer (BT) is connected to the high pressure side (Fig. 9), the low pressure side ( 10), the stable (adjusted) standard current output from the drive stage 11 is separately sent to the load 4 via the transformer T, and compared, thereby ensuring the stability of each load 4 The effect of overcurrent balance is reached.

In Fig. 11, this load 4 is further applied in combination with other light emitting components (e.g., LEDs or OLEDs), which is a state diagram of the control circuit applied, which is also the same as in Figs. Therefore, the present invention will be described only as one embodiment.

Among them, the balanced transformer 3 is installed on the secondary side of the output transformer T of the feedback circuit 1, and is individually connected in series to the low pressure side of the load 4 in parallel with each other (also connected in series to the high voltage side). ), The stable (adjusted) standard current output by the feedback circuit (1) is separately sent to the load (4) for comparison, thereby reaching the stability of each load (4) and the effect of current balance, thereby different colors By adjusting the number of coils between the primary side and the secondary side of the balanced transformer (3) connected in series with the light emitting components of the To keep.

In FIG. 12, the present invention further applies the balancing transformer 3 to a control circuit such as single phase or multi phase voltage regulator modules (VRMs-Voltage Regulator Modules). .

Among them, the balance transformer 3 is provided between a switching unit 12 included in the feedback circuit 1 and a distributing inductor 5 outside thereof (internal connection), This distributes the current equally across each class of inductor to control the uniform distribution of heat sources across the entire module.

Further, in this embodiment, the structural design of the iron core and the coil further proceeds to integrally assemble the balanced transformer and the class inductor of this circuit (FIG. 12A), and the differential mode coupling effect between the primary side and the secondary side. The coupling effect is applied to the balance transformer using Lc), and the same effect of the uniform classification is achieved by using the magnetic leakage inductance (Lk) of the connection part as the classification inductor.

Thus, the technical feature of the present invention is to achieve the stability of the load 4 and the function of current balancing by comparing the current of each load 4 with the stable (regulated) standard current, respectively, using the balance transformer 3. At the same time, it effectively controls the driving (lighting) state of each load 4.

In order to show the progress and practicality of the present invention, a comparative analysis is as follows.

`` Characteristics of Conventional Technology ''

1. Pre-installed based on the main lamp, and then balanced the resistance of the current by combining the other sublamps with the main lamp in order.

2. Due to the difference of each lamp situation, slight error effect may occur.

3. The lamp voltage creates an offset of the internal impedance characteristic curve of the lamp current.

This causes each lamp to remain in its proper state and does not reach the function of balanced current.

5. When several lamps are applied in parallel, the initial lamp is activated to suppress the operation of other lamps, which makes it inappropriate for use in direct drive design mode.

`` Advantage of the present invention ''

1. Use a balance transformer to compare the current of each load with one stable (regulated) standard current.

2. Exclude the influence of minute error caused by the situation of each lamp.

3. Effectively control the stability of the load and reach the function of current balancing.

4. Effectively control the driving (lighting) status of each load.

5. It can be used in various direct drive design modes by overcoming the position of the lamp to operate for the first time due to the back EMF effect, improving the efficiency of the whole module.

In summary, the present invention has revolutionized the prior art structure and clearly reached the effect of improvement, and it is easily conceived even by an unskilled person in this field. This application is submitted because it is practical and meets the requirements of the invention.

It is noted that the foregoing is only a relatively specific embodiment of the present invention, and that any changes made to the above-described methods, shapes, structures, and apparatuses fall within the scope of the present invention.

Claims (7)

At least one load; A feedback circuit comprising a drive stage and at least one output transformer, the feedback circuit providing current to the load; It is connected between the input terminal of the feedback circuit and the current recovery detecting point to receive and detect the current amount of the total load, and after the current flows stably, the feedback circuit recovers to the input end of the feedback circuit to provide a stable standard current. Output detection circuit; And The primary coil receives the stable standard current output from the feedback circuit, and the secondary coil individually connects the load in series, comparing the current of each load with the standard current output from the feedback circuit, respectively, to ensure the stability of the load. And at least one balance transformer for controlling and balancing the current. The current balancer of claim 1, wherein the balance transformer is installed between the primary side of the output transformer of the feedback circuit and the driving stage. The current balancer of claim 1 or 2, wherein the balance transformer includes at least two coils on the secondary side to be assembled into one twin or multiple twin structures. 3. The current balancing device according to claim 1 or 2, wherein the load is at least one lamp or light emitting component. 4. The current balancing device of claim 3, wherein the load is at least one lamp or light emitting component. 3. The current balancing device according to claim 1 or 2, wherein the load is a single phase or polyphase voltage regulating module (VRM). 4. The current balancing device of claim 3, wherein the load is a single phase or polyphase voltage regulation module (VRM).

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