ELECTRIC POWER SAVER BY TROIDAL CORE Technical Field The present invention relates to a power saver employing a toroidal core that is provided to step down a high supply voltage of a tap near a distribution transformer, which will be supplied to consumers, and then to apply the stepped down voltage to a load without transformation loss ; wherein a core is subjected to heat treatment several times to form the toroidal core in a roll form so as not to have a core gap, for the purpose of saving power and protecting electric equipment; also wherein a primary coil and a secondary coil are wound on the toroidal core along an external surface thereof in a single-row winding fashion so that the primary and secondary coils overlap each other with almost the same winding angle coverage, whereby a magnetic flux of the primary coil is transferred to the secondary coil without causing a loss of the flux linkage, thereby minimizing the core loss ; and further wherein a harmonic filter including a series coil L2 and a harmonic capacitor C2 filters out harmonics occurring while the power is supplied, and a power factor compensator including a compensation capacitor Cl and the harmonic capacitor C2 performs power factor compensation at the same time, thereby removing invalid currents and supplying high-quality power to the load, thus saving power.

Background Art Generally, conventional cores used for step down transformers have been made by assembling EI cores. Accordingly, a very high power loss occurs in the cores when stepping down the voltage since there are close gaps in the cores. In addition, since the conventional cores have high volume and weight, they are difficult to carry and also very troublesome to install.

A conventional step down transformer employing a toroidal core uses a zigzag winding scheme, as shown in Fig. 2a, in which a primary coil is wound on the core from its beginning to end and then wound on the core backward, from its end to beginning. The conventional step down transformer has a very high voltage difference between coils due to the zigzag winding scheme and thus has a low thermal resistance, which causes them to be short-circuited, thereby shortening

the transformer's life.

Disclosure of the Invention Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a power saver employing a toroidal core that employs a new method for winding coils on a toroidal core, whereby the coils are prevented from being short-circuited due to the high voltage difference, and there is almost no loss in magnetic flux linkage of a toroidal primary coil LI, which is induced by an exciting current of a toroidal secondary coil L3, thus allowing a power saver circuit to be made with almost no internal power loss.

It is another object of the present invention is to provide a power saver employing a toroidal core, which achieves power transformation without causing a loss thereof, and reduces unnecessary power consumption, and further improves power quality.

In accordance with the present invention, the above and other objects can be accomplished by the provision of a power saver employing a toroidal core, comprising: a step down transformer including a toroidal primary coil, a bypass switch and a toroidal secondary coil connected in parallel, said step down transformer stepping down a voltage applied to the primary coil and applying the stepped down voltage to the secondary coil ; a harmonic filter including a series coil and a harmonic capacitor, said filter filtering out harmonics of an electrical signal received from the step down transformer ; a power factor compensator including a compensator capacitor and the harmonic capacitor, said compensator compensating for a power factor of an electrical signal of the harmonic filter; and a detector for detecting a current and voltage of the power saver's circuit.

Brief Description of the Drawings The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a circuit diagram showing a power saver employing a toroidal core to which a technology of the present invention is applied ; and

Fig. 2a shows a method for winding coils on a toroidal core in the prior art ; and Fig. 2b shows a method for winding coils on a toroidal core employed in a power saver according to the present invention.

Best Mode for Carrying Out the Invention Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings.

Fig. 1 is a circuit diagram showing a power saver employing a toroidal core to which a technology of the present invention is applied. The configuration and operation of the present invention will now be described in detail with reference to this figure.

As shown in Fig. 1, the power saver circuit includes a step down transformer 10, a harmonic filter 20, a power factor compensator 30, and a current and voltage detector 40. The step down transformer 10 includes a toroidal primary coil (LI) 11, a bypass switch (S/W) 13, and a toroidal secondary coil (L3) 12 connected in parallel. The step down transformer 10 steps down a voltage applied to the primary coil (LI) 11 and applies the stepped down voltage to the secondary coil (L3) 12. The harmonic filter 20 includes a series coil L2 and a harmonic capacitor C2 to filter out harmonics of an electrical signal received from the step down transformer 10. The power factor compensator 30 includes a compensator capacitor Cl and a harmonic capacitor C2 to compensate for a power factor of an electrical signal of the harmonic filter 20. The detector 40 detects a current and a voltage of the toroidal power saver circuit.

The step down transformer 10 allows a voltage inputted through a non-fuse breaker NFB1 to be stepped down through switching contacts of the bypass switch (S/W) 13 and the primary coil (L 1) 11 and then to be applied to the secondary coil (L3) 12. An exciting current induced in the secondary coil (L3) 12 is provided to the primary coil (L1) 11 without current loss.

Accordingly, the stepped down voltage and an increased current, from the electricity in the secondary coil (L3) 12, the bypass switch (S/W) 13 and the primary coil (L1) 11, are supplied to a load through the series coil L2.

The harmonic filter 20 includes the series coil L2 and the harmonic capacitor C2 connected in parallel so as to selectively reduce specific harmonics.

The power factor compensator 30 includes the compensator capacitor Cl and the harmonic capacitor C2 connected in parallel so as to compensate for a low power factor. The detector 40 detects the voltage and current of a load through a current transformer CT. The detected voltage and current value is calculated by a microcomputer CPU of a PCB controller 41, and the calculated value is displayed on an LCD-FND 42.

If the input voltage of the non-fuse breaker NFB1 is reduced below a reference value, a semiconductor switch SSR and the bypass switch S/W are operated, so that the exciting current of the toroidal secondary coil (L3) 12 is cut to protect electric equipment on the load side, and the toroidal primary coil (LI) 11 is short-circuited. This causes the input voltage to be bypassed to the output side, so as to perform harmonic reduction and power factor compensation.

The conventional toroidal core usually employs the zigzag winding scheme as shown in Fig. 2a. However, the present invention employs a single-row winding scheme, as shown in Fig. 2b, in which the coils are wound in a single-row fashion with almost the same winding angle coverage so that a magnetic flux of the secondary coil (L3) 12, induced by the exciting current, is linked so as to waste no magnetic flux. In addition, the single-row winding scheme according to the present invention maximizes the power transformation efficiency of the toroidal primary coil (L1) 11 and the toroidal secondary coil (L3) 12, while minimizing the internal power loss.

Regarding the same winding mounting angle, the primary coil (L1) 11 and the secondary coil (L3) 12 are coincident with respect to a single axis, and a portion (b) of the primary coil (LI) 11, as an exciting-current coil, is wound near a portion (f) of the secondary coil (L3) 12. Since the coil is wound in such a manner that the current flow thereof is very close to the linked primary coil (LI) 11, the efficiency is greatly improved. In addition, since the present invention does not employ the conventional zigzag winding method for winding the exciting coil consisting of 1300 turns or more, the voltage difference between the coils is low, thereby preventing the coils from being short-circuited due to deterioration.

If the power supply voltage inputted though the non-fuse breaker NFB1 is lower than a reference value, a relay coil SW for turning on and off the exciting current is operated so that the bypass switch S/W is closed to bypass the input voltage.

Accordingly, the power is subjected to the harmonic reduction and power

factor compensation, before being supplied to the load, so that continuous high- quality power (efficiency of 99.4% : refer to a test value in Korea Electrotechnology Research Institute) can be supplied to the load, thus saving power.

Industrial Applicability Since the conventional step down and step up transformers commonly use EI cores, they have problems in that there is a high no-load loss in the cores, and they also have a high volume and weight, compared to their capacity, so that they are very troublesome to carry. In addition, since the conventional toroidal core employs a zigzag winding scheme, the voltage difference between the coil turns (or coil layers) is very high, an excessive voltage or an instantaneous peak current frequently causes them to be short-circuited.

However, the present invention provides a power saver employing a toroidal core, which comprises a step down transformer including a toroidal primary coil, a bypass switch and a toroidal secondary coil connected in parallel, said step down transformer stepping down a voltage applied to the primary coil and applying the stepped down voltage to the secondary coil; a harmonic filter including a series coil and a harmonic capacitor, said filter filtering out harmonics of an electrical signal received from the step down transformer; a power factor compensator including a compensator capacitor and the harmonic capacitor, said compensator compensating for a power factor of an electrical signal of the harmonic filter; and a detector for detecting a current and voltage of the power saver's circuit.

In addition, the current and voltage are detected, and a value thereof is calculated by a microcomputer (CPU) of a PCB controller, and the calculated value is then displayed on an LCD-FND display. Further, the coils of the toroidal core are wound in a single-row winding fashion, in which the primary and secondary coils overlap each other with almost the same winding angle coverage. Thus, power to be supplied to the consumer can be effectively transformed without causing an internal power loss of the equipment. Moreover, thanks to power factor improvement and harmonic reduction, high-quality power can be supplied to the load, thereby greatly saving power.

In particular, it is considered that the introduction of a power saver according to the present invention into various electric home appliances will be a basis for saving power. Further, the power saver according to the present invention

is expected to dominate the domestic market and further achieve competitiveness in the global market, which will have considerable ripple effects in various fields and also greatly contribute to the acquisition of foreign currencies.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.