|Title of Invention
|The invention refers ot electric equipment, in particular to the filters for attenuation and exclusion of high-frequency electromagnetic components in the power alternating current networks. The technical result to be achieved upon the use of the invention is significant decrease in the amplitude of high-frequency electromagnetic component of the voltage in the frequency range of 1-100 kHz, as well as simplification and reduction of filter dimensions. The specified technical result is achieved in the supply-line filter containing condenser and resistor in which non-inductive thin-film condenser is used to which resistor is connected in parallel. Condenser with capacity of 5- 30 μF and resistor with resistance of 20-100 kΩ is used mainly in the filter.
THE PATENT ACT 1970
(39 of 1970)
The Patents Rules, 2003 COMPLETE SPECIFICATION (See section 10 and rule 13)
1. SUPPLY-LINE FILTER
(C) 520 West Broadway Str., Blair, WI 54616,USA
The following specification particularly describes the invention and the manner in which it is to be performed.
The invention refers to electric equipment, in particular to the filters for suppression or elimination of high-frequency electromagnetic components in the circuits of alternate power current.
Supply-line interference suppressing filters are known on discrete elements which include condenser and coil /Technical Conditions MRTU 45- 1110-67(Russia)/. Since these filters are designated to suppression of interference in the feeding circuits with the voltage of up to several hundreds if volts with currents of up to several amperes, condensers and coils of such filters have large dimensions, weight and price. The rated capacity of condensers used in these filters amounts to 0.5-1.0 uF, which leads to large currents of filter leak and increases significantly the starting current upon supply of the voltage of the feeding network to the filter. Besides, these filters provide mainly attenuation of disturbances with the frequency of over 1MHz, while the efficiency of filter is insignificant on the lower frequency ranges within the limits of 1-100 kHz.
Filters are known in which the coil and condenser are combined constructively and electrically since the coil is made of metal band which is one of the condenser facing at the same time. For example, filter of disturbance suppression / US Patent 4563658, Int. CI. H 03 H 7/01, 1986/ consists from two metal bands and alternate dielectric spacers being put one over another and rolled up. One metal band is provided with electric outputs at the both ends; it plays the role of the coil and serves as one of condenser facing at the same time. The second band serves as another facing which acts as ferromagnetic core for the first band increasing in inductance. The rated capacity of condenser of this filter is equal to 0,01 uF. Such constructive design of the filter significantly decrease the weight and dimensions of the filter upon the high efficiency of its operation at high and
very high frequency, however the filter is not so efficient on the lower frequency ranges.
Filter / Certificate of Authorship 1488918 (USSR), Int. CI. H 02 J 3/01, 1/02, 1989/ is the prototype of invention which contains reactor (coil), condenser and resistor the first outputs of which are connected into star and the second outputs of condenser and reactor are connected to the circuit and transformer which intermediate output is connected to the clamp of the network connected with reactor. Availability of transformer in the structure of the filter reduces power losses, however it increases the dimensions of the filter and its weight. Similar to previously considered analogues, this structure is not efficient enough upon filtration in the frequency modes of 1-100 kHz.
The task for solution of which the applied invention is designated, is formation of a device allowing elimination of high-frequency electromagnetic component of the voltage in alternate power current networks relating to the range of 1-100 kHz. Known filters eliminate mainly high-frequency component of power having the frequency of more than 1 MHz and introducing disturbances which complicate the operation of switched on equipment such as radio and TV devices, computers, however, they do not much influence the low-frequency range of disturbances. At the same time exactly the low frequency range of electromagnetic oscillations possessing lower capacity to weakening depending on the distance from the source of oscillations, more negatively affects the human organism, and elimination of such electromagnetic pollution assists to the formation of favorable environment for human life.
The technical result being achieved upon the use of the invention, is significant decrease in the amplitude of high-frequency electromagnetic component of the voltage in the frequency mode of 1-100 kHz, as well as simplification and reduction of the filter dimensions.
The specified technical result should be achieved in the supply-line filter containing condenser and resistor in which non-inductive thin-film condenser is
used, to which resistor is connected in parallel. Condenser with capacity of 5-30 uF and resistor with resistance of 20-100 k, are used mainly in the filter.
The use of non-inductive thin-film condenser in the filter eliminates the chance of occurrence of resonance in the circuit, which may lead to distortion of the form of utility signal. Besides, such condenser are characterized with stable characteristics, durability and small dimensions which increases the reliability of filer operation. The description of such condensers is given in /Standart Handbook for Electrical Engineers. /Donald G. Fink, H. Wayne Peaty -: McGraw-Hill, 14 edition., 1999, 2200 p./. Such condensers were previously used, for example, in operational amplifiers /Integrated circuits and their foreign analogues: Reference book. Volume 2 / A.V.Nefedov - M.: IP RadioSoft, 1999, 640 p./, however, there are no data of their use in the supply-line filters.
The shunting resistor is connected in parallel to condenser which serves more intensive attenuation of low-frequency oscillations in the circuit, since the resistor together with condenser form oscillating RC-circuit having small Q-factor, i.e. possessing the ability to absorb oscillations rather quickly. The use of condenser with capacity of 5-30 of and resistor with resistance of 20-100, as it was determined by tests, allows more efficient elimination of electromagnetic oscillations with the frequency of 1-100 kHz in the alternating current network.
The diagram of filter is given in fig. 1.
The filters includes condenser 1 and resistor 2 connected in parallel as well as outputs 3 designated to incorporation into the alternating current network. The filter is constructively made in the form of cavity case inside of which condenser and resistor are located, equipped with outputs for connection to the alternating current network.
High-frequency electromagnetic component of the voltage is applied on the main signal in the alternating current networks with the voltage of 127-220 V and frequency of 50-60 Hz. It is generated by such electric equipment as personal computers, copying machines, printers, facsimile machines, radio and TV devices.
Such high-frequency component is the source of electromagnetic oscillations which, along with formation of disturbances for equipment operation, lead for formation of electromagnetic field which negatively affects the human organism. Electromagnetic oscillations in the ultrahigh frequency range (over 1 MHz) attenuate faster with the distance, therefore oscillations in the range of 1-100 KHz are more hazardous for the human, since they are less weakened upon the increase of the distance from the source of oscillations.
Upon connection of filter to the network which consists from condenser 1 and resistor 2 connected in parallel, the voltage of the reference frequency and high-frequency component of the voltage are supplied t the facing of condenser 1. The resistance of condenser varies for he signals having different frequency and it may be represented as follows:
R = l/(2*f*C),
where f and C - signal frequency and condenser capacity, accordingly.
The filter resistance is rather significant for the main network power (127-220 V, 50-60 Hz), and resistance is small for the high-frequency electromagnetic component which results into the nearly short circuit of the high-frequency component on condenser and its elimination from the alternating current network. Resistor 2 forms together with condenser 1 the oscillating RC-circuit the duration of transition process of oscillation attenuation in which depends on the value of resistance of resistor 2. It was determined by the tests that it is expedient to use condenser with capacity of 5-30 F and resistor with resistance of 20-100 k for the most efficient elimination of high-frequency component of the voltage in the interval of 1-100 KHz from the alternating current.
Data on the amplitude and frequency of the high-frequency component in the alternating current network with the voltage of 220 V and frequency of 50 Hz are given as an example without use. of the filter and with its connection to the network (the filter included non-inductive thin-film condenser with capacity of lOuF and resistor with resistance of 50 k).
Table. Results of filter usage in alternate current network
Signal frequency, kHz Signal amplitude without filter usage, V Signal amplitude upon filter usage, V
0,9 3,0 1,0
1,2 3,0 1,0
1,4 3,7 1,3
1,8 2,4 1,0
2,2 2,0 0,4
2,9 3,5 1,1
3,1 2,2 1,2
3,6 2,9 1,8
4,2 2,8 1,3
4,5 2,8 1,0
5,5 5,8 1,5
7 5,8 0,2
10 5,8 0,0
12,5 5,0 0,0
16,7 6,7 0,0
25 6,3 0,0
50 3.2 0,0
100 3.0 0,0
The results of measurements evidence that attenuation of high-frequency electromagnetic components occurs in the frequency range of 1-5 kHz by 30-50%, and for the frequencies higher than 7 kHz, nearly complete attenuation of high-frequency electromagnetic components of the voltage.
1. Supply- line filter including condenser and resistor characterized
in that it includes non-inductive thin-film condenser which is connected to the resistor in parallel.
2. Supply-line filter according to claim 1, wherein said condenser
has a capacity of 5 - 30 F and resistance of the resistor amounts to 20-100 K
Dated this on 17th day of December, 2005.
The invention refers to' electric equipment, in particular to the filters for attenuation and exclusion of high-frequency electromagnetic components in the power alternating current networks.
The technical result to be achieved upon the use of the. invention is significant decrease in the amplitude of high-frequency electromagnetic component of the voltage in the frequency range of 1-100 kHz, as well as simplification and reduction of filter dimensions.
The specified technical result is achieved in the supply-line filter containing condenser and resistor in which non-inductive thin-film condenser is used to which registor is connected in parallel. Condenser with capacity of 5-30 F and resistor with resistance of 20-100 k is used mainly in the filter.
|Indian Patent Application Number
|PG Journal Number
|Date of Filing
|Name of Patentee
|STETZER David A.
|520 West Broadway Str., Blair, W1 54616,
|PCT International Classification Number
|PCT International Application Number
|PCT International Filing date