CN202586883U

CN202586883U - Capacitance-resistance filter

Info

Publication number: CN202586883U
Application number: CN 201220227345
Authority: CN
Inventors: 王文银; 沈筠; 王煜超
Original assignee: ZHENGWEI TECHNOLOGY (SHENZHEN) Co Ltd
Current assignee: ZHENGWEI TECHNOLOGY (SHENZHEN) Co Ltd
Priority date: 2012-05-21
Filing date: 2012-05-21
Publication date: 2012-12-05
Anticipated expiration: 2022-05-21

Abstract

The utility model discloses a capacitance-resistance filter which comprises a resistor (R1), a first capacitor (C1), a second capacitor (C2) and a third capacitor (C3), wherein the resistor (R1) is a cut-off frequency resistor; the first capacitor (C1) and the second capacitor (C2) are differential mode capacitors; the third capacitor (C3) is a common-mode capacitor; the resistor (R1) is connected in parallel to two ends of the third capacitor (C3); and the first capacitor (C1) is connected in series with the second capacitor (C2) and then is respectively connected in parallel with the resistor (R1) and the third capacitor (C3). The capacitance-resistance filter disclosed by the utility model has the advantages of simple structure, favorable filtering effect and lower cost.

Description

A kind of capacitance-resistance filter

Technical field

The utility model relates to microelectronic component, in particular a kind of capacitance-resistance filter.

Background technology

Filter (filter) is a kind of device that is used for eliminating jamming incoherent signal, obtains pure direct current with inputing or outputing through filtration.To the circuit that the frequency or the frequency beyond this frequency of CF are carried out effective filtering, be exactly filter, its function obtains a CF exactly or eliminates a CF.

In the prior art, filter is to be made up of a capacitor and an inductor, is called the filtering of L type, because filter uses inductor, structure is complicated, and cost is higher.

The utility model content

The utility model technical problem to be solved is: a kind of simple in structure, good wave filtering effect, lower-cost capacitance-resistance filter are provided.

The technical scheme of the utility model is following: a kind of capacitance-resistance filter comprises resistance R 1, first capacitor C 1, second capacitor C 2, the 3rd capacitor C 3; Said resistance R 1 is a cut-off frequency resistance, and said first capacitor C 1 and second capacitor C 2 are differential mode capacitor, and said the 3rd capacitor C 3 is a common mode capacitance; Said resistance R 1 is parallel to the two ends of said the 3rd capacitor C 3; Said first capacitor C 1 is with after second capacitor C 2 is connected, and parallelly connected with said resistance R 1, said the 3rd capacitor C 3 respectively.

Be applied to technique scheme, in the described capacitance-resistance filter, said first capacitor C 1 and second capacitor C 2 are Y2 safety electric capacity, and said the 3rd capacitor C 3 is an X2 safety electric capacity.

Be applied to each technique scheme, in the described capacitance-resistance filter, the resistance of said resistance R 1 is 1 megaohm, and the appearance value of said first capacitor C 1 and second capacitor C 2 is 15000pF, and the appearance value of said the 3rd capacitor C 3 is 0.1uF.

Adopt such scheme; The utility model is through being provided with resistance R 1, first capacitor C 1, second capacitor C 2, the 3rd capacitor C 3; Said resistance R 1 is a cut-off frequency resistance, said first capacitor C 1 and second capacitor C, 2 differential mode capacitors, and said the 3rd capacitor C 3 is a common mode capacitance; Thereby through pure capacitance resistance component is set, reaches and eliminate the good filter effect that disturbs, and owing to omitted the inductance in the existing filter, simple in structure, cost reduces.

Description of drawings

Fig. 1 is the circuit diagram of the utility model specific embodiment.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment, the utility model is elaborated.

As shown in Figure 1, present embodiment provides a kind of capacitance-resistance filter, and said capacitance-resistance filter only is provided with electric capacity and resistance, has simple in structure, good wave filtering effect, and cost is lower.

Wherein, said capacitance-resistance filter is provided with resistance R 1, first capacitor C 1, second capacitor C 2 and the 3rd capacitor C 3; And each connectivity port of said capacitance-resistance filter also is connected with live wire L, zero line N and the bottom line G of outside.

And said resistance R 1 is a cut-off frequency resistance, said first capacitor C 1 and second capacitor C, 2 differential mode capacitors, and said the 3rd capacitor C 3 is a common mode capacitance.

For example, resistance that can said cut-off frequency resistance R 1 is set to 1 megaohm, and the appearance value of said first capacitor C 1 and second capacitor C 2 is set to 15000pF; The appearance value that is provided with of said the 3rd capacitor C 3 is 0.1uF; According to formula F=1/ (2*3.14*R*C), the cut-off frequency that can calculate said capacitance-resistance filter is 1.5HZ, wherein; R is the resistance of cut-off frequency resistance R 1, and C is total appearance value of capacitance-resistance filter.

And said resistance R 1 is parallel to the two ends of said the 3rd capacitor C 3; Said first capacitor C 1 is with after second capacitor C 2 is connected, and parallelly connected with said resistance R 1, said the 3rd capacitor C 3 respectively.

Perhaps, said first capacitor C 1 and second capacitor C 2 are Y2 safety electric capacity, and said the 3rd capacitor C 3 is an X2 safety electric capacity.Safety electric capacity can not cause electric shock after generally being applied to the capacitor inefficacy, does not jeopardize personal safety, and it has comprised X electric capacity and Y electric capacity.X electric capacity is the electric capacity that is connected across between power line two live wire L and the zero line N, generally selects metallic film electric capacity for use; Y electric capacity is the electric capacity that is connected across respectively between power line two lines and the ground, i.e. electric capacity between live wire L and ground wire G and zero line N and the ground wire G, and Y electric capacity generally is paired appearance.

Wherein, Said first capacitor C 1 and second capacitor C 2 are Y2 safety resistance; Y2 safety electric capacity high pressure resistant greater than 5 kV is when crest voltage occurs, if during the differential mode capacitor poor-performing then might be breakdown; Though its puncture does not jeopardize life safety, can make the function reduction or the forfeiture of filter; Therefore it is breakdown to use Y2 safety electric capacity to prevent, anti-puncture is effective.

And said the 3rd capacitor C 3 is an X2 safety electric capacity, X2 safety electric capacity high pressure resistant smaller or equal to 2.5 kV; The electromagnetic interface filter common mode filtering performance that is used for electronic equipment power source usually receives the restriction of common mode capacitance.Because the size of leakage current is most important for life safety, country variant has all been done strict regulation to distinct electronic apparatuses earth leakage stream.If maximum leakage current has been made regulation, then demand goes out the maximum ground capacity value that allows.

In addition, require electric capacity that enough surpluses are being arranged aspect electric and the machine security, avoid under exceedingly odious condition, occurring the phenomenon of puncture short.Because this electric capacity will be with linking to each other safely, and the casing of equipment also will be with linking to each other safely, so the withstand voltage properties of this electric capacity has crucial effects to protection life safety, in case the failure of insulation of equipment or device possibly injure people's life security; And X2 safety electric capacity meets the requirements fully, and it allows can avoid occurring in exceedingly odious taking off the phenomenon of puncture short under the ground capacity value in the maximum that meets demand.

More than be merely the preferred embodiment of the utility model, be not limited to the utility model, any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection range of the utility model.

Claims

1. a capacitance-resistance filter is characterized in that, comprises resistance (R1), first electric capacity (C1), second electric capacity (C2), the 3rd electric capacity (C3);

Said resistance (R1) is cut-off frequency resistance, and said first electric capacity (C1) and second electric capacity (C2) are differential mode capacitor, and said the 3rd electric capacity (C3) is common mode capacitance;

Said resistance (R1) is parallel to the two ends of said the 3rd electric capacity (C3);

Said first electric capacity (C1) is with after second electric capacity (C2) is connected, and parallelly connected with said resistance (R1), said the 3rd electric capacity (C3) respectively.

2. capacitance-resistance filter according to claim 1 is characterized in that, said first electric capacity (C1) and second electric capacity (C2) are Y2 safety electric capacity, and said the 3rd electric capacity (C3) is X2 safety electric capacity.

3. capacitance-resistance filter according to claim 2 is characterized in that, the resistance of said resistance (R1) is 1 megaohm, and the appearance value of said first electric capacity (C1) and second electric capacity (C2) is 15000pF, and the appearance value of said the 3rd electric capacity (C3) is 0.1uF.