CN106027023A - Voltage division circuit outputting constant impedance - Google Patents

Abstract

The invention discloses a voltage division circuit outputting constant impedance. According to the invention, in a manner of substituting resistors with a circuit, output impedance of the voltage division circuit can be constant, such method is relatively simple to realize, and can be realized just by forming that three resistors in the circuit satisfy a certain relationship. Moreover, output voltage of the voltage division circuit can be obtained quickly.

Description

A kind of bleeder circuit exporting constant impedance

Technical field

The present invention relates to electronic technology field, be specifically related to a kind of bleeder circuit exporting constant impedance.

Background technology

At electronic technology field, bleeder circuit is a kind of very important basic element circuit, is widely used in Output signal regulation, gain control etc..

The most common bleeder circuit is the mode using resistant series dividing potential drop, as shown in Figure 1.This Dividing potential drop mode is simple, but when adopt in this way voltage is carried out Multilevel partial-pressure when, its output impedance is not For steady state value.As in Fig. 1, A point output resistance is 2R, and B point output resistance is R.

Summary of the invention

In view of this, the invention provides a kind of bleeder circuit exporting constant impedance, it is possible to realize equal proportion The output constant impedance of bleeder circuit.

A kind of bleeder circuit exporting constant impedance, if n level bleeder circuit, including voltage input end, ground connection End and 2n resistance；

Wherein, 2n resistance by a resistance equal to the resistance Z of R₀, n resistance be equal to the resistance Z of R1₁With N-1 resistance is equal to the resistance Z of R2₂Constitute；And

Voltage input end is sequentially connected in series n resistance Z₁After, then by resistance Z₀Ground connection；Adjacent resistor Z₁Between, By a resistance Z₂It is connected to ground；Adjacent resistor Z₁Between common port and resistance Z₁With resistance Z₀Between Common port, respectively as the outfan of bleeder circuit, and output end voltage is V_i=kⁱ× V, wherein, i generation Table level number, i=(1,2 ..., n) wherein, k is dividing potential drop coefficient,During use, according to required electricity Pressure, selects corresponding outfan.

Beneficial effect:

The present invention is by the way of using circuit to replace resistance so that the output constant impedance of bleeder circuit, this The method of kind realizes relatively simple, it is only necessary to constituting in this circuit three resistor satisfied certain relations can realize. And can quickly obtain the output voltage of bleeder circuit.

Accompanying drawing explanation

Fig. 1 is prior art resistant series bleeder circuit.

Fig. 2 is one-level bleeder circuit in the present invention.

Fig. 3 is the alternate figures of resistance R in the present invention.

Fig. 4 is two grades of bleeder circuits in the present invention.

Fig. 5 is bleeder circuit figure of the present invention.

Fig. 6 is embodiment bleeder circuit figure in the present invention.

Detailed description of the invention

Develop simultaneously embodiment below in conjunction with the accompanying drawings, describes the present invention.

The invention provides a kind of bleeder circuit exporting constant impedance；Its main thought is: such as Fig. 2 institute The bleeder circuit figure that one-level ratio is k shown；Between voltage input end and ground, series resistance Z₀And Z, Its resistance value is respectively R and R1, then at resistance Z and Z₀Between the dividing potential drop coefficient k of output terminals A be then:

$k=\frac{R}{R+R1}---\left(1\right)$

The voltage V of outfan_AIt is multiplied by dividing potential drop coefficient for input voltage:

$V_A=k\×V=\frac{R}{R+R1}\×V---\left(2\right)$

Wherein, V is input electricity；

Now, the output impedance of input A is R；

When needs realize two grades of dividing potential drops, in order to ensure that output impedance is constant, resistance R is entered by the present invention Go deformation as shown in Figure 3；As shown in Figure 4, resistance is the resistance Z of R₀' and resistance be the resistance Z of R1₃ Two ends, resistance in parallel is the resistance Z of R2₂, and

$R=\frac{R2\×(R+R1)}{R+R1+R2}$

It is to say, use circuit as shown in Figure 3, replacing resistance in Fig. 2 is the resistance Z of R₀', formed Fig. 4；This have the advantage that: in the bleeder circuit after replacement, resistance Z₀' and Z₃Between outfan B Output impedance be still R；The voltage V of outfan B now_BFor:

V_B=k × k × V

To sum up, when needs realize n level dividing potential drop, then according to above-mentioned theory, by the resistance in n-1 level bleeder circuit After the resistance that resistant series resistance is R1 that resistance resistance is R that value is R, then in its two ends parallel connection resistance For the resistance of R2, andAnd to keep resistance be R resistance one end ground connection.

Specifically: as it is shown in figure 5,

If n level bleeder circuit, including voltage input end, earth terminal and 2n resistance；

Wherein, 2n resistance by a resistance equal to the resistance Z of R₀, n resistance be equal to the resistance Z of R1₁With N-1 resistance is equal to the resistance Z of R2₂Constitute；Voltage input end is sequentially connected in series n resistance Z₁After, then pass through Resistance Z₀Ground connection；Adjacent resistor Z₁Between, by a resistance Z₂It is connected to ground；Adjacent resistor Z₁Between Common port and resistance Z₁With resistance Z₀Between common port, respectively as the outfan of bleeder circuit

Relation between resistance R1, R2 and R is:

$k=\frac{R}{R+R1}$

And:

$R=\frac{R2\×(R+R1)}{R+R1+R2}$

Wherein,

K is dividing potential drop coefficient；

Now, the output voltage of the n-th step voltage outfan is:

V_i=kⁱ×V

Wherein, i represents progression, and i=(1,2 ..., n)；During use, according to required voltage, select the most defeated Go out end.

Embodiment:

The constituted mode of circuit is: as shown in Figure 6:

1. resistance Z₀、Z₂、Z₄End points 1 ground connection；

2. resistance Z₁End points 1 and resistance Z₀End points 2 connects, resistance Z₁End points 2 and resistance Z₂End points 2 is even Connect；Resistance Z₃End points 1 and resistance Z₁End points 2 connects, resistance Z₃End points 2 and resistance Z₄End points 2 connects

3. resistance Z₅End points 1 and resistance Z₄End points 2 connects, resistance Z₅End points 2 is as voltage input end.

By this connected mode, constitute circuit diagram as shown in Figure 5.Then in this circuit, tri-end points of A, B, C divide It is not the 1st, 2,3 step voltage outfans.

According to each resistance relation, can calculate the impedance between A end points and earth terminal is R, output Voltage is V_A=V*R/ (R+R1)=V*k；Can calculate B end points output voltage further is V_B=V_A* R/ (R+R1)=V*k²；C end points output voltage is V_C=V_B* R/ (R+R1)=V*k³；And output impedance It is equal to R.

In sum, these are only presently preferred embodiments of the present invention, be not intended to limit the guarantor of the present invention Protect scope.All within the spirit and principles in the present invention, any modification, equivalent substitution and improvement etc. made, Should be included within the scope of the present invention.

Claims (1)

1. the bleeder circuit exporting constant impedance, it is characterised in that set n level bleeder circuit, including electricity Pressure input, earth terminal and 2n resistance；

Wherein, 2n resistance by a resistance equal to the resistance Z of R₀, n resistance be equal to the resistance Z of R1₁With N-1 resistance is equal to the resistance Z of R2₂Constitute；And

Voltage input end is sequentially connected in series n resistance Z₁After, then by resistance Z₀Ground connection；Adjacent resistor Z₁Between, By a resistance Z₂It is connected to ground；Adjacent resistor Z₁Between common port and resistance Z₁With resistance Z₀Between Common port, respectively as the outfan of bleeder circuit, and output end voltage is V_i=kⁱ× V, wherein, i generation Table level number, i=(1,2 ..., n) wherein, k is dividing potential drop coefficient,During use, according to required electricity Pressure, selects corresponding outfan.