DE1787012C3 - Variable equalizer - Google Patents

Description

1 / (ί RJ + 4R " · Κ_- (K- + R ") Has, wherein Pure 2
and ' Rough ·. ^l "R Pure R ₂ - t "R.ii_ ί. + is applicable
ti ' 1 +

and where the amount of transmission of the system as a whole to a simple or constant multiple by a constant of a special Frequency characteristic is set by changing the value of the transfer coefficient.

or constant multiple

TSaftfÄ ^ the he »

are described in the hand of the drawing

1 is a schematic diagram of a variable Em- 'according to the invention,

Fig τι a circuit diagram of a practical Ausführungsunßsforö the variable equalizer of F i & 1,
Fig. 3 is a circuit diagram of a weather execution

^fO ™ g ° 4 a representation of the frequency characteristic of the

^A GemaTFi ^f g ™ S ^h dev ^ ^g ariable equalizer between the terminal pair 1-1 'and the terminal pair 2-2. Mh E is a constant voltage source, with R ₁ eme energy source _{impedance and R 2} a load impedance

Embossing from the pair of clamps 3-3 'to the pair of Memmenpaar 4-4', and g {,.,) Ι is the short-circuit transfer admittance of the circuit /! be, one

Angular frequency, -, ■ R _n -. denotes the input impedance, Rj denotes the output impedance and R denotes e cycle resistance, which is inserted into a feedback path of the circuit A.

The effective transfer coefficient of the four

pols (variable equalizer) in FIG. 3 can now be done as follows can be expressed:

35

R + R + R '

wherein

"_ JVJ__

"R ₁ + Re

The invention relates to a variable equalizer having a circuit with a transfer coefficient of the desired frequency characteristic, with a circuit whose transmission coefficient is in its Value can be changed arbitrarily, and with a circuit that has only one-way transmission.

It is an equalizer, so-called Bode equalizer,
known, in which the reflection of the impedance at a
separate pair of terminals of a quadrupole used 45 ""

will. The attenuation or the gain R _h - —1 - -so?

of the quadrupole changed by adding a corresponding ^ 2 + R _IIU

measured resistance is switched to the separate pair of terminals. In this training it is just a matter of fact.

possible to use the equalizer in positive direction and not 50 if the following condition

to vary in the negative direction.

In contrast, the invention provides that in _R

a variable equalizer with an input pulse K = 1 - t.

danz R _a , with an output impedance /? "" ,, with an R + R _n + 1

Power source _{impedance R 1 associated} with the input 55, ■

side of the variable equalizer, and with

a load impedance of the output side R ₂ a pure, -— - ^ - Tp ~ ""'"p"

Resistance between the output side and the ^ _ ._'_! ._ »._ Ξ .._____ ..? _? ^h .. "T ..

Input side of the variable equalizer is switched. 2

the resistance value

R =

R _h f + 4R „ ■ R _b - (R _a

added to equation (1)
Equation can be written as

. + R _t ) (3), this can

has where

rlit

^and

6s 2R
R ₁

1 +

K ₁ + Κ-, - Λ ₂ -Γ n _m ,

and what «the amount of transfer of the system and the amount of effective transfer

(4) can

can be expressed as

Equalizer, the amount of which the transmission β can be expressed as:

θ =

= In ^ ¹ + 2R »+ =

From equation (5) it can be seen that the amount of the transfer, with the exception of a constant amount

of In% - is proportional to g (oj) in a range,

in which the higher order terms can be neglected, and accordingly it becomes possible if g (<u) in an expression with the desired Frequency characteristic and another expression is divided, its value into an arbitrary constant Multiple or simple can be changed by a constant, the amount of the transfer in Set the ratio to the frequency characteristic of the previous printout by changing the last printout and thus can become a so-called variable equalizer.

In FIG. 2, which shows a simple embodiment of the invention, A ₁ denotes a circuit whose transmission coefficient (k) can be set arbitrarily. A ₂ denotes a circuit whose transmission value has a predetermined frequency characteristic, and «(«>) is the transmission factor of the circuit A ₂ with respect to the angular frequency (.). Ai denotes a broadband amplifier which has no frequency characteristic, and g ₀ is the short-circuit transmission admittance of the amplifier. When the impedance that can be matched between A ₁ and A ₂ and between A ₂ and A _{1 has} been reached, circuits A ₁ , A ₂ and A _{2 lead} the operation of circuit A of FIG. 1 off and the short-circuit transmission admittance can be expressed as:

g (m) = fc · "(,") · _go (6)

and accordingly, under the condition of equation (2) or (3), equation (5) can be written as:

(-) = In 4P + 2R

a {m) ■ go, -

(7)

and it is possible to change the amount of transfer θ in relation to «(«>) by changing k . F i g. 3 shows a further embodiment of the invention, which relates to a so-called multi-variable in which M pieces with an independent characteristic («j can be changed independently of one another. FIG. 4 shows the frequency characteristic of the amount of excess

transmission at the point in time when independent characteristic curves are the maximum amplitude. In F1 g. j denotes A a broadband amplifier. The input impedance of this amplifier is cc, R _ns j _s t is the output impedance and g _? is the short circuit

»5 Transmission admittance, with no frequency characteristic. B denotes an isolating network which is constructed in such a way that the input can be an almost constant resistance. R _cill denotes the input impedance of the circuit, R ₀ denotes the terminator of the partial filters, and R 'denotes the resistances which connect the sub-filter having the circuit A. These resistors R 'have high resistance _{values which satisfy the condition of R 0} <c R' and work as potentiometers.

to decrease the tensions at the two ends of R ₁ . If the voltage transfer coefficient e.n of the sub-filter is α, (ω) (i = 1.2 ... M) and the potentiometer's position is / c, (0 <fc, <1). the short-circuit transmission admittance from the input of the separation network B to the output of the amplifier A can be expressed as

go

and the amount of effective transmission of the entire circuit can be expressed as

ψ £

(10)

and the effective attenuation can be expressed as

R ₁

. (Ii]

where Re («,) is the real part of«, · and the characteristic. as shown in Fig. 4, when fe. = 1 (i = 1 ~ M) .

If ic, - is changed, a multivariable

Equalizer can be set up in which the amount of transmission is changed by a frequency characteristic which can be proportional to each curve of FIG. 4 is.

1 sheet of drawings

Claims (1)

Claim: Variable equalizer with a circuit with a transfer coefficient of the desired frequency characteristic, with a circuit whose transfer coefficient can be arbitrarily changed in its value, and with a circuit which has only one-sided transmission, characterized in that with an input impedance R _ei " , with an output impedance R ₀₁ - with a power source impedance R ₁ connected to the input side of the variable equalizer, and with a load impedance R _{2 of} the output side, a pure resistor connected between the output side and the input side of the variable equalizer, the Resistance value