DE1462221B2 - SAVINGS TRANSFER WITH MULTIPLE TAPS - Google Patents

Description

1 + k 1 + k ²

and

k · (1 + k) 1 + k ²

lie.

2. Economy transformer according to claim 1, characterized in that the resistance to be translated is a capacitive resistor.

F i g. 1 shows an economy transformer with which a downward translation can be carried out. For the sake of simplicity, only the ohmic resistance Rl is shown as the load resistance, to which one would have to think of the fixed capacitance to be translated in each case connected in series. However, this capacitance can initially be disregarded for the consideration of the changes in effective resistance when the respective taps change.

ίο For the sake of simplicity, the transformer is only shown as an economy transformer with two windings. The windings L ₁ and L ₂ ^m 't with the number of turns It ₁ and / 7 ₂ are intended to be resistance-free, and the ohmic resistance associated with the respective windings is shown separately and denoted _{by T 1} or r _{2, depending on the winding association.} The total ohmic resistance occurring at the respective tap should be denoted by r '. Considerations within the scope of the invention have shown that the resistance r 'can be expressed by the following formula:

1 + k 1 + k ²

and

■ k)

₅ o

The invention relates to an economy transformer with several taps and a ratio k between the upper and lower limit values of a selectable transmission ratio, as well as a resistance to be translated.

In the course of downsizing the devices one makes, for. B. in replica assemblies, for the realization of changeable capacities more and more use of the translation of fixed capacities by saving transformers with multiple tapped windings. These taps make it possible to change the transmission ratio ü and thus also to set the translated capacity to the values required in each case. Unfortunately, when the taps are changed, the effective resistance caused by transmission losses also changes with the capacity. This becomes larger and larger as the size of the transformer becomes smaller and accordingly requires more and more attention. In addition, the loss resistance is increasingly determined by the winding resistance, which means that it is approximately proportional to the number of turns.

The object of the invention is to create a saving transformer in which when the taps are changed To adjust the capacitance, the real part of the impedance is influenced as little as possible.

The economy transformer is dimensioned according to the invention in such a way that the individual transmission ratios between the values

r = r.

«1 +« 2

Rl)

«1 +« 2

If one assumes that there is only a pure capacitive resistance on the secondary side, the resistance Rl is equal to 0, and the ' ^J formula is then simplified''toί; π · ·

If you put this resistance in relation to the total ohmic resistance of the secondary side, the normalized resistance ρ 'is thus obtained

F i g. 2 shows the circuit diagram for a transformer with a step-up ratio. The designations ent-40. speak the designations according to Fig. 1. The corresponding winding resistance occurring in the respective primary-side tap, which should be designated with r " for upward transmission, results from the following formula:

r = r-,

r ₂ ,

again assuming that the ohmic load resistance Rl is equal to. The associated normalized resistance then has the function ρ '= ü (ü - 1).

In the diagram according to Fig: 3 are the normalized Resistances ρ 'and ρ "depending on the respective

Gear ratio - plotted. One sees,

lie. On the basis of this dimensioning, we get that each is a parabolic function.

rSSSÄÄiS "" WahKn ^ dasVerMHnisiungefahrgHchl, where

Using the circuit diagrams according to FIGS. 1 and 2 60 «p the number of primary turns and n _s the respective seconds

as well as the diagram according to FIG. 3 will mean the invention number of turns, so will the resistance

explained in more detail. a minimum.

1 sheet of drawings

Claims (1)

Patent claims: 1. Economy transformer with several taps and a ratio k between the upper and lower limit value of a selectable transmission ratio and a resistance to be translated, characterized in that the transformer is dimensioned so that the individual transmission ratios between the values