DE241378C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- M 241378 CLASS 21 d. GROUP

Patented in the German Empire on January 4, 1910.

In practice it is often desirable to have electrically generated magnetic fields as quickly as possible to bring to the maximum excitation value. So far, various circuits have been used for this purpose applied, in which the winding of the field at the beginning of the switch-on to a higher voltage is applied than during operation, for which either a special power source with variable tension is required, or the permanent annihilation of one Part of the voltage due to series resistors during operation. Around To make the task at hand clearer, let us use the as an example of rapid excitation Drive motor of a conveyor machine operated in a Leonard circuit or a reversing roller train called whose field can only be completely switched off during work breaks may, if a rapid excitation enables the rapid achievement of the full field strength when switching on again and starting guaranteed.

In fact, up to now, such machines have always only been connected by means of an upstream resistor achieved low field weakening in. Allowed the breaks while applying a high-speed excitation would require a shutdown of the field, which when using the known means, however, requires the arrangement of a special exciter.

The present invention is intended to provide rapid excitation of a motor, a dynamo machine or other magnetic fields without energy loss in resistors and with constant supply voltage enable the excitation, namely the known Spraguesche circuit the series and parallel connection of field coils for the purpose of field weakening serve for temporary overexcitation of the magnetic field.

The Sprague circuit has so far only been used for temporary field weakening for motors Found a use to increase the number of tours. The field coils for parallel connection must therefore be dimensioned there will be like a normal, fully saturated machine while for normal Operation series connection is used and which acts just as if the field weakening would be made by resistances.

Essentially, a machine must be available which is in normal operation with a weakened field and therefore reduced efficiency works to help them at times to be able to work with a stronger field.

The invention now uses the fact that one is in operation for rapid excitation machine working in full excitation at the moment of switching on its excitation or their increase to the full value as a result of the self-induction does not immediately cover the full field receives, which can therefore still be increased during this time, through appropriate Parallel connection of the field coils temporarily until after full excitation has been achieved an increase in the ampere-turns bring about.

In Fig. Ι the drawing, the invention is dar-

Claims (2)

posed. According to this, the winding of the magnetic field, e.g. B. a DC dynamo or a motor, divided into two parts α and b, which can be switched differently by the switch c. Fig. 2 shows the switching of the magnet winding effected in the positions of the switch I, II and III. The transition from one circuit to the other takes place without interruption ίο the circuit. The circuit shows a two-stage control of the number of ampere-turns without the use of resistors, of which z. B. the first stage can have twice the value of the second. For quick excitation of an inductive coil, circuit III is used at the moment of switching on, from which circuit I is produced after complete excitation of the coil through a mere transition through circuit II. At the first moment, with the voltage remaining the same, the number of ampere turns is twice as large as in circuit II or I, assuming that the two coil parts are of the same size, whereby the energization time of the coil is shortened. The transition from circuit III to circuit I takes place only after it has been fully excited, which results in a reduction in the number of ampere-turns. Although the coils are overloaded at the moment they are switched on, this is harmless due to their short duration. In order to avoid too long an overload or a premature transition into the circuit I, the device can be made so that the shift lever is tightened by a spring which is tensioned by the hand lever, a locking device keeping the shift lever in the circuit for so long III holds until the required magnetization strength of the coil is reached, after which the release of the shift lever and thus its actuation takes place. The locking device can be influenced in the simplest way, either by the current strength of the coil or by the field strength of the same, after both the current and the magnetization only gradually increase to a desired value due to the influence of the counter induction of the coil. Fig. 3 shows the circuit in an expanded version with further subdivision of the coils. Godparents τ-A ν saying: 1. Circuit for lossless high-speed excitation of subdivided field coils at unchanged supply voltage of the same, characterized in that the individual Parts of the coil are connected in parallel for a short time in the case of high-speed excitation Purposes of producing different ampere-turns numbers that are appropriate for operational excitation or high-speed excitation. 2. Circuit according to claim 1, characterized in that the switching of "Fast excitation" on "Operation" depending on the speed caused by the high-speed excitation ■ the magnetization strength reached is blocked or carried out automatically, so that the overstressing of the winding is not switched off prematurely or not take unnecessarily long. 1 sheet of drawings.