DE918348C - Circuit arrangement for generating voltage curves, which are used in particular for flicker-free operation of incandescent lamps from low-frequency networks - Google Patents

Description

Circuitry for generating voltage curves which is particularly suitable for flicker free operation of incandescent lamps of nets low frequency serve additional patent 916 7 81 subject of the patent 916 781 a circuit arrangement for generating voltage curves, in particular for flicker free operation lower incandescent of nets frequency, z . B. in railway systems from networks of 1627 "Hz, using an iron-saturated choke coil in cooperation with an unsaturated choke coil The autotransformer located at the base frequency and at the connection point of the two choke coils. By appropriately designing the tap of the autotransformer with the inclusion of a choke coil of suitable size at the end of the autotransformer, the autotransformer becomes superfluous, while the additional choke with one of the two The first-mentioned chokes are used together in a transformer circuit.

In a further modified circuit according to patent g16 78I the fundamental wave for Power output in such a way that that the voltage is three times the frequency of one over a starting point on a transformer extracted voltage of the fundamental frequency is superimposed in such a way that the superposition results in a saddled voltage curve whose transition from positive to negative values occurs very steeply through the zero value.

These circuits give at constant mains voltage and more consistently Mains voltage waveform and a satisfactory one at constant load Operation. It is different, however, when all three operational variables are changeable; `call z. B. the relative position of the fundamental waves against the harmonics shifts, z. B. because the network itself generates harmonics, then there may be a composite Tension curve came about with a pronounced tension spike and a very gradual zero crossing of the voltage curve.

Such a tension course must of course be strong Produce flicker. To counter this drawback, according to the invention in the consumer circuit can also be regulated by a choke coil or a capacitor Size or variable connection to taps of a choke or a transformer or a converter switched on. When the capacitor z. B. with the consumer, So if the incandescent lamps are in series, it is conveniently connected to a current transformer. The current transformer can of course be connected in an economy circuit. By doing if this current transformer is provided with taps, the respective state can be determined adjust easily, so that a flicker-free operation is possible.

Fluctuations in the voltage level of the network can thereby be balanced be that the unsaturated choke at which the voltage for the consumer is balanced, is also provided with taps. Recommended in many cases the coupling of the setting of the current transformer tapping with the setting the throttle tap.

According to the invention, the circuit is further simplified in such a way that that a desired voltage curve, namely one from a fundamental frequency and from superimposed on a triple harmonic, directly from the unsaturated choke coil taken in series with a saturated iron choke of suitable size is connected to the grid. With this arrangement, the fundamental wave becomes so to speak retain the triple frequency harmonic in the iron-saturated choke, the absence of which then generates the desired voltage curve in the unsaturated choke.

The circuit is then explained using the illustrations. It mean L1 and L2 are the two series-connected inductors, from where L1 represents the iron-saturated coil. At the unsaturated choke coil L2 then generally becomes a voltage curve due to the voltage developed across L1 generated, which is shown in Fig. 2. This is suitable for the operation of an ordinary Glow lamp.

By shifting the triple harmonic it can now happen that a voltage curve shown schematically in Fig. 3 arises. To now Bringing the fundamental and harmonic back into the correct phase relationship is according to Fig. 4. in which a feed line to the consumer is connected a current transformer St, which feeds a capacity C. By providing the current transformer with taps, the conditions can be adjusted by changing the taps. In fig. 5 the further feature is brought to the representation, after which the capacitor over a current transformer in economy circuit is tapped, while at the same time the voltage can be tapped in the unsaturated throttle L2 via taps A1, A2, A3.

The aggregate of current transformer and capacity can of course can also be used for the other circuits according to the main patent.

Instead of switching on a capacitive load in series with the incandescent lamp, A throttle flush L3 as shown in Fig. 6 can also be switched on in parallel. Then can the current transformer come in failure. This second choke coil L3 should also can be tapped or changed in terms of saturation, so that a relative Shift in phase from fundamental or harmonic can be set to one Curve according to Fig. 2. A particularly simple continuous regulation results by changing the air gap.

Another possibility of setting is given as shown in Fig. 7, that instead of the inductor L3, a capacitor C is connected, which either itself is variable or to a variable tap of the inductor L2 to be led. The incandescent lamp load G should also be at different tapping points Choke coil can be connected. The respective combination of the effective load through G and the reactive load through C also gives the possibility of the voltage curve to be adjusted according to Fig. 2 for all network conditions.

The flicker-free operation of the connected incandescent lamps can be achieved through Photo elements are monitored, which at the same time also automatic adjustment can cause. The various control taps are appropriately coupled, whereby the adjustment process is simplified.

Claims (7)

PATENT CLAIMS: e.g. Circuit arrangement for generating voltage curves, which are particularly useful for the flicker-free operation of incandescent lamps from low-frequency networks, e.g. B. in railway systems from networks of i6213 Hz, are used, using an iron-saturated choke coil in cooperation with an unsaturated choke coil, both of which are connected in series to the low-frequency network and which are tapped on an autotransformer or by combination with control chokes or with an additional Transformer either produce a pure harmonic of three times the frequency or the superposition of one with the fundamental frequency in such a way that with this superposition a voltage form is created which changes very quickly from a high positive to a high negative value and vice versa, according to patent 916 781, characterized in that for the adjustment of network fluctuations both with regard to the voltage level and with regard to the occurrence of harmonics as well as with regard to the shift of the relative phase position of fundamental wave against harmonic in the incandescent lamp circuit, additional capacitors or inductors develop Either adjustable size or variable connection to taps of the unsaturated choke coil are provided. 2. Circuit arrangement according to claim i, characterized in that that the unsaturated choke coil (L2), without the aid of a transformer, for example or another tapping throttle to draw the light bulb current. 3. Circuit arrangement according to Claims 1 and 2, characterized in that a capacitive Load is in series with the incandescent lamp load, which is useful over a connected with taps on the primary and / or secondary side is. q .. Circuit arrangement according to Claim 3, characterized in that a current transformer is used in economy circuit. 5. Circuit arrangement according to claim i and 2, characterized characterized in that parallel to the incandescent lamp load a variable or with Taps provided choke coil (L3) is connected. 6. Circuit arrangement according to claim i and 2, characterized in that an optionally variable capacitor ( C ) is connected in parallel to the incandescent lamp load, it being useful for both the incandescent lamp load and the capacitor to be connected to desired taps of the unsaturated choke (L2). 7. Circuit arrangement according to claims i to 6, characterized in that the change in the circuit sizes to adapt the operation to the network and load sizes, e.g. B. the switchover the lamp load as well as switching the voltage level of a choke or a capacitor od. The like., Is coupled to one another.