DE1158548B - Circuit arrangement of track circuits for railway security systems - Google Patents

Description

Circuit arrangement of track circuits for railway safety systems The invention relates to a circuit arrangement on track circuits for Railway safety systems, in which the individual track sections are opposite adjacent sections are insulated by insulating joints in such a way that the signal circuit between the individual sections is blocked, while a return line of the traction current is possible via reactive resistances at the insulating joints.

Which electrically isolate the individual signal circuit sections from one another Throttle surges represent relatively expensive pieces of electrical equipment of railways. The higher the frequency, the cheaper these throttle surges are of the signal currents used is because the inductance with the same inductive resistance of course, lower frequencies can be selected at higher frequencies. Increasing the However, the frequency of the signal currents is determined by the transmission properties of the rail tracks There are limits because the railroad tracks themselves have a relatively high inductance exhibit. The quality of a track power safety system for the occupancy of railways is caused by the axis short circuit that occurs between the rails and causes the trigger determined by the vehicle on the relevant track section. At high frequencies of the signal current this has an axis short circuit in the The proximity of the signal input of the relevant track section has a sufficient value, however, the amplitude decreases rapidly from here and reaches when the axle short-circuit is removed due to the high inductive resistance of the rails, it soon becomes impermissibly low Value.

The aim of the invention is to improve the operational safety of such railway safety systems to increase and to create the possibility with higher signal currents and therefore cheaper throttle shocks or to work with longer track securing sections.

For this purpose, a circuit arrangement is that mentioned at the beginning Design according to the invention in such a way that each section has a first transmitter arranged at its input E, which sends a signal stream of the characteristic Cl generated, as well as having a receiver arranged at its output S, which caused by the current of characteristic C1 to provide a second in S. The transmitter controls which the section between E and S with a signal stream of Characteristic C2 feeds, which is fed to a signal receiving device provided at input E, z. B. a relay, acts, and that by a located in the track section Axle short-circuit caused by the vehicle between input E of section and an intermediate point L of the section the signal current C, and between the intermediate point L and the output S of the section bypasses the signal current C2 in such a way that the signal current Cl in S or the signal current C2 in E is below the excitation level.

The switching arrangement according to the invention causes either the signal C1 is short-circuited through the axles of the train or the signal C2, as the case may be at which point of the track section the train is located. Over other The circuit arrangement according to the invention has track circuits for railway safety systems the advantage that the wheel axles causing the short circuit with respect to the effective Signal circuit with only half the series resistance of the rails of one Track section are in a row because on one half of the track section the signal stream C1 and on the other side of the track section the signal stream C2 is short-circuited. This will compare the amplitude of the effective signal to conventional railway safety systems under otherwise identical conditions larger, which has a beneficial effect on operational safety.

The signal currents C1 and C2 are different alternating currents Frequency.

The invention can be practiced in various ways. According to one embodiment, a generator can have a AC voltage with the frequency f 1 in the signal circuit, which at the output with one of another generator supplied frequency f. mixed and as an intermediate frequency fed into the signal circuit and fed to a selective circuit at the input. A frequency converter is expediently provided at the input to which the received Intermediate frequency and the frequency supplied by a local generator be, whereby from this frequency converter the trip circuit signals of a corresponding Frequency mixture are supplied.

According to a further embodiment, in which the currents Cl and C2 are continuous alternating currents of different frequencies, signals are generated at the input of the form f 1-f. generated and fed into the signal circuit, and at the output Signals of the form f.-f4 are generated and after mixing with the incoming signals in fed into the signal circuit. In this case, it is expedient to use the frequency f2 am Input generating generator connected to a frequency converter, which the at signals received at the input.

Instead, the signal currents C1 and C2 can also have alternating currents of the same type or of different frequencies, alternating in fixed or variable Rhythm in the rail circle flow, this rhythm being one of the rail circle can represent superimposed signaling. For this purpose one can enter at the entrance be provided by a clock controlled changeover switch, which the signal circuit alternately with a generator of an alternating current of frequency F or with the Trip circuit connects. A similar clock generator can then be provided at the output that controls another changeover switch and the signal circuit alternately connects to the receiver or a generator.

The terms "input" and "output" used in the description are purely conventional. The traffic on the track sections secured in this way can run in any direction.

Further advantages and details of the invention emerge from the following description of some exemplary embodiments with reference to the drawing. The fig. 1, 2 and 3 of the drawing show schematic circuit diagrams of the invention Circuit arrangement of track circuits for railway safety systems.

In the exemplary embodiments, only one track section is included One sender and one receiver at the beginning and one at the end. Of course the invention can also be used for several sections, with odd Number of transmitters and receivers the signal relay on the one opposite the primary supply End can be arranged.

The in Figs. 1 to 3 between the input E and the output S of the The lines of the track section indicate the railroad tracks. The ends these rails are galvanically separated between each two adjacent sections, are bridged by throttle surges, which have a high, for the traction current, however, represent a low resistance.

1 shows a track circuit which is connected to the next section at its input E or at its output S via a throttle shock of a type known per se. A secondary winding, via which the signal current can be fed in or removed in a known manner, is coupled to the choke coil of the choke shock, which is provided with a central tap. An alternating current generator A, which supplies a frequency f 1 , feeds the secondary winding at the input E via the amplifier B.

The alternating current of frequency f1 occurring in the secondary winding at output S is filtered at C and fed to a frequency converter D, which is simultaneously fed by a generator F with a frequency f 2. The composite current with an intermediate frequency Z f2-f 1 is filtered at G, amplified at H and then fed to the secondary winding at output S.

The alternating current of the intermediate frequency f2-fl is received in the secondary winding at the input E, filtered at I and fed to a frequency converter J , which is fed by a local generator K at a frequency f3. The composite current of frequency f3 + (f2-f,) is filtered at L and amplified at M. The resulting current flows through a highly selective filter N, for example of an electromechanical design, is amplified at 0 and finally fed to the signal relay R. In this embodiment, the local generator K can be omitted; the local supply is then taken from the generator A of the frequency f 1 and fed to the frequency converter J either directly or after doubling.

The current characteristics Cl and C2, here the frequencies f 1 and (f 2 -f 1) are chosen so that the current of the frequency f 1 between E and an intermediate point L, the current of the frequency (f2 - f ) between L and S. is effectively short-circuited when a vehicle is between E and L or L and S.

The arrangement according to FIG. 2 is described below. Certain highly selective ones Filters and oscillators, for example oscillators controlled by piezoelectric Quartz can only be produced for higher frequencies than those applicable to rail circles. The use of these highly selective elements forms the object of the signaling device according to Fig. 2.

Alternating currents with frequencies f 1 and f 2 that are generated in generators A1 and A2 and fed to the frequency converter P are fed into the rail circuit via the secondary winding at input E in generators A1 and A2 after amplification at B. A current of frequency f 1- f2 therefore flows on the rail track.

The absorbed in the secondary winding S and filtered in the filter C. Alternating current of frequency f 1- f., Is fed to the frequency converter D, which is on Location of generators F3 and F4 fed with alternating currents of frequency f3 and f4 will. The frequency converter S2 supplies an alternating current of the frequency f3-f4.

Among other things, a current flows at the output of the frequency converter Frequency (f 3 - f 4) - (f1 -f2), which is filtered in G, amplified in H and then is fed back to the secondary winding at output S.

The corresponding one recorded in the secondary winding at input E. Current is filtered in 1 and fed to the frequency converter J, which is also supplied by the generator A2 is supplied with a frequency f2. At the exit of the frequency converter J flows, among other things, the current of the frequency f 2 in the highly selective filter N filtered, amplified at O and then fed to the relay R. will. In Fig. 3, a signal device according to the invention is shown at which the alternating currents with the characteristics Cl and C, alternating in the rail circuit flow.

The with the secondary winding of the half-impedance bridge at the input E of the Rail circuit related device has a changeover switch Q1 on, which is controlled by a clock T1 and alternately the secondary winding the half-impedance bridge with a generator delivering a current at frequency F. A or with one consisting of an amplifier N, a filter O and the relay R. Circuit arrangement connects. The filter O can be a simple or a highly selective one Be a filter; in this case a frequency converter with a local generator can be used upstream.

At the output S a changeover switch Q is provided, which is controlled by a clock T2, which in turn is set in motion by pulses from the receiver U. The switch connects the secondary winding of the half-impedance bridge alternately with the receiver U or with a generator Y of an alternating current of frequency F.

According to the timing, the generator A feeds the rail circuit during the odd fractions of the measure. The device at output S receives this Arousal and causes a response during the even fractions of the measure same frequency. The corresponding current actuates the relay R.

According to the respective requirements, the timing can either with constant frequency, the relay R then a delay device can have, or it can be done at variable frequency to vehicles or to transmit signals to the opposite end of the track circuit.

Claims (9)

PATENT CLAIMS: 1. Circuit arrangement of track circuits for railway safety systems with track sections isolated from the adjacent sections by means of insulating joints, characterized in that each section has a first transmitter at its input (E) which generates a signal current of the characteristic (C) and has a receiver arranged at its output (S) which, caused by the current of the characteristic (Cl), controls a second transmitter provided in (S), which transmits the section between (E) and (S) with a signal stream of the characteristic ( C,) feeds, which is fed to a signal receiving device provided at the input (E), e.g. B. a relay acts, and that the axle short-circuit caused by a vehicle located in the track section between the input (E) of the section and an intermediate point (L) of the section, the signal current (Cl) and between the intermediate point (L) and the output (S) of the section bypasses the signal current (C2) in such a way that the signal current (Cl) in (S) or the signal current (C2) in (E) is below the excitation level. 2. Circuit arrangement according to claim 1, characterized in that the signal currents (Cl and C ") are alternating currents of different frequencies. 3. Circuit arrangement according to claim 2, characterized in that a generator (A) at the input (E) AC voltage with the frequency (f1) feeds into the signal circuit, which at the output with a frequency (f.) supplied by a generator (F) and mixed as an intermediate frequency (f2-fl) fed into the signal circuit and fed to a selective circuit at input (E) becomes (Fig. 1). 4. Circuit arrangement according to claims 2 and 3, characterized in that a frequency converter (J) is provided at the input (E) to which the received intermediate frequency (f2-fl) and the frequency (f3) supplied by a local generator (K) are fed and that from this frequency converter the trigger circuit signals in the form (f. -I- f 2 - f ) are fed (Fig. 1). 5. Circuit arrangement according to claims 1 and 2, characterized in that at the input (E) signals of the form (f l- f2) are generated and fed into the signal circuit that at the output (S) signals of the form (f3-f4) and after mixing with the incoming signals in the form (fl-f,) - (fß-f4) are fed into the signal circuit (Fig. 2). 6. Circuit arrangement according to claim 5, characterized in that the generator (A2) generating the frequency (f2) at the input (E) is connected to a frequency converter (J) to which the signals received at (E) are fed and which is fed to the trip circuit accordingly signals of the form. f2 + (f3-f4) - (fl-f,) supplies (Fig. 2). 7. Circuit arrangement according to claim 1, characterized in that the Signal currents (Cl and C2) Alternating currents of the same or different frequency that flow alternately in a fixed or variable rhythm in the track circle, this rhythm representing a signaling superimposed on the track circle can (Fig. 3). B. Circuit arrangement according to Claim 7, characterized in that a changeover switch (Q1) controlled by a clock generator (T1) is provided at the input (E) is that alternates the signal circuit with a generator (A) of an alternating current the frequency (F) or connects to the trip circuit (Fig. 3). 9. Circuit arrangement according to claims 7 and 8, characterized in that a by a clock (T2) controlled changeover switch (Q2) is provided at the output (S), which in turn is set in motion by pulses supplied by the receiver (U) and that the switch connects the signal circuit alternately with the receiver (U) or with a generator (Y) (Fig. 3). Documents considered: German Patent No. 918 991; French patent specification No. 1 120 555.