Signalling transformers and filters

Signalling transformers are designated for power supply of signalling devices.

Key characteristics

• double insulation (withstand voltage up to 3000 V);
• low power consumption in an idling mode (from 30 to 50% lower than the one of analogs);
• life is 20 years;
• brass connecting elements (electric contact of high quality).

FR-50 resonant filter is designated to protect track circuit equipment against impact of reverse traction current with frequency 50 Hz on sections with AC electric traction./span>

Key characteristics

• FR-50 is a series connection of inductance and capacity being a resonant circuit adjusted to traction current frequency 50 Hz. At ALS current frequency 25 Hz, the filter is capacitive in effect, which partially compensates inductive current of magnetization of a feeding transformer;
• FR-50 is not an additional load for track circuit modules, as it has high resistance at information frequencies;
• use of the filter is especially topical for high-speed or heavy-freight lines, as well as lines with bad traction current plumbing.

Power supply sources for rolling stock and signalling

SRPA “Impulse” develops and manufactures power supply sources for any industry branches, including according to customer’s technical requirements. On-board power supply sources and power supply sources of signalling devices are manufactured for railways.

The SPN-33 power supply source is designated for power supply with voltage 24 V of not critical loads on a rolling stock with an on-board network 110 V.

It can be used on the following rolling stock types: 2TE116U, 2TE116UD, 3TE116U, EPL2T, EPL9T, DEL-02, etc.

The BPt-224, BPt-225, BPt-226 power supply sources of critical users are designated for power supply of on-board safety systems, rolling stock control systems with any voltage value of a standard-line on-board network (24/50/75/110).

Output voltage of the sources is galvanically isolated and stabilized, with rated values 26 V, 48 V, and 50 V.

The SPN-42 power supply source is designated to assure power supply of signalling devices with rated DC voltage 15 V and load current 5 А.

The BKTU-1 leak current monitoring unit is designated to increase operating safety and life of electric facilities, sudden outage of which can cause negative consequences and unreasonable material costs. According to the international classification it belongs to RCM-devices (Residual Current Monitor), which detect leak current and warn on this without power-off (as opposed to classic protective cutout devices).

BKTU-1 assures monitoring of up to 12 circuits and has two adjustable thresholds of leak current monitoring. When achieving the first threshold, it doesn’t stop operation, but generates a warning, allowing personnel to end a technological process correctly.

BKTU-1 is connected with the BKSI-2 insulation resistance monitoring unit via two-wired bidirectional RS-485 interface, which assures the possibility to transmit diagnostic information on monitored circuits.

Use of insulation monitoring devices is regulated with Electrical Installation Regulations (PUE).

The BKSI-2, BKSI-3 insulation resistance monitoring units are designated for automatic monitoring and online indication of electric insulation resistance in AC and DC electric networks with leak capacities of a measured circuit:

• BKSI-2 – up to 500 μF (divided circuits);
• BKSI-3 – up to 20 μF (linear circuits).

They have two adjustable resistance thresholds. As a control point for each threshold is achieved, independent discrete signals of “dry” contact type are generated, the signals are accompanied with a light signal. BKSI-2 has output to an RS-485 interface.

The PCht-2 and PCht-3 frequency converters are designated to power track circuits with phase-sensitive receivers with current 25 Hz. PCht-2 is designated to power circuits 110 (115) V, PCht-3 – to power circuits 220 (230) V. The converters have been developed to replace obsolete PCh-50/25 ferroresonant converters.

Key characteristics

• mass-dimensional parameters of devices have been reduced more than twice;
• phasers have been excluded from the power supply scheme of RC;
• a built-in function of synchronization of a group of devices (master/slave mode);
• a phase-shift angle is changed with one button pressing, possible phase-shift angles are 0, 90, 180, and 270 °;
• online indication of supply voltage and a phase-shift angle on each converter;

Based on these converters a modern panel of converters is composed (a functional analog of PP25.1) exceeding analogs by several main characteristics:

• coefficient of efficiency – 90 % (coefficient of efficiency of an analog is less than 50%);
• one panel assures power supply of phase-sensitive track circuits of a large station up to 120 conventional switches;
• self-diagnostics and continuous monitoring of state of insulation of cable networks indicating a problem section.