Founded by technical entrepreneurs from IIT Kharagpur in 1985, Signotron started with the design and manufacturing of products for Industrial Control and Pollution Control. Gradually, its focus shifted to Power Electronics, Embedded Electronics and Renewable Energy-oriented products.


  • An ISO 9001:2015 certified company.
  • Equipped with a manufacturing facility of 50,000 sq. ft located at the heart of the Salt Lake Electronics Complex, Kolkata, with more than hundreds of thousands of products in the rolling stock of Indian railways.
  • A company with 200+ employees - including 70+ graduate and post-graduate engineers, diploma-holding engineers, and technicians.
  • Globally Rated and Assessed by

Technology Innovations Through The Years (1985 - Present)


Public Address and Passenger Information System (PAPIS) and End of Train Telemetry System (EOTT)


Underslung Regulated Battery Charger cum Emergency Battery chargers for all types of LHB coaches

SMPS based power supply panel for S & T

12 kW Battery charger for Electric Loco with IGBT based front end


Underslung regulated battery chargers for all types of LHB coaches

Compact Emergency Inverter for HVAC systems for Metro Railways


Active Harmonic filters in industries for improving power factor to near unity and reduction of current harmonics


SignoFlex EV20 SMPS for E rickshaw Battery charging

180 KVA Auxiliary Converter for electric locos


SignoFlex (HFC 6-3) Battery Charger

Turnkey solution for DC systems in power utility


Solar Power Plant designing & installation


Emergency Inverter for HVAC systems for Metro Railways


25 KVA Inverter for SGAC coaches of Indian Railways

Output paralleling of grid-interactive 3 phase solar inverters


Web-based remote monitoring and control (SCADA) for solar inverters


Grid-tied Solar Inverter up to 100 KW rating introduced

Static VAR compensator for Power Factor improvement, introduced

IGBT based Battery Charge / Discharge panel with active PFC up to 70 KW


28 KW naturally-cooled Battery Charger with active P.F.C. for SGAC coaches of Indian Railways

Supplied more than 1000 units to Indian Railways to date


Thyristor based Battery Charger with regenerative Discharging for VRLA batteries up to 70 KW


Commencement of Bulk Production of 3 phase Compact drives. Now full diesel fleet of Indian Railways has been installed with such compact drives. Total field population around 14000 as of date


Field trials of small AC Motors with Built-in Inverters by Indian Railways for 100% replacement of existing small DC Motors


Prototype unit for 3 phase Compact drive for Pump and Blower Motors for Diesel Locomotives in place of DC Motors


Inverters 0.5 KVA to 5 KVA for Pantry Car applications

5 KW DC-DC Converters for Hotel load applications of Diesel Locomotives for Sri Lanka Railways


Diversified our scope to Power Electronics products in Indian Railways' Rolling Stock

MOSFET based Voltage Regulators for Motor Generator Sets of DC EMUs, in Indian Railways

Developed energy-efficient electronic lamp ballast for Railway Coaches

DC-DC Converter for Head Light Application in Indian Railways in place of Rheostat controlled headlights


The company's major thrust had been in manufacturing specialized Industrial Control products for Burner and Pollution Control- UV Flame Detector and Amplifier and a Microprocessor-based Back Feed Sequence Controller. Having more than 10000 installations in India and abroad, the above products were supplied in Steel and Cement Plants, Oil refineries and Chemical Industries

Integrity is the bedrock on which an organisation should
be structured.

Managing Director

Partha Sarathi Biswas

Founder and CEO, Signotron | PG Electronics and Communication Engineering, IISc Bangalore | B.Tech, IIT Kharagpur

After graduating from two of India's top engineering institutions, Mr Biswas worked in a public-sector engineering company in his early career. However, a strong urge to create world-class products that are proudly made in India led him to leave his corporate career. Mr Biswas founded Signotron with four other IIT alumni in 1985. Always an engineer first, it has been his continuous drive to establish the company as an institution fueled by the drive to provide resource-optimized, research-driven, technology-enabled power electronics solutions that has led Signotron to become the industry pioneer that it is today.

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Signotron Tower Plot J1-6, Block - EP, Sector - V, Salt Lake Electronics Complex, Kolkata - 700 091




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