History:

  The main Revel Railway Workshops were founded on November 27, 1870.

  On the general meeting on August 4, 1941 the decision was made to create the defence fund to help the Soviet motherland to struggle against fascism.

  After factory restoration in 1946, the level of manufacture reaches the pre-war level.

  In 1957 due to specialization change of the factory, it was renamed into Carriage-repair Factory.

  In 1958 because of decision made to specialize the factory on mercury converters and power transformers for electric locomotives of alternating current, the factory receives the new name - Tallinn Factory of Mercury Rectifiers after M. I. Kalinin.

  In 1958 the release of mercury and semi-conductor rectifiers was began and two years later the first transfomer for electric locomotive by capacity 5600kWA was issued.

  On December 1961 the Special Design Bureau (SKB) was organized. Its primary duty were the development and production of semi-conductor devices.

  In 1962 the first gate VÊ-200 on floatable technology was manufactured, ànd 4 years later the first serial gate VKD-200 on diffusive technology was made.

  The first converting installation on semiconductors was made in January, 1962

  From July 1964 the ignitron IVU-500/5 production has began (the lead-ins were protected by ceramic barrier).

  In 1965-1966 the decision was made to organize manufacture of semi-conductor gates and the release of first serial gate VKD-200, as well as to develop and hand over into a batch production the converter installations of high power based on mercury rectifiers.

  In 1967 the rectifying invertor converters VIPE-1 type for railway traction substations (power 8 MWt) were released.

  The manufacture of first frequency gates VCH-100, VCH-160, VCH-200 and frequency thyrirstors TCH-16, TCH-40, TCH-63, TCH-100 was began in November 1968.

  In 1968 the production of thyristor frequency converters TPCH-1 type (with air cooling, 630 kWt, 1000 Hz) for electrothermics is started.

  In 1969 ãîäà the development and production of thyristor frequency converters (TPCH type with water cooling, power 800-2400 kWt for electrothermics) was began.

  In 1970 – 1972 the production of IInd generation frequency converters TPCH type with water cooling (based on press-pack thyristors for electrothermics) was mastered.

  In 1972-1974 the production of IInd generation rectifying invertor converters of VIPE-2 type for railway traction substations (on power thyristors of clamping type by capacity 8 MWt) was developed.

  In 1974 - 1975 the production of frequency pulse thyristors with regenerative management of TCHI-100 and series of fast thyrstors TBZ-160, TBZ-200, TBZ-250, TBZ-320, ÒÁZ-400 was began.

  In 1975-1977 the manufacture of uninterrrupted supply units of ABP-1 type based on voltage inventor and interrruption for chemical manufactures was started.

  In 1978-1980 the factory conducted: the production of III generation converters on fast thyristors TBI type (power 100-3200kWt, frequency 500-10000 Hz); the production of power high-voltage converters for synchronous and asynchronous electric drive (power up to 5000kWt, 6 kV (asynchronous) and 15kV (synchronous); as well as the manufacture of IST type rectifiers and the equipment of scientific centers by them.

  In 1981 the unified fast thyristors and diodes series with competitive technical and economic parameters on diffusive technology production was developed and mastered.

  In 1985-1990 the new generation of converters for asynchronous high-voltage electric drive was worked out (capacity up to 5000kWt, on press-pack thyristors and thermal power stations equipment.

  In 1987 the production of IIIrd generation of power electronic devices of unified series was initiated.

  In 1991 -1993 the production of unified series V-MPPD rectifiers for main diesel locomotives on a current up to 8000À was began.

  The series of press-pack devices (Ò243-800, Ò343-630, Ò153-1600, Ò253-1250, Ò353-1000) with competitive technical and economic parameters was developed and handed over within the framework of joint project Estel-ABB in November 1996.

  Since 1997-1998 the power rectifier for titanium melting in arc furnaces (output current 16000À) have been developed and manufactured.

  In 1999-2000 the IVth generation of frequency converters TPCH was developed (based on new element and constructive base (power 100-800kWt, frequency 500-10000 Hz), as well as power rectifier for titanium melting in arc furnaces (output current 35000À).