TR-100

TR-100 adjustable transformer in aircraft AC systems

The TR-100 is an aircraft adjustable step transformer used in onboard AC electrical systems where controlled low-voltage output is required. The unit operates from the aircraft 115 V, 400 Hz AC network and provides stepwise voltage regulation for connected equipment. It is used in power distribution, regulation and auxiliary supply circuits of airplanes and helicopters. In service, the TR-100 is treated as a compact aviation transformer for precise voltage adjustment rather than a general-purpose industrial transformer.

Stepwise voltage regulation function of TR-100

The main function of the TR-100 is to provide discrete output voltage levels through predefined steps. This allows the aircraft electrical system to supply sensitive equipment with the required voltage value instead of a fixed unregulated output. The transformer can be used in circuits where small voltage changes affect correct operation of regulators, control devices or measuring equipment. Stable input voltage and correct switching between steps are important for reliable operation of the connected circuit.

TR-100 in regulator and control circuits

On aircraft, the TR-100 may be used in voltage regulation and generator-related control circuits. One of its typical roles is operation with carbon current regulators, including units such as RUG-82, where adjusted voltage is needed for proper regulation of the onboard electrical system. In such circuits, the transformer is a small but important part of the control chain. If the output step is incorrect or the transformer winding is damaged, the connected regulation equipment may operate inaccurately.

Aircraft application of TR-100

The TR-100 is used in aircraft and helicopter onboard power systems of Soviet and Russian design. It is commonly associated with Mi-8 / Mi-17 family helicopters, where it is used in voltage regulation and aircraft equipment power circuits. It is also mentioned for Mi-26 heavy helicopters, where it works within the 115 V / 400 Hz AC distribution system. Depending on configuration, the transformer may also be found on An-24, An-26, An-30 and Il-76 aircraft in regulation, automation or signal circuits.

TR-100 and TR-100/2 modification

The TR-100 family includes related versions such as TR-100/2 and TR-100D. The TR-100/2 is generally associated with a dual-channel or dual 100 VA configuration, while TR-100D may refer to a remotely controlled version. These modifications should not be treated as automatically interchangeable without checking the aircraft documentation. For procurement or replacement, the exact designation, mounting version, wiring, output step requirement and aircraft system application should be confirmed.

Construction and operating conditions of TR-100

The TR-100 is designed for continuous operation in aircraft electrical systems. It is built for 400 Hz AC power, which allows compact size and suitable performance for aviation use. The unit must withstand vibration, temperature variation and long-term operation in onboard equipment areas. During inspection, attention should be paid to winding continuity, insulation resistance, output voltage steps, terminal or connector condition, housing integrity and signs of overheating.

Supply and inspection of TR-100

For procurement, the transformer should be specified as TR-100 / ТР-100, with the required modification stated if applicable. The unit may be supplied new, from storage, repaired or serviceable depending on availability. For aircraft use, product passport, operational documentation, test records or quality documents should be confirmed where required. Before installation, the transformer should be checked electrically under the required step settings and matched with the aircraft wiring documentation.

Product Type: Aircraft adjustable step transformer
Designation: TR-100
Alternative Designation: ТР-100
Function: Stepwise regulation of AC voltage
Application / Where Used: Aircraft onboard power supply and regulation systems
System / Installation Area: AC electrical distribution, voltage regulation, automation and signal circuits depending on aircraft configuration
Nominal Power: 100 VA
Supply Voltage: 115 V +5 / −7 V
Operating Frequency: 400 ±20 Hz
Output Voltage Steps: 0; 2.7; 3.0; 3.3; 3.5; 3.8; 4.1; 4.4; 5.0; 5.5 V ±10%
Load Current: Not more than 16.7 A
Current Consumption: Not more than 1.1 A
Operating Mode: Continuous
Associated Equipment: Carbon current regulators such as RUG-82 and other compatible regulation / control equipment depending on aircraft system
Compatible Aircraft / Equipment: Mi-8, Mi-17, Mi-26, An-24, An-26, An-30, Il-76 and other aircraft depending on electrical-system configuration
Related Modifications: TR-100/2 dual 100 VA version; TR-100D remote-control version
Weight: Not more than 1.1 kg
Precious Metals Content: Silver approx. 2.21 g
Non-Ferrous Metals Content: Aluminum approx. 0.12 kg; copper approx. 0.22 kg
Condition: New / from storage / repaired / serviceable depending on availability
Inspection / Testing: Winding continuity check, insulation resistance check, output voltage step verification, current consumption check, housing and terminal inspection
Technical Documentation: Product passport and operational documentation as applicable

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