Fairfild

Based in Milano, Italy, Fairfild operates in the field of power resistor production, specialising in products for the traction market. Since 1977, we have manufactured a large range of standard resistors for many different applications. Fairfild is able to meet many requirements, fulfilling the needs of its customers, as well as relevant international standards.

Resistors for severe environments and outdoor mounting

Our resistors are designed to withstand severe environmental conditions and are suitable for outdoor mounting. The main construction features include high insulation and high life expectancy, while most can be made in special versions, such as non-inductive, special insulation, special terminals or cables and thermal switch.

The constant research and the implementation of operative procedures and instructions on our production technology allow us to apply the concept of "repeatability" to processes that are typically characterised by a high manual component.

Our resistors are used in the following fields:

• Railway traction
• Energy conversion
• Industrial automation
• Services for the industry
• Heating

Replacement parts for old resistors

Customers that use Fairfild’s innovative solutions, as well as its replacement of parts of old resistors, are more than satisfied. High quality and efficient production processes are fundamental to meet our customers’ expectations, as well as precise punctuality, together with high skills and vast experience, making Fairfild a reliable partner.

Resistors for electrical circuits

From a functional point of view, our resistors can be placed into electrical circuits that include:

• Braking resistors
• Grounding resistors
• Filtering resistors
• Motor control resistors
• Charge / discharge capacitors

Resistor applications

Our products’ application area is power electronics with the function, amongst others, to manage and control the electric power flow, supplying tension and currents in an optimal way to load devices such as electric motors.

A few examples include devices and circuits that convert electric voltages from alternated to continuous mode (AC-DC) and vice versa (DC-AC), or to the level control of the DC voltage, to the frequency variation, to the supply of the DC motors, to the speed control of an AC motor or to the torque control of a DC motor.

The typical applications of our resistors include:

• Discharge
• Charging and discharging
• Power
• Precharge
• Over voltage protection
• Resistor for short circuit protection
• Soft crowbar
• High voltage filter
• RC filter
• HVAC filter resistor
• Damping resistor

Power resistors for electric circuits

Together with the diode valves rectifiers, SCR, IT GIVES, TRIAC, IGBT, GTO, transistors and capacitors, there are power resistors, which can be found in nearly all electric circuits. Resistances are not undifferentiated; the most suitable resistance has to be selected based on the application it will be involved in.

The main adopted technologies include:

• Tape / wire wound coated by vitreous enamel or cement on ceramic support
• Hermetically sealed stainless-steel tubes
• Hermetically sealed aluminium cases with or without heat sink
• Cooled liquid
• Iron cases (not hermetically sealed)
• Metal boxes
• Uncoated wire wound
• Edge wound
• Oxidised wires
• Grids or plates