Fairford Electronics Ltd

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Fairford Electronics Ltd
Limited Company
Founded 1979
Founder Ray Bristow & Ray Barrington
Headquarters Bristow House, Gillard Way,
Lee Mill Industrial Estate, Ivybridge, Devon
United Kingdom
Number of locations
Products Energy Saving Devices
Motor Controllers
Number of employees
Website www.fairford.com

Fairford Electronics Ltd is a UK-based motor control innovator; designer and manufacturer, and works in industrial and commercial markets worldwide.[1]

Company history[edit]

In the mid-1970s, Frank Nola of NASA invented an energy saving algorithm for single phase induction motors. Many commercial manufacturers tried to adapt this technology for three phase induction motors but failed.

In 1979 Fairford was founded by Ray Bristow and Ray Barrington. In 1982, Fairford became the first company in the world to design and produce a fully digital three phase Motor Controller with automatic Energy Optimising - the Fairford EO System was granted patents in the USA, Japan, Australia and Europe.[2]

Soft Start Technology[edit]

The soft starter market was established in the early 1980s. It developed from work done by Frank Nola of NASA to optimise the energy input to lightly loaded induction motors.

It was developed to respond to a need to overcome the limitations of the electromechanical systems. Soft Starters use Thyristors as the control elements and serves to vary the torque generated by the motor during the start in during the running stage.

Approximately only 4% of the world’s induction motors are controlled by variable speed drives. The vast majority of motors operate at a fixed speed and have little need for continuous speed variation. The persistent problem of excess torque at motor start-up using DOL and Star/Delta starting methods can be relieved by the use of soft starters.

By pulsing a thyristor, it switches from ‘off’ to ‘on’ until the current stops flowing though it - which occurs every half cycle in an AC. supply.

By controlling the switch-on point of a thyristor relative to the voltage zero crossing in each half wave of an alternating current, it is possible to regulate the energy passing through the device. The closer the turn-on point is to the voltage zero crossing point, the longer the energy is allowed to flow during the half-cycle.

Conversely, delaying the turn-on point reduces the time for the energy to flow. Putting two thyristors back-to-back (or anti-parallel) in each of the phase connections to a motor, and by precisely controlling their turn-on points, an electronic Soft Starter continuously adjusts the passage of energy from the supply so that it is just sufficient for the motor to perform satisfactorily.

The benefits of using soft starters are:

  • Reduced mechanical strain on gears and pulleys.
  • Reduced break-downs.
  • Reduced spikes in electrical demand during motor starts.
  • Some Soft Starters provide energy saving in certain applications.


  1. ^ "Fairford Electronics | Innovation in Motor Controllers". Fairford.com. Retrieved 2012-09-03. 
  2. ^ "Ray Bristow, `father of the soft-start`, dies at 79". Drives & Controls (Drives.co.uk). Retrieved 2012-09-03. 

External links[edit]