Wallis Hivolt

Dominion Way, Worthing – 15th February, 1989.

The party, comprising seventeen members, was welcomed to the Wallis Hivolt company by Principal Sales Engineer Mr. Richard May.
We were informed that the company employs between 140 and 150 personnel including engineering and support staff. All design and development work being undertaken on site.

Mr. May then proceeded to give a most interesting talk on the company products and their use and application.
It was initially explained that all their products were units which produced high d.c. voltages in the range of about 5 KV to 500 KV, all such power supplies being of low current output but with extremely stable voltages. All units having very low ripple levels and very constant voltage outputs.
To demonstrate the type of output produced a 30 KV d.c. spark gap was energised, the gap being powered by a 30 KV generator supplied from a normal 240 V.a.c. 50 Hz supply. The high voltage being provided by means of radio frequency transformer and d.c. voltage multiplier.

The company products were very specialised being high voltage d.c. power units only, manufactured for incorporation into various equipment produced by other original equipment manufacturers. Since many of the Wallis Hivolt units are fitted into equipment which must survive in extremely harsh environments (e.g. military equipment) much of the units are ruggidised to a very high standard.
Typically power supplies were provided for the following types of equipment :

High stability Visual display units as used with computers, military aircraft cockpit displays, flight simulators etc.
Electron microscope supplies.
Photomultiplier supplies.
Ion Implantation equipment.
Electron beam welding equipment.
Insulation testing.
Colour Printing.
Photo Typesetting.
Travelling wave tubes,
X Ray generators.
Mass Spectrometers.

The units manufactured were based on the use of d.c. voltage multipliers mostly of the Cockcroft-Walton type (a capacitor/rectifier stack system) or by the use of radio frequency transformers provided a high voltage rectified to provide a d.c. output. Much of the equipment was a combination of these two principles. The initial power supply for the high voltage units could be either normal a.c. mains supply at local voltage and frequency, or from d.c. battery, especially for portable type items.

Following the product briefing (plus a welcome coffee) the manufacturing area was visited. The manufacturing process is of a batch production nature and comprised coil winding, manual printed circuit board assembly, unit assembly and unit wiring. All cabinets and sheet metal work is subcontracted and all electronic components bought in.
Sizable quality assurance and test departments were much in evidence.
The visit lasted about two hours and proved to be both interesting and informative.
Report by E.W. Roubaud,