Advance Product Services Ltd. (APS)
The DC power supply repair specialists.
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About Us

APS Premises

Incorporated in 2002, Advance Product Services Ltd (APS) was set up to offer a dedicated support service for AC-DC power supplies and rectifiers. We work with telecoms, transport, utility, energy, aerospace, industrial and defence companies who have a problem with critical equipment going off line due to component failure or product obsolescence.

Specialising in DC power supply repair, APS is run by ex-Farnell (subsequently Advance Power & APC) design engineers with over 100 years combined experience in linear and switch mode psu technology.

As part of the original psu design team at Farnell in the 1960's to late 1990's, we were instrumental in the design and manufacture of what are reputed to be some of the most reliable power supplies in the world. Importantly, we still have legitimate access to much of the original Farnell design documentation including test procedures, schematics and parts lists.

We carry a large OEM spares inventory, as used in the original products; ensuring repair work can be carried out without compromising approvals or product quality. Should an original part be obsolete, we have the knowledge and experience to readily source a suitable equivalent - as you would expect from design engineers.

Safety is of paramount importance to us. We have full PAT and flash test facilities and all units are subjected to a comprehensive insulation and isolation test, pre and post repair.

At the request of our customers, we now support psu's, rectifiers and static switches from most of the mainstream manufacturers including TDK Lambda, Delta, Emerson, Dale Erskine, Siemens, Motorola, Eltek, Weir, Harmer and Simmons, Ferranti, Artesyn, Uniphase, XP, Astec, Coutant, Power One, Kingshill, Meanwell, Murata, Traco Power, ABB, Omron, Cosel, Vicor, and many others. Our repair rates are usually substantially less than OEM and the quality of our workmanship is unsurpassed. That's why we are entirely confident to offer a full 12 month warranty on every repair.

So whether it be a power supply repair, refurbishment or (where that is not possible) a custom designed replacement for an obsolete product, we can help. We supply off the shelf replacements for virtually all the Farnell / Advance range and can design and build custom psu's to your specifications. We specialise in low—mid volume so even a one off is usually economic.

We are fully accredited to IS09001 & ISO14001 and have won numerous customer satisfaction awards . You get integrity, consistency and traceability every time.

Company History



Cyril Stapleton started making components for the infant radio industry - including transformers, "cats whiskers" and potentiometers from a small converted chicken shed in Walthamstow, North London.


The Company was called Advance Components and up to the beginning of the Second World War, manufactured components and simple instruments for the radio industry later moving to newer premises in North London.


A.C. Farnell was formed to sell radio components. Its first premises were in Central Street, Leeds, UK.


The majority of output from Advance Components was switched to components and test instruments for the war effort. These products included the Constant Voltage Transformer (CVT), the forerunner of the future growth of the power supply elements of the company's business.


A subsidiary of A.C. Farnell, named Farnell Instruments Limited was founded. Originally it was a northern sales agent for southern based Test and Measurement equipment manufacturers.


The Boston Spa based Royal Ordnance Factory operations were running down and Farnell took the opportunity to employ a team from that factory to start manufacturing and repairing test meters. Premises were leased in Wetherby on the York Road industrial estate. These consisted of ex W.D. Nissen huts. A small team, initially of 7 people, moved in the following year.

Following the war, Advance Components continued to grow and prosper and moved to larger premises in Hainault, Essex. At the same time, the first of a new range of products was developed, including a range of attenuators and higher powered CVT's.


The original Farnell Wetherby factory was extended by the addition of a new Marley building.

Advance Components changed its name to Advance Electronics Limited, to reflect the changes that had occurred in the former radio industry. The company also became publicly listed in the London Stock Exchange.


Signals generators, oscilloscopes and general purposes test instruments formed the bulk of the Advance's products while the production of CVT and "strip" products, including a range of linear power supplies, continued. The plant at Hainault became too small and a greenfield site was sought for a dedicated power supply factory.


Land purchased at Bishop's Stortford for £50,000. But it was not until 1968 that the factory was built.


New purpose built premises on Sandbeck Way, Wetherby were completed and occupied by Farnell Instruments. By now the workforce had grown to around 40 people.


Adjacent land purchased and further factory extensions undertaken by Farnell Instruments. The Sandbeck Way site was further extended in 1974 and 1985.


The Farnell Group became a public limited company when shares were offered on the London Stock Exchange.


In 1968 the entire product line at Advance Electronics was transferred from Hainault to a new, custom-built factory in Bishop's Stortford, Hertfordshire. At the same time, the Research and Development team was assigned to develop a series of switching power supplies using a new technique being developed in America.


The first UK designed switch-mode power supply was launched by Advance. This was the MG5-20, which delivered 5V at 20A from a 240Vac input. The unit was packaged in one eighth the size of conventional linear units. The MG was ranged to include other output voltage values, which all offered the same superior power to weight/size ratio. A series of other output power models was developed that gave Advance a range of products from 25 to 500 Watts output power.


The US company, Gould Inc., was expanding into mainstream electronics and acquired Advance renaming the company Gould Advance. Initially, there were few changes and the two operations were encouraged to develop and manufacture power supply and instrumentation products at their respective locations. Bishop's Stortford continued developing switch-mode power supplies and multi-output units.



BBH Coil and Transformer Company of Bishop Auckland acquired by Farnell Instruments Limited.



Farnell International Instruments Limited formed to handle import of traded products and export of Farnell's manufactured products.



Farnell International Instruments took a 60% holding of an Italian company Farnell Italia to market its products in Italy.


Another factory built on Sandbeck Way for Farnell Instruments - named Jubilee House to commemorate the first 25 years.

The Hiflex modular system was announced and launched by Gould Advance. The low cost open frame Simflex and Econoflex were introduced, together with other signal and multi-output products.

Farnell Instruments built a new factory on a 6 acre site at Boroughbridge, N.Yorkshire.



Printed Circuit manufacturer Kelan Engineering acquired by Farnell.


Gould Advance sold the Bishop's Stortford operation to the management and was renamed Advance Power Supplies. At this time, the company successfully launched the Powerflex and A1500 Powermag and opened a USA based subsidiary and a further one in Frankfurt, West Germany.



Advance Power Supplies purchased Bryans Southern Instruments located in Mitcham. This acquisition operated as a standalone instrument business and was renamed Advance Bryans Instruments Limited. In November of the same year, Low & Bonar PLC acquired the two Advance operations, together with their overseas subsidiaries. They became part of the new Low & Bonar Electronics Division. The power supply operation and two USA based subsidiaries, Powertec and SCI, were bonded into the Bonar Power Supplies Group which operated as a world-wide developer, manufacturer and marketer of switch-mode power supplies. In December, the company was renamed Bonar Advance Limited.


In July 1988, the Farnell Group acquired, from the Low & Bonar company, Advance Power Supplies and its subsidiaries at Bishop's Stortford and Wallis Hivolt at Worthing. The company continued to run as an autonomous unit within the Manufacturing Division of the Farnell Group and the name was changed back to Advance Power Supplies Limited in September.



The Farnell Group acquired Wayne Kerr plc. and its subsidiaries, a well-known manufacturer of Automatic Test Equipment and measurement bridges.


The Sales and marketing functions of Farnell Instruments Limited and Advance Power Supplies Limited merged into one operation under the name Farnell Advance Power whilst the manufacturing section retained the name Advance Power Supplies Limited.



Wayne Kerr Elektronikai KFT was founded in Budapest, Hungary.


The Farnell Group acquired Cayson Engineering at Watford. At the time Cayson was one of Farnell's largest customers for telecommunication power supplies.



Farnell Cayson relocated from Watford to the Farnell Advance factory at Bishop's Stortford when the lease of their premises at Watford expired. This brought the production of large, high powered transformers and power supplies under the Advance Power Supplies product system.


The manufacturing division is restructured into three companies: Farnell Power Limited, Farnell Instruments Limited, Farnell Technology Limited. The name Advance Power Supplies Limited ceased to exist. The name Farnell Cayson continued as a separate entity. At the same time administration for both companies was moved to Wetherby.


Farnell Instruments relocated from Wetherby to Bognor Regis.


31st March: Farnell Electronics PLC announced that it had sold the whole of its manufacturing capability to the Holding Company Savidon Limited, funded by the venture capital of CINVen.

Savidon announced that the manufacturing group would remain as a total entity with no change in management. The name of the group, whilst closely linked with Farnell in the early stages, would be changed eventually to the new name Advance International Group. In June 1995 the company registered a change of name to Advance International Group Limited.



The remaining division of Farnell Electronics PLC continue as Farnell Electronics Components (FEC), concentrating solely on component distribution and move to offices in Armley, Leeds. A few months later FEC acquires Combined Precision Components (CPC).

The Bishop's Stortford site was renamed Advance Cayson. At the end of the year, the company name was changed to Advance Power Systems to reflect the type of products manufactured at the site.



Advance International Group Limited founded Advance France in Paris.

FEC buy the Premier Industrial Corporation, a leading US distributor, and in doing so change its name to Premier Farnell.


Savidon sell the Wetherby site to GSM metalwork and the Northern based Advance Power Systems staff move to join their colleagues at the Boroughbridge site.



A cross site management team was implemented at Bishop's Stortford and Boroughbridge. This merged the operations of two similar manufacturing sites and increased awareness of the company in the market place. The company name across both sites became Advance Power to reflect the increased links between the two sites while also reducing the similarities in name with a competing company in North America.

Advance International Group acquired a 60% share in the California based Tektris Electro Corporation - now Advance Tektris.



Sale of Rendar Limited of Bognor Regis to Schurter Holding AG of Lucerne, Switzerland.
Advance Power opens its new office in Shanghai, China.
Advance Power acquires the systems product line of Pyramid Power Systems, an operating division of Pyramid Industries.


Advance International Group (AIG) acquire Horizon power systems business & Dallas manufacturing facility of Yuasa Energy Products Group, an operating division of Yuasa Inc.


Sale of BBH Windings of Bishop Auckland to Weyrad Ltd of Weymouth, UK.

New Advance Power regional sales office opened in Leesburg, Virginia, USA.


Sale of Advance Power to APC (American Power Conversion) to complement their range of UPS’s (uninterruptible power supplies). The newly formed subsidiary is renamed APC DC Network Solutions UK Ltd.


APC wind down the DC Network Solutions UK Ltd power supply design and manufacturing operations at Boroughbridge and Bishop’s Stortford. Over 700 staff are eventually made redundant and both sites are closed. APC retain a small DC Networks sales presence in the UK.

A group of design engineers from the Boroughbridge site set up a new company called Advance Product Services Ltd (APS), supporting the entire Farnell and Advance product range with repairs, replacements and technical support.


French group Schneider Electric buy American Power Conversion for $6.1bn.

Advance Product Services Ltd launch range of fit, form and function replacement power supplies for the obsolete Advance and Farnell units including the MG5-20 (the first UK designed switch mode power supply from 1970!).



Advance Product Services Ltd move to larger premises on Harrogate Business Park, N. Yorkshire and see increase in demand for high quality custom power supply designs.