What Amethyst Designs does

Amethyst Designs Limited is a UK-based private designer and manufacturer of custom transformers and wound components, founded in 1982 by John Anderson and Pat Sheridan and headquartered in Bar Hill, Cambridge. The company produces transformers and inductors across a broad power range (1VA to 300KVA), spanning toroidal, ferrite core, laminated, bobbin and high-frequency designs, alongside specialised aluminium foil inductors and self-supporting coils. Manufacturing is supported by in-house vacuum impregnation, cast resin encapsulation, Litz wire winding, and CAD-based production. The firm has built a library of more than 2,000 original designs and maintains JOSCAR registration alongside ISO 9001:2015 and ISO 14001:2015 certifications, qualifying it for defence, aerospace, and security supply chains.

The company's revenue model is built on B2B direct sales: customers submit detailed technical specifications (voltage, frequency, VA rating, load type, duty cycle) via a structured quote request, and Amethyst produces one-off, small-batch, or volume orders to those specifications. Pricing is quote-based, with quotations valid for 30 days, payment due on order acceptance or net 30, and online payment (via Stripe) available for UK customers. Revenue streams include custom transformer hardware sales and design/engineering consultancy services. The customer base spans industrial electronics, defence and aerospace, specialist high-voltage applications (gas, lighting, powder coating) and electronics manufacturing services.

Between 2021 and 2025 Amethyst executed a systematic roll-up, acquiring Cambridge Transformers, Aluminium Inductors, Electro Inductors, BC Electrical Techniques and Repanco Bartlett, consolidating five acquired facilities into the Bar Hill site and bringing former MDs and specialist engineers in-house. The firm now operates as a single-site specialty manufacturer with an expanded catalogue that includes the Tranilamp control transformer range and several retained legacy sub-brands, while maintaining bespoke design as its core differentiator against volume-oriented competitors.

Name

Amethyst Designs

Legal name

Amethyst Designs Limited

Website

https://amethyst-designs.co.uk

Company type

Private

Founded year

1982

Operating status

Operating

Headcount range

11–50 employees

Short description

Amethyst Designs is a UK-based designer and manufacturer of custom transformers and wound components (1VA to 300KVA), serving industrial electronics, defence, aerospace and specialist high-voltage customers with bespoke, small-batch and volume production from a single facility in Bar Hill, Cambridge.

Ownership category

akta.pro rank

Product category

Transformer Manufacturing

NAICS

Power, Distribution, and Specialty Transformer Manufacturing (335311)

SIC

Power, Distribution & Specialty Transformers (3612), Electronic Coils, Transformers & Other Inductors (3677)

akta.pro primary industry

Transformers (Power, Distribution, Instrument, Specialty) (IMAGAAAA)

Keywords

• Custom transformer manufacturing
• Wound components design
• Toroidal transformers
• Ferrite core transformers
• Power inductors

Headquarters

HQ city

Cambridge

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Operations, Supply Chain, Infrastructure, Marketing or Sales, Technology or R&D

Revenue model

1. Custom Transformer Manufacturing: Design and manufacture of custom transformers and wound components to customer specifications. Products include toroidal transformers, ferrite core transformers, laminated transformers, bobbin transformers, aluminium inductors, and self-supporting coils. Revenue generated from one-time product sales with pricing based on custom specifications.
2. Design and Engineering Services: In-house design team provides engineering services to identify customer requirements and develop cost-effective solutions conforming to appropriate standards. Professional consultancy services performed with care and skill expected of competent consultants.

Pricing tiers

Go-to-market motion2 records

Distribution channels2 records

Marketing channels4 records

Core offering

Amethyst Designs designs and manufactures custom transformers and wound components in the UK, with power ratings ranging from 1VA to 300KVA. Product lines include toroidal transformers, ferrite core transformers, bobbin transformers, laminated transformers, aluminium foil inductors, self-supporting coils, and the Tranilamp control transformer range. The company combines volume production capability with specialization in small batch and bespoke one-off designs, supported by in-house design, vacuum impregnation, and cast resin encapsulation machinery.

Product overview

Amethyst Designs is a UK-based designer and manufacturer of transformers and wound components offering products ranging from 1VA to 300KVA. The company operates a single-site facility in Bar Hill, Cambridge and specializes in delivering custom transformer solutions alongside volume manufacturing capabilities. Their product portfolio centers on core offerings including Custom Transformers, Toroidal Transformers (standard and ferrite core), Bobbin Transformers (encapsulated and ferrite variants), Laminated Transformers, Aluminium Inductors, and Self Supporting Coils. Through strategic acquisitions, the company has expanded to include several sub-brands: Aluminium Inductors, BC Electrical Techniques, Cambridge Transformers, Electro-Inductors, Morite Windings, Repanco Bartlett, and Tranilamp Transformers. The Tranilamp acquisition added a comprehensive range of control transformers (TCX, TC, STK, TUF, TCF, TTP, TTS ranges) and auto starter transformers. The company emphasizes in-house design expertise, automated manufacturing, and specialized capabilities including vacuum impregnation and cast resin encapsulation.

Differentiator

Problem solved

Functional benefit

Brands

• Aluminium Inductors: Specialises in windings and air cored inductors using aluminium foil. Capabilities include air and iron cored inductors for power electronics, inrush limiting inductors, magnet coils, litz windings, and high power high frequency transformers.
• BC Electrical Techniques
• Cambridge Transformers
• Electro-Inductors
• Morite Windings
• Repanco Bartlett
• Tranilamp
• Zeta Windings

Products and services

• Custom Transformers Custom-designed transformers and wound components ranging from 1VA to 300KVA, including electron beam optics, high voltage trigger transformers for gas and lighting industry, and high voltage wound components for powder coating processes. Designed to customer specifications for industrial electronics, defence, aerospace, and security sectors.
• Toroidal Transformers Toroidal core transformers offering higher efficiency, smaller size, lower weight, reduced mechanical hum, and lower exterior magnetic field compared to conventional laminated transformers. Operates at required frequencies with dimensional flexibility.
• Ferrite Core Toroidal Transformers Ferrite core transformers, inductors, and ferrite coil windings designed and manufactured in-house to customer specifications, supporting foil windings, multi-strand windings, and screens. Designed for high frequency power applications up to 40kVA continuous.
• Bobbin Encapsulated Transformers Encapsulated transformers using standard enclosures or custom tooling to suit customer requirements, with UL approved materials available. Commonly used in high voltage transformer applications.
• Bobbin Ferrite Transformers Bobbin ferrite transformers for power supply and power conversion applications, typically based on RM, ETD, EF and EE type bobbins and cores, with design solutions using standard sizes or custom formers.
• Laminated Transformers Single or three phase laminated transformers with custom ferrite sheets and conductor patterns, laminated and baked to customer specifications.
• Aluminium Inductors Specializes in windings and air cored inductors using aluminium foil for high current applications (5 to 1000 Amps continuous), offering half the weight of copper with no saturation. Includes air and iron cored inductors, inrush limiting inductors, litz windings, and high power high frequency transformers.
• Self Supporting Coils Precision wound self-supporting coils for applications requiring specific shapes or small form factors. Used for radio frequency tuning, suppression, high saturation inverter chokes, pot cores, air inductors, and military or medical applications.
• Tranilamp Transformers Full range of Tranilamp control transformers including TCX (25VA to 2kVA), TC (50VA to 5kVA), STK (25 to 2kVA), TUF (10VA to 4kVA), TCF (3.6kVA to 65kVA), TTP (2kVA to 100kVA), TTS (0 to 50kVA three-phase to single-phase), and specialty transformers including ATP auto starters (10kW to 860kW).
• Design and Engineering Services In-house design team provides engineering services to identify customer requirements and develop cost-effective transformer solutions conforming to appropriate standards. Professional consultancy services performed with the care and skill expected of competent consultants.

Quantifiable outcome

• Transformers designed from 1VA to 300KVA power range
• +2 more outcomes

Segments4 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

One partnership is on record.

• TranilampcoreStrategic or Co-development PartnerAmethyst Designs acquired the Tranilamp transformer product line and now manufactures all Tranilamp Transformers. Price, delivery, product codes and terms remain unchanged. CAD files continue to be available for TC, TCX and STK ranges. Tranilamp continues to supply its other product range including indicators and lenses.

Scale indicators5 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Block Transformatoren-Elektronik: Block is a European custom transformer and power magnetics manufacturer with deep specialization in customer-specific designs (toroidal, laminated, chokes, filters). Its product breadth, design-led philosophy and SME heritage make it the closest direct peer to Amethyst's custom-transformer model.
• Noratel: Noratel is a Nordic-headquartered group of custom magnetics manufacturers producing transformers, chokes, filters and wound components for industrial and traction applications. Its multi-brand European roll-up strategy and custom-design orientation map directly onto Amethyst's approach.
• Myrra: Myrra is a long-established European designer and manufacturer of small transformers, chokes and wound components. Its emphasis on PCB-mount and custom industrial magnetics at a similar scale to Amethyst makes it a directly comparable specialty supplier.

Broad incumbents

• TDK-Lambda: TDK-Lambda is the industrial power-supply arm of TDK, with significant custom magnetics and transformer capabilities supporting industrial, medical and railway customers. It competes with Amethyst for higher-power custom transformer business while operating a much larger global footprint.
• Signal Transformer: Signal Transformer (a Bel Fuse company) manufactures a broad catalog of low-power transformers, toroidal inductors and custom magnetics for industrial and commercial applications, overlapping with Amethyst's custom toroidal and laminated transformer range.
• Hammond Manufacturing: Hammond is a Canadian manufacturer of transformers, filters and enclosures with a global industrial footprint. Its custom and catalog transformer lines overlap directly with Amethyst's portfolio while operating at significantly larger scale.
• Triad Magnetics: Triad Magnetics is a US-based broad-line manufacturer of audio, power and custom magnetics. Its custom design-and-build service and industrial transformer range directly overlap with Amethyst's custom offerings, but it operates from a much broader catalog.
• Standex Electronics: Standex Electronics designs and manufactures custom magnetics, reed switches and sensors, including custom transformers and inductors for industrial applications. It is a broad incumbent comparable to Amethyst's custom-engineering model across multiple end markets.
• Würth Elektronik eiSos: Würth Elektronik's magnetics division is a broad-line manufacturer of transformers, chokes, inductors and power magnetics. It overlaps with Amethyst across ferrite-based power magnetics and litz-wound inductors but operates at substantially greater scale across a full magnetics catalog.
• Coilcraft: Coilcraft is a major US-headquartered magnetics specialist manufacturing RF and power inductors, transformers and chokes. It competes with Amethyst in custom wound components for industrial and power-electronics customers across global markets.

Market position

Strengths5 records

Weaknesses4 records

Competitive moat4 records

Key risks6 records

Key highlights6 records

Customer concentration

• Facebookfacebook.com/Amethyst-Designs-Limited-218966254811297
• Instagraminstagram.com/amethystdesignsltd
• Xx.com/AmethystDesigns

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Subsidiaries5 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Amethyst Designs