Custom Toroidal Transformers
Toroidal transformers deliver high efficiency, very low stray magnetic field and low audible noise in a compact, cool-running package. P&A International engineers, prototypes and delivers custom toroidal transformers — power, audio, medical and isolation types, a few VA to multi-kVA, 50/60 Hz — built exactly to your voltage, regulation, isolation and mechanical requirement.
As an engineering-led contract manufacturer founded as an engineering consultancy, we assign one dedicated engineer to your project from design review to qualified samples in 10–15 working days, then scale into volume through our vetted partner-factory network, where every supplier is ISO 9000 certified or better.Request a quote ›
consultancy + manufacture
per project, end-to-end
qualified samples with test data
every supplier certified or better
one-off to high volume
Why choose PA toroidal transformers
High efficiency
A continuous toroidal core gives low losses and high efficiency, with cool, quiet running.
Low stray field & noise
Symmetrical winding cuts radiated field and audible hum — ideal for audio, medical and instrumentation.
Safe isolation
Reinforced or screened construction with creepage and clearance to IEC 61558 / EN 61558, CE and UL as specified.
Built to your spec
Custom voltages, taps, multiple windings, mounting and potting — designed and DFM-reviewed for your product.
Engineering capability
- Magnetic design & simulation — turns ratio, regulation, flux density, temperature rise and tolerances
- Core grade & winding strategy for low loss, low stray field and low audible noise
- Electrostatic screens and multi-winding / multi-output designs
- Safety construction — reinforced or screened isolation to IEC 61558 and EN 61558
- Encapsulation, dip-coating and mounting (centre-bolt, base, flying-lead) to your envelope
- DFM review to hit target cost while preserving performance
- Qualified samples with full test data before any volume tooling
- One dedicated engineer owns the project end-to-end
At a glance
| Type | Toroidal — power / audio / medical / isolation |
| Power | A few VA – multi-kVA |
| Frequency | 50 / 60 Hz line frequency |
| Windings | Single & multi-output, taps, screens |
| Isolation | To CE / UL / IEC 61558; reinforced available |
| Mounting | Centre-bolt, base plate, flying-lead, potted |
| Prototype | 10–15 working days to qualified samples |
| Quality | Every supplier in our network is ISO 9000 certified or better |
Why engineers & buyers choose PA
For design engineers
A true design partner — one dedicated engineer, full magnetic simulation and DFM support, rapid samples, and toroidals optimised for efficiency, regulation, stray field and audible noise. We design to your voltage, isolation and mechanical envelope — not just catalogue parts.
For purchasing
Low-risk scalability — predictable 10–15-day prototypes, flexible MOQ from one-off to production, target-cost DFM, a single point of contact, and a vetted ISO 9000+ partner network managed end-to-end by P&A. No hand-offs, no surprises.
3 easy steps to get started
Send us your spec
Send your drawing or spec sheet. One dedicated engineer reviews it and confirms the technical details with you.
Proposed design & quote
You receive a proposed design and indicative pricing — typically within 48 hours — to review and refine together.
Samples & production
Qualified samples with full test data in 10–15 working days; on approval we scale into volume through our partner network.
Applications
Hi-fi & professional audio · medical and laboratory instrumentation · lighting and LED · industrial control & automation · test & measurement · renewable-energy and general power conversion.
Explore related types: low-frequency & power transformers, three-phase and encapsulated transformers; for switch-mode designs see high-frequency & switch-mode magnetics.
Choosing the right toroidal transformer
A few decisions shape every toroidal design — sharing this detail lets us quote and prototype faster:
| Voltage & regulation | Primary/secondary voltages, taps and the load regulation you need set the turns ratio, copper size and core. Tighter regulation means more copper and a larger toroid. |
| Stray field & noise | Where low radiated field and low audible hum matter (audio, medical, metrology), winding symmetry, balancing and a magnetic screen can be designed in. |
| Temperature rise | Core and copper loss drive temperature rise and insulation class; we select core size, wire gauge and potting to stay inside your thermal limit. |
| Isolation & safety | Creepage and clearance, the insulation system (reinforced or screened) and compliance to IEC 61558 / EN 61558, CE and UL are designed in from the start. |
| Mounting | Centre-bolt, base plate, flying-lead or fully potted — with terminations and dimensions to suit your enclosure and assembly. |
What to send us for a fast, accurate quote
The more of this you can share, the quicker we can return a proposed design and price:
- Primary and secondary voltages, VA rating and number of outputs
- Load regulation, taps and any electrostatic screen requirement
- Stray-field / audible-noise constraints (audio, medical, metrology)
- Isolation and safety requirements, and target standards
- Mechanical envelope — diameter, height, mounting, terminations — and thermal limits
- Target cost and annual volume or call-off pattern
- Any reference design, competitor part number or physical sample
Working from a competitor part or a sample is fine — our engineer will reverse-engineer it or design a drop-in equivalent to your specification.
📄 Download the toroidal transformer RFQ checklist & selection quick reference (PDF)
Get a quote
Send your voltages, VA rating, spec sheet or sample and one dedicated engineer will reply — typically within 48 hours — with a proposed design and indicative pricing. No project too big or too small.
One dedicated engineer reviews every enquiry and replies with a proposed design and indicative pricing. Your details are used only to respond to your enquiry. Prefer email? support@pa-international.com.au