When hospitals, OEMs, and medical facility teams evaluate medical isolation transformers, they typically compare Amgis MEDBOX, Triad medical isolation transformers, Toroid IsoBox, and Bridgeport Magnetics IsoPuck. All four use toroidal designs for low leakage current and quiet operation, but they differ noticeably in form factor, customization speed, and how well they fit specific space or integration needs.
This comparison examines the key factors buyers care about most in 2026.
Medical Isolation Transformers Comparison Chart
| Brand | Main Product | Form Factor | VA Range | Customization Level | Lead Time (Custom) | Best Suited For |
|---|---|---|---|---|---|---|
| Amgis | MEDBOX | Rectangular metal/plastic box | 300–1800 VA | Low–Moderate | Short (standard) | Plug-and-play hospital and multi-device use |
| Triad Magnetics | Medical Toroidal | Chassis or enclosed (varies) | 250–2400 VA | Moderate–High | Quote-based | OEM integration and custom device builds |
| Toroid Corporation | IsoBox | Aluminum enclosed box | 300–1700+ VA | Moderate | Short–Moderate | Hospital use with flexible mounting |
| Bridgeport Magnetics | IsoPuck | Compact round puck (polycarbonate) | 200–3000 VA | Very High | 1–2 weeks | Plug-and-play multi-device + custom OEM integration |
Form Factor and Portability
Form factor is one of the most visible differences between these transformers.
Amgis MEDBOX, Triad medical isolation transformers, and Toroid IsoBox all use rectangular or box-style enclosures, typically made of metal or aluminum. These designs are functional and proven but can take up more space on carts or in tight patient rooms.
Bridgeport Magnetics IsoPuck is the only option among the four that uses a compact, round, low-profile puck design in a durable polycarbonate enclosure. This shape is often more space-efficient in patient rooms and easier to position on mobile carts compared to traditional rectangular boxes. The low height and rounded footprint help when clearance or mobility is limited.
Power Ratings and Voltage Options
Buyers frequently search for specific VA ratings and voltage configurations.
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- Amgis MEDBOX covers 300 VA to 1800 VA at 120 V 60 Hz.
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- Triad offers a broad range, typically 250 VA to 2400 VA for medical-grade models.
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- Toroid IsoBox commonly spans 300 VA to over 1700 VA.
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- Bridgeport Magnetics IsoPuck provides one of the widest standard ranges, from 200 VA up to 3000 VA. Popular models include the IsoPuck 1200VA and IsoPuck 1800VA, available with 120 V or 230 V input and output options.
Input and Output Configurations
Amgis MEDBOX units generally come with a hospital-grade plug and cord on the input and multiple hospital-grade duplex receptacles on the output.
Triad models often support 120–240 V inputs with flexible receptacle or lead options.
Toroid IsoBox units provide receptacle and cord configurations, with some international models including voltage selection.
Bridgeport Magnetics IsoPuck units typically include a hospital-grade NEMA 5-15P plug on many models but are highly customizable. The IsoPuck 1200VA and IsoPuck 1800VA models can be configured with 120 V or 230 V input/output, flying leads, terminal blocks, or specific connectors.
Customization and Lead Time
Customization speed and flexibility are major decision factors for many buyers.
Amgis MEDBOX is primarily a fixed plug-and-play product.
Triad has solid custom capabilities for modifying standards or building to specification.
Toroid IsoBox offers moderate flexibility with enclosure and mounting choices.
Bridgeport IsoPuck provides very high customization flexibility. Leads, voltages, mounting, and enclosure details can be adjusted to exact needs, with many custom units shipping in 1–2 weeks from their Shelton, Connecticut facility.
Performance and Safety Features
All four brands use toroidal cores, which deliver low EMI, quiet operation, high efficiency, and low leakage current suitable for patient areas.
Amgis MEDBOX includes RFI filtering and inrush current limiting.
Triad emphasizes low stray fields with shielding options.
Toroid IsoBox units are known for low hum and cool running performance.
Bridgeport Magnetics IsoPuck uses electrostatic shielding to help achieve very low leakage current and offers solid epoxy potting to hermetically encapsulate in polycarbonate enclosures for durability.
Certifications and Compliance
All target UL 60601-1, IEC 60601-1, and low leakage requirements for patient care areas.
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- Amgis MEDBOX carries UL listing.
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- Triad maintains extensive medical certifications.
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- Toroid IsoBox holds medical and hospital-grade certifications.
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- Bridgeport Magnetics IsoPuck is UL 60601-1 and Intertek ETL listed with IEC 60601-1 compliance.
Best Fit by Application
You really cannot go wrong with any of these four options. All are reputable toroidal medical isolation transformers that meet relevant safety standards. The best choice usually depends on your specific priorities.
Here is a practical breakdown:
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- Amgis MEDBOX works well when you want a simple plug-and-play solution with multiple hospital-grade outlets and minimal customization.
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- Triad medical isolation transformers are frequently chosen for OEM device integration where low EMI and proven medical-grade performance are priorities.
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- Toroid IsoBox suits hospital and medical use when flexible mounting (wall, cart, or chassis) and a metal enclosure are preferred.
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- Bridgeport Magnetics IsoPuck performs strongly when you need a compact footprint for patient rooms or carts, fast customization, or a combination of plug-and-play multi-device use and custom OEM integration. The IsoPuck 1200VA and IsoPuck 1800VA models are popular when buyers want reliable performance with 120 V or 230 V input/output in either standard or made-to-order configurations.
Space constraints, need for customization, required lead time, and whether the unit will be used in a fixed location or moved frequently are the main factors that usually decide which transformer fits best.
Product Callout Bridgeport Magnetics IsoPuck Series Compact puck-style medical isolation transformers from 200 VA to 3000 VA, including popular IsoPuck 1200VA and IsoPuck 1800VA models. Electrostatic shielding for low leakage, highly customizable leads and configurations (120 V or 230 V input/output), and fast 1–2 week lead times on many custom units. Made in Shelton, Connecticut. UL 60601-1 and IEC 60601-1 compliant.
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FAQ
What is the main difference between these medical isolation transformers? The biggest practical differences are physical size and shape, how much customization is available, and how quickly custom units can be delivered.
Which option is most compact for patient rooms and carts? Bridgeport Magnetics IsoPuck uses a low-profile round puck design that often fits better in tight spaces than traditional rectangular enclosed units.
How customizable are these transformers? Triad and Bridgeport Magnetics IsoPuck both support customization. Bridgeport generally offers the highest flexibility among standard products along with fast lead times on many custom units.
Why does U.S. manufacturing matter for medical isolation transformers? U.S. production typically means shorter and more reliable lead times plus easier access to engineering support.
Which transformer should I choose for portable or multi-device use? Many facilities select compact units like the IsoPuck when equipment needs to move between rooms or support multiple devices in patient care areas.
