Isolation Transformer 2.5 VA 2 x 115V 2 x 10V 120 mA - Low-Noise Power

In this review the Isolation Transformer 2.5 VA is evaluated for use in small electronics projects and repair benches. The bottom line: this compact, low-power unit is best for designers and hobbyists who need reliable galvanic isolation and clean low-voltage secondaries for signal-level circuits. The review finds the transformer delivers quiet performance and flexible winding options in a small PC pin thru-hole package, making it a straightforward choice when a modest 2.5 VA isolation solution is required.

Key Features

• Dual primary windings: two 115V primaries allow series or parallel configuration for flexible input wiring and compatibility with different supply arrangements.
• Multiple secondaries: two 10V secondaries give separate isolated outputs for dual-rail or isolated signal supplies without needing extra components.
• Thru-hole PCB mounting: PCB pin construction makes the transformer easy to secure on a board and suitable for permanent installations or prototyping fixtures.
• High isolation rating: 4200 Vrms isolation provides strong protection between primary and secondary for safety in sensitive electronics applications.
• Compact 2.5 VA rating: low-rated power is ideal for small sensors, op amp supplies, and signal conditioning where heat and size must be minimized.

Who It's For

This transformer suits electronics hobbyists, DIY audio builders, and engineers working on small instrumentation or control circuits that require galvanic isolation and low current secondary supplies. The small footprint and PC pin thru-hole format make it convenient for custom PCBs and fixed installations where a modest power budget is acceptable.

It is not intended for high-power applications, power distribution, or mains-driven motors; users needing more than 120 mA or a higher VA rating should look for a larger unit. Also, projects requiring integrated regulation or thermal management will need additional parts around this transformer.

Pros & Cons

Pros

• Provides robust isolation up to 4200 Vrms, which enhances safety in signal circuits.
• Two 115V primaries and two 10V secondaries offer wiring flexibility for series/parallel configurations.
• PCB pin thru-hole design makes mounting and soldering straightforward for board-level use.
• Low noise and compact size work well in bench power and instrumentation projects.

Cons

• At 2.5 VA and 120 mA output, it is limited to low-power applications and cannot power larger loads.
• Thru-hole mechanical mounting may require additional rigidity or glue for vibration-prone environments.

Specifications

Manufacturer	Triad Magnetics
Rating	2.5 VA
Primary	2 x 115V
Secondary	2 x 10V
Output Current	120 mA
Dielectric Withstand	4200 Vrms
Mounting	PC pin thru-hole, 8 terminals

Our Verdict

For small-scale electronics work that needs dependable galvanic isolation and flexible secondary windings, this 2.5 VA isolation transformer represents sensible value. It is compact, easy to mount on a PCB, and rated for high isolation, making it a good match for hobbyists and engineers designing low-current signal supplies; users with larger power needs should choose a higher VA unit.

Frequently Asked Questions

Can the primaries be wired in series for 230V input?
Yes, the two 115V primaries can be connected in series for 230V operation if the circuit and safety requirements allow it.

What is the maximum output current per secondary?
The total rated output is 2.5 VA with 120 mA; use the windings within that current limit and check combined loading when paralleling secondaries.

Is this suitable for audio applications?
It can be used for low-power audio or signal circuits where isolation is needed, but performance depends on circuit design and whether the VA rating meets the load.