60W 120W 240W EDR Din Rail Power Supply 12v 24V for CCTV Application
High-efficiency compact rail-mount unit optimized for steady low-noise security systems, automation racks, and auxiliary control networks.
Stockholm Audio & Power Catalog
Featured Industrial & High-Fidelity Power Assemblies
Direct factory delivery of advanced toroidal components, regulated switching power supplies, and customized DIN rail topologies configured for Swedish professional audio, smart building, and industrial automation demands.
Fullstar Custom EMC LVD CE AC DC Switching Power Supply SMPS 24V 100W 5A
CE/EMC certified enclosed SMPS with minimal ripple, built for studio monitoring gear and high-demand Nordic control installations.
12V 1A AC DC Switching Power Adapter Wall Plug Class VI 100-240V CE FCC
EU plug-compatible external adapter meeting Level VI energy benchmarks, tailored for DACs, preamplifiers, and smart controllers.
High-Voltage AC to DC Switching Power Supply 24V-200V High-Power Series
Configurable high-current SMPS engineered to drive stage power amplifiers, subwoofers, and broad-spectrum laboratory benches.
Universal Multi-Voltage DC Switching Power Adapter 500mA to 3A Series
Flexible output regulation architecture engineered for audio development labs, pedalboards, and prototyping hubs across Kista.
OEM ODM Desktop Power Supply Adapter with Interlocking DC Connectors
Customizable desktop power brick supporting low electrical EMI emission standards for acoustic gear and Smart IoT hubs.
5V 2A/3A Wall Mount AC DC Charger with Integrated Ferrite Noise Suppressor
Equipped with an external ferrite ring to eliminate common-mode high-frequency spikes in sensitive digital audio interfaces.
Variable Voltage Power Supply 240W Dual AC 110V/230V Converter
Switchable input voltage converter with stabilized heavy-duty DC rails, optimal for commercial stage and lighting controllers.
Engineering White Paper
Acoustic Purity, Low Stray Flux & Precision Toroidal Geometries
Comprehensive technical overview of how Shaanxi Zelqo Power co-engineers toroidal magnetic transformers for high-end audio amplification and mission-critical Nordic installations.
In high-fidelity audio reproduction, the power supply transformer constitutes the foundational core of analog signal integrity. For audiophile hardware brands, stage audio engineers, and sound installation specialists across Stockholm, Gothenburg, and Uppsala, standard laminated iron core (EI) transformers often introduce unwanted acoustic hum, mechanical vibrations, and stray electromagnetic interference (EMI). Shaanxi Zelqo Power Co., Ltd. solves these critical audio engineering bottlenecks through custom-built Audio Amplifier Toroidal Transformers produced in an Intertek-verified production facility.
Unlike standard EI laminations that display sharp 90-degree magnetic paths and air gaps, a continuous grain-oriented silicon steel (CRGO) circular core features no air gap whatsoever. This seamless ring structure keeps the magnetic flux tightly constrained inside the core lamination. Consequently, our audio-grade toroidal transformers radiate approximately 85% to 90% less stray magnetic field than conventional EI transformers. For professional audio amplifiers, dual-mono high-end power stages, and studio recording preamplifiers designed in Sweden, this architectural advantage prevents induced 50 Hz/100 Hz hum in sensitive audio stages and PCB copper traces.
"Acoustic purity in high-fidelity equipment depends entirely on the signal-to-noise ratio (SNR) maintained across dynamic transients. Our custom winding topologies, featuring copper foil electrostatic shielding and secondary center taps, ensure flawless sonic depth under severe Swedish grid transients."
Stockholm’s professional audio community—encompassing high-end mastering suites in Södermalm to live acoustic equipment installations in the Avicii Arena—demands components that operate silently even under high instantaneous current draw. When an audio power amplifier renders explosive low-frequency transients, the power transformer must supply vast instantaneous current without undergoing core saturation. Our design process factors in cold-rolled high-permeability steel, optimal copper-fill factors, Class H (180°C) copper wire, and specialized epoxy-resin potting cups that eliminate mechanical microphonics entirely.
Zero Mechanical Hum
Continuous wound-tape silicone steel cores combined with high-grade vacuum pressure impregnation (VPI) eradicate audible laminated chatter in quiet sound studios.
Reinforced Dielectric Safety
Engineered to comply with EN 61558-1 and EN 61558-2-4 standards, delivering over 4.0 kV dielectric isolation between primary and balanced secondary output rails.
Instantaneous Surge Headroom
Ultra-low DC winding resistance (DCR) guarantees dynamic transient response during high-power musical peaks in Class A and Class AB speaker amplifiers.
Electrostatic Shielding
Integrated inter-winding copper foil shields drain common-mode high-frequency utility noise straight to ground before it pollutes the downstream rectifier stage.
Market Integration
Localized Application Scenarios Across the Stockholm Region
From boutique consumer electronics in Stockholm’s inner city to high-capacity automation hubs in Kista Science City, our magnetic products serve dedicated niche sectors.
Boutique Hi-Fi & Tube-Solid Hybrid Amplifiers
Stockholm is home to a world-renowned community of audio designers, recording studios, and discerning audiophiles who favor bespoke tube and Class A solid-state amplifiers. Our custom toroidal units provide multi-tap secondary windings—simultaneously delivering high-voltage B+ plates, filament heater voltages, and low-noise operational amplifier dual rails (e.g., ±15V, ±45V) in a single compact footprint with minimal radiant field.
Commercial Concert Halls & Public PA Systems
Venues across the Stockholm metropolitan area require robust public address systems and concert amplification systems running 24/7. These installations require transformers with heavy duty cycle capacity and embedded thermal cut-offs (PTC/thermal switches at 115°C/130°C) that protect equipment enclosures from thermal runaway during prolonged multi-channel concerts.
Smart Building Automation & Clean Lab Racks
In data-driven environments such as telecom centers and R&D laboratories in Kista, power quality cannot be compromised. Our enclosed switching supplies and toroidal isolation transformers supply clean power to industrial control cabinets, elevator automation controllers, and sensitive acoustic sensor test benches where grid harmonic distortion must be thoroughly decoupled.
Market Evolution
Swedish & Nordic Industry Trends Shaping Transformer Procurement
Procurement strategies across Scandinavia are rapidly transitioning toward sustainability, eco-design directives, and uncompromising electromagnetic safety.
EU Ecodesign & No-Load Loss Directives
Sweden maintains rigorous green building and energy preservation directives. Modern procurement specifications prioritize transformers with negligible no-load (quiescent) magnetizing losses. Toroidal geometries naturally exhibit near-zero eddy-current losses due to oriented grain crystal structures, assisting Nordic OEM clients in passing ERP eco-efficiency benchmarks.
Electromagnetic Cleanliness (EMC/RoHS/REACH)
Swedish buyers strictly enforce Elsäkerhetsverket (Swedish Electrical Safety Agency) parameters and CE directives (EMC Directive 2014/30/EU and Low Voltage Directive 2014/35/EU). By selecting verified oxygen-free pure copper windings and non-toxic flame-retardant epoxy (UL94V-0), our factory enables seamless European regulatory clearances.
Demand for Agile Custom OEM/ODM Prototyping
Rather than locking procurement into off-the-shelf industrial component catalogs that force chassis layout compromises, Swedish engineers are choosing custom prototyping. We provide swift turnarounds for sample development—allowing audio hardware startups to tweak output volt-amps, center mounting cups, and silicone flying lead terminations rapidly.
Verified Manufacturing Capability
Shaanxi Zelqo Power: Verified Factory Direct Excellence
Intertek on-site verified production facilities, backed by 25+ automated manufacturing and QC inspection stations in Xi'an, China.
Shaanxi Zelqo Power Co., Ltd. (Room 1306, Poly Zhongda Plaza, Fengcheng 10th Road, Xi'an) is a specialized manufacturer and exporter of precision magnetics and power solutions. Built upon dedicated engineering, our facilities support end-to-end custom production for toroidal, high-frequency, and low-frequency transformers, along with industrial-grade switching power supplies and AC-DC adapters.
Strict Multi-Stage Quality Control Protocol:
- LCR Digital Bridge Testing: Verifies core inductance, secondary phase continuity, and ultra-low leakage inductance.
- DC Low-Resistance Bridge: Ensures winding copper gauge precision and coil thermal equilibrium.
- Impulse Winding & Inter-Turn Insulation: Detects micro-fractures in enamel insulation before encapsulation.
- Hi-Pot Dielectric Voltage Proof: 100% batch insulation screening up to 4000V AC to guarantee operator and listener safety.
- Digital Power Meter & Aging: Precise measurement of quiescent loss, efficiency percentages, and full-load thermal burn-in.
Buyer Support & Technical Questions
Frequently Asked Questions by Swedish Procurement Managers
Answers to common inquiries regarding electrical parameters, sample validation, Nordic shipping, and compliance certification.
What specific electrical inputs and outputs are standard for Stockholm audio devices?
Sweden operates on a nominal 230V AC mains at 50 Hz. We design custom primaries supporting single 230V or dual 115V/230V windings with static shields. Secondaries are completely tailored to your amplifier requirements—such as dual 24V, 35V, 45V, or 50V AC rails for solid-state power amps, alongside auxiliary 12V or 15V taps for DACs and pre-amp boards.
How do your audio amplifier toroidal transformers minimize acoustic hum and audible buzzing?
Acoustic hum stems from either core magnetostriction or loose copper windings vibrating against each other. We use continuously wound grain-oriented silicon steel rings with high magnetic saturation, secure them with tension-controlled circular winding machines, vacuum-impregnate the structure with low-noise varnish, and offer center-potted epoxy fills inside metal or plastic enclosure cups to ensure near-silent operation in critical audio rooms.
Can you assist with CE, RoHS, and EU safety certification compliance?
Yes. Our transformers are constructed using UL and CE-recognized insulation materials (flame-retardant tapes, Class B/F/H wire, and fire-resistant encapsulation resins meeting UL94V-0). We build to IEC/EN 61558-1 and IEC/EN 62368-1 standards. Project-specific test records and dielectric safety declarations are provided with commercial orders.
What are your typical prototype sample and production batch lead times for Sweden?
Rapid prototyping takes approximately 4 to 7 working days once electrical specifications are confirmed. Production runs generally ship within 15 to 22 working days. We coordinate air express shipments directly to Stockholm Arlanda Airport (ARN) for rapid engineering validation or sea freight consolidation to Göteborg/Stockholm ports for regular production inventory.
Do you accommodate custom mechanical enclosures, mounting plates, and cabling?
Yes. We offer complete mechanical customization: center-hole screw mounting with neoprene rubber pads, steel clamping discs, PCB-mountable potted pins, threaded base inserts, internal magnetic flux band shielding (copper or G/O silicon bands), and customized lead lengths with your preferred crimp terminals or connectors.
Start Your Custom Audio Transformer or SMPS Project Today
Connect directly with our engineering team in Xi'an. We review your audio schematic, compute optimal core geometries, and deliver verified magnetics to your facility in Stockholm with zero compromise on acoustic clarity.