LEYU LRS-150-24 150W 24V 6.5A AC DC Switching Power Supply Low Profile
Input: 85-264VAC
Efficiency: >89%
Cooling: Convection
Profile: 30mm Enclosed
Catalog & Engineering Recommendations
Featured Industrial & Dual-Output Ready Power Solutions
Below are eight core power supply configurations engineered by leading Zhejiang industrial facilities. These models support mission-critical telemetry, industrial automation, and custom OEM secondary auxiliary loops with certified MTBF metrics.
3000W High Power Lab Bench Power Supply 0-24V 0-48V 0-110V Variable SMPS
Regulation: CV / CC
Display: 4-Digit Digital
Protection: OVP/OCP/OTP
Use: Aging & Testing
SP-500-12 12V 40A 500W Switching Power Supply with Active PFC & Cooling Fan
Input: 88-264VAC
Current: 40A Continuous
PFC: Built-in Active
Thermal: Auto Speed Fan
500W 24V 20A Switching Power Supply AC DC Converter Single & Dual Rails
Input Range: Switchable
Ripple: <150mVp-p
Efficiency: 88.5%
Housing: Perforated Metal
MDR-20 20W DIN Rail Switching Power Supply 12V 1.67A / 24V 1A Industrial
Mounting: DIN TS-35/7.5
No-Load: <0.75W
DC OK: Active Relay
Class: Class I Div 2
LDV-100 100W IP67 Waterproof LED Power Supply 12V 8.3A / 24V 4.2A Adapter
Ingress: IP67 Sealed
Surge: L-N 2KV / GND 4KV
Potting: Thermally Conduc.
Warranty: 3 Years Full
3000W High Voltage DC Power Supply 110V 27.3A Adjustable SMPS 220V to 110V
Output: 110VDC Regulated
Current: 27.3A Peak
Remote: 0-5V/0-10V Analog
Topology: Full-Bridge Soft
NDR-240 240W DIN Rail Power Supply Universal 90-264VAC Active PFC 24V/48V
Width: Slim 63mm
Efficiency: 90% Peak
PFC: PF >0.98 Full Load
Standards: UL508, EN62368
18+
Years Power Electronics R&D
100%
Full-Load Burn-in Aging Tested
TÜV
Rheinland Onsite Verified Facility
±1.5%
Dual-Output Cross-Regulation Precision
Whitepaper Architecture
Engineering Dual Output Power Supplies: Topologies, Cross-Regulation & Reliability
In industrial control panels, robotics, telecommunications, and Medical/Laboratory equipment, a dual output power supply converts AC mains voltage into two independent or semi-independent DC voltage rails (e.g., +5V/+12V, +12V/+24V, +5V/+24V, or symmetric ±12V/±15V). Achieving tight voltage stability across varying load dynamics requires advanced power electronics design.
1. The Core Engineering Challenge: Solving the Cross-Regulation Bottleneck
Unlike single-output switch-mode power supplies (SMPS) where a single closed-loop optocoupler monitors and regulates the output rail via Pulse Width Modulation (PWM), dual output converters face cross-regulation asymmetry. When Rail 1 (typically the main feedback rail, e.g., 5V logic) is heavily loaded while Rail 2 (e.g., 24V motor/relay drive) is lightly loaded or idling, the duty cycle expands to maintain Rail 1 voltage. Without dedicated secondary regulation, this creates energy spillover across the secondary windings, driving Rail 2 voltage out of specification.
Top tier Chinese manufacturers solve this problem using three primary topological methodologies:
- Coupled Inductor Smoothing: By winding the filter inductors of both outputs onto a single core with turns ratios closely matched to the secondary voltages, leakage inductance energy is redistributed magnetically, reducing cross-regulation error to under ±5% across a 10% to 100% load differential.
- Synchronous Secondary Buck Post-Regulators: In high-precision automation systems, the primary SMPS transformer steps down to a single master rail (e.g., 24V), while a high-efficiency DC-DC synchronous buck regulator steps down to the secondary auxiliary rail (e.g., 5V or 3.3V). This completely eliminates cross-regulation interaction, offering ±1% regulation on both channels.
- MagAmp (Magnetic Amplifier) Post-Regulation: Frequently applied on secondary outputs carrying high peak currents, saturable reactor cores effectively gate secondary conduction pulses independently from the primary feedback loop.
2. Dual Output Circuit Topologies Compared for B2B Sourcing
Selecting the appropriate circuit configuration impacts Bill of Materials (BOM) cost, operational lifespan, and electromagnetic interference (EMI) compliance. Below is an engineering evaluation across widely manufactured Chinese topologies:
| Circuit Topology | Typical Power Range | Galvanic Isolation | Cross-Regulation Precision | Efficiency Benchmark | Ideal Application Profile |
|---|---|---|---|---|---|
| Multi-Winding Flyback | 15W – 120W | Isolated or Shared GND | ±6% to ±10% on Aux Rail | 82% – 87% | CCTV cameras, basic relays, edge IoT controllers |
| Two-Switch Forward Converter | 100W – 350W | Isolated Secondaries | ±3% to ±5% with coupled choke | 86% – 90% | Laser cutting heads, small industrial CNC drives |
| LLC Resonant Half-Bridge + DC-DC | 250W – 800W | Fully Isolated Rails | ±1% (Zero Interaction) | 92% – 95% | High-end test benches, medical analytics, robotics |
| Push-Pull / Full-Bridge Phase Shift | 800W – 3000W+ | Reinforced Isolation (3-4kVAC) | ±0.5% (Dual Closed Loops) | 90% – 94% | High power lab supplies, semiconductor burn-in racks |
3. Strategic Global Procurement Trends (2025–2030)
B2B buyers, OEM system integrators, and electrical procurement directors face shifting requirements when sourcing power units from China. Supply chain decisions in 2025 and beyond are governed by four macro trends:
A. WBG Semiconductor Adoption (GaN & SiC): Gallium Nitride (GaN) high-electron-mobility transistors (HEMTs) and Silicon Carbide (SiC) Schottky diodes are transitioning from consumer chargers into industrial-grade dual-output power modules. WBG devices reduce switching losses by up to 50%, enabling switching frequencies above 150kHz. For OEM buyers, this translates to a 30% reduction in chassis dimensions (such as ultra-slim 1U or DIN rail widths) and significantly cooler operation in unventilated IP65/IP67 enclosures.
B. Zero Minimum Load Demand: Traditional multi-output switching supplies required a 10% minimum load on the primary output to prevent the auxiliary output from dropping out of regulation. Modern industrial control directives require power supplies to sustain tight tolerances even under zero-load standby states (standby consumption <0.3W per IEC 62301 standard), compelling manufacturers to integrate burst-mode controllers and active bleeding circuits that switch out during active run mode.
C. Unified Safety Harmonization (IEC/EN/UL 62368-1 Edition 3): Legacy standards like IEC 60950-1 (IT) and IEC 60065 (AV) have been completely deprecated. Global buyers must guarantee that Chinese vendor factories have updated component creepage and clearance distances, transformer reinforced barrier insulations, and flammability certifications (UL94 V-0 plastics) compliant with the Hazard-Based Safety Engineering (HBSE) framework of IEC 62368-1.
D. Digital Telemetry via PMBus & IO-Link: Industrial DIN rail dual supplies are increasingly expected to communicate rail voltages, temperature, load current, and fault codes to PLCs via I2C, PMBus, or Modbus interfaces, enabling predictive maintenance before catastrophic line shutdowns occur.
Factory Capability & E-E-A-T Authority
Why Yueqing Keldan Technology Co., Ltd. Leads China's SMPS Manufacturing
Located in Yueqing, Wenzhou—the globally recognized capital of low-voltage electrical apparatus in Zhejiang Province—Yueqing Keldan Technology Co., Ltd. brings over 18 years of specialized manufacturing experience, verified on-site by TÜV Rheinland.
Verified Production Infrastructure, Verified QA/QC Protocols
Rather than functioning as an intermediary trading entity, Keldan operates dedicated surface mount technology (SMT) production lines, wave soldering ovens, automated optical inspection (AOI) chambers, and multi-tier burn-in aging racks.
Every batch of industrial switching supplies, DIN rail modules, and high-power DC converters is subjected to rigorous quality gates designed to screen infant mortality failures before international container dispatch.
- TÜV Rheinland Audited: Complete onsite verification covering production equipment, employee technical competency, and supplier auditing systems.
- 100% Dynamic Full-Load Burn-In: Every power supply runs through multi-hour elevated-temperature thermal chambers under cycling resistive and inductive loads.
- Surface Mount Technology (SMT) Precision: High-speed pick-and-place lines with reflow thermal profiling to eliminate cold-solder bridges and void defects.
- Automated Optical Inspection (AOI): High-resolution optical scanning of solder fillets, component polarities, and miniature SMD passive devices.
- R&D Engineering Staff: Dedicated engineering specialists with 5+ years of SMPS design experience ready to customize dual-voltage outputs, housings, and terminals.
- 10+ Years International Export Expertise: Fully compliant documentation, CE certification reports, RoHS compliance declarations, and export packing.
The 8-Stage Zero-Defect Manufacturing Pipeline
1
IQC Component Screening: Strict AQL testing on magnetic cores, primary electrolytic capacitors (105°C rated), and MOSFET switches.
2
SMT Automated Assembly: Placement of SMD passives, PWM control ICs, and high-frequency secondary rectifiers.
3
Dual-Wave Soldering: Lead-free RoHS soldering of power transformers, large bulk caps, and terminal blocks.
4
AOI & Visual Solder Gate: 100% automated optical check supplemented by certified QC inspectors.
5
Manual Debugging & Voltage Trimming: Potentiometer calibration of dual rails to precisely achieve factory setpoints.
6
Full-Load High-Temperature Burn-In: Continuous multi-hour operational stress test in dedicated aging racks.
7
Hi-Pot & Safety Ground Continuity: 3.0kVAC dielectric breakdown insulation barrier test between primary and secondary.
8
Final OQC & Barcode Tracking: Cosmetic review, anti-static moisture-barrier packaging, and batch serialization.
Engineering Buyer's Playbook
How to Properly Specify Dual Output Switching Supplies
Procurement errors account for up to 60% of field returns in automated systems. Follow these four engineering rules when preparing a Request for Quotation (RFQ) for Chinese factories.
1. Define Isolation Between Outputs
Determine whether your application requires Common Ground (non-isolated) or Galvanically Isolated Secondaries. Non-isolated dual outputs (sharing a common 0V return) work for general logic + relay circuits. High-noise stepper motor drives or sensitive medical transducers require 500VDC or 1.5kVAC galvanic isolation between Rail 1 and Rail 2 to prevent ground loops.
2. Calculate Symmetrical & Asymmetrical Loads
Never specify only the nominal wattages. Provide your supplier with the minimum, typical, and maximum peak current for both rails (e.g., Rail 1: [email protected] min / 4A max; Rail 2: 24V@0A min / 6A peak). If Rail 2 drops to zero while Rail 1 stays active, the factory must integrate active pre-load circuitry or use secondary post-regulators to avoid voltage runaway.
3. Account for Inductive Inrush Current
When driving solenoids, contactors, or DC brushless fans on the secondary rail, starting currents can spike 300% to 500% above steady-state. Select models equipped with Constant Current Limiting protection rather than instant "Hiccup Mode" shutoff, ensuring your inductive actuators can energize without causing logic reboots on Rail 1.
Procurement & Technical FAQ
Frequently Asked Questions by Industrial Sourcing Teams
Direct technical answers addressing the most common concerns of OEM engineers, distributors, and procurement directors sourcing power supplies from China.
What causes cross-regulation voltage drift on dual-output power supplies, and how is it resolved?
Cross-regulation drift occurs because the main feedback optocoupler only monitors one primary output rail (typically the high-current or logic rail). When the secondary rail experiences large load swings while the primary rail load remains static, the transformer secondary windings experience unbalanced leakage inductance drops. To resolve this, Keldan employs coupled inductors where magnetic flux shares regulation energy between windings, or implements independent synchronous DC-DC step-down converters for secondary auxiliary voltages, holding both outputs within ±1.5% tolerance regardless of load distribution.
Is Yueqing Keldan Technology Co., Ltd. a direct manufacturing factory or an export intermediary?
Yueqing Keldan Technology Co., Ltd. is an on-site verified custom manufacturing enterprise with its headquarters and manufacturing plants located in Malujiao Village, Beibaixiang Town, Yueqing, Wenzhou, Zhejiang, China. Our facilities, machinery (SMT mounters, wave soldering, AOI machines), QA/QC protocols, and trading licenses have been officially inspected and certified onsite by TÜV Rheinland. We handle design, tooling, SMD assembly, burn-in aging, and export documentation with our in-house engineering and trading departments.
What is the difference between isolated dual outputs and common-ground dual outputs?
Common-ground dual outputs share a single return terminal (COM or 0V) on the secondary side. This configuration is economical and well-suited for unified systems, such as a controller utilizing 5V for microprocessor logic and 12V for signaling relays. Galvanically isolated dual outputs provide two completely separate, insulated secondary circuits with high dielectric withstand capabilities (typically 500VDC to 1500VAC). Isolated outputs are critical when separating noisy electrical actuator circuits from sensitive analog acquisition channels, or when establishing positive and negative split rails (±12V or ±15V) by linking opposite polarity terminals.
What Minimum Order Quantity (MOQ) and production lead times apply for custom OEM dual output supplies?
For standard catalog products (such as our single-output LRS series, MDR DIN rail modules, and standard enclosed chassis), sample units are available from 1 piece, while standard volume cartons start from 10 to 15 pieces. For customized OEM/ODM projects involving custom output voltage combinations (e.g., custom 5V/48V or 15V/28V rails, specialized metal enclosures, conformal coating, or proprietary cable harnesses), initial project prototype runs typically require an MOQ of 100 to 500 units depending on transformer tooling requirements. Typical lead time is 7-10 working days for pilot samples and 18-25 days for containerized batch production.
How does Active Power Factor Correction (PFC) benefit industrial power installations?
Active PFC circuits (featured on units like the SP-500 and NDR-240 series) utilize a dedicated boost converter to shape the AC input current waveform, aligning it in phase with the AC mains voltage. This increases the Power Factor from ~0.6 (typical in low-cost passive supplies) to >0.95 or >0.98. For industrial facilities, Active PFC reduces RMS current draw through building cabling, suppresses harmonic distortion compliant with EN 61000-3-2 Class A/D standards, prevents neutral line overheating in three-phase power feeds, and protects power supplies from tripping sensitive circuit breakers during parallel operation.
How are Keldan power supplies tested for thermal reliability and Mean Time Between Failures (MTBF)?
MTBF metrics are calculated using Telcordia SR-332 (Bellcore) standards and verified empirically through accelerated life testing. During manufacturing, every finished assembly undergoes a 100% full-load burn-in process running for 2 to 4 hours in elevated temperature testing racks (up to 45°C ambient) with rapid on/off switching cycles. In addition, critical components are over-specified: primary electrolytic capacitors are rated for 105°C long-life operation, high-voltage switching MOSFETs utilize low-RDS(on) silicon with robust heat sinking, and all models undergo a 3000VAC Hi-Pot primary-to-secondary dielectric withstand test to guarantee long-term field reliability exceeding 200,000 to 300,000 hours of continuous operation.
Ready to Engineer or Source Your Dual Output Power Supply?
Send us your required voltage rails, continuous current ratings, isolation parameters, and target certifications. Our Yueqing engineering team provides comprehensive datasheets, 3D CAD step files, and factory-direct volume pricing within 24 business hours.
