Power-One LKP 5744-9ER AC-DC Converter 25-28V 4A
The Power-One LKP 5744-9ER is a compact, enclosed AC-DC power supply delivering adjustable output voltage from 25 VDC to 28 VDC at 4 A continuous (100 W max). It features universal AC input (85–264 VAC, 47–63 Hz) and a rugged metal chassis suitable for industrial automation, telecom base stations, and LED lighting drivers. The unit operates in natural convection cooling with an efficiency of up to 87%.
Electrical Specifications
Input Voltage: 85–264 VAC (or 110–370 VDC)
Output Voltage: Adjustable 25–28 VDC via potentiometer (default 27.6 VDC)
Output Current: 4 A continuous (5 A peak for 30 seconds)
Line Regulation: ±0.5%
Load Regulation: ±1.0% (0–100% load change)
Ripple and Noise: 150 mVpp (20 MHz bandwidth)
Protection Features
The power supply includes overvoltage protection (crowbar at 32 VDC), overcurrent protection (hiccup mode with auto-recovery), short-circuit protection (continuous, non-latching), and overtemperature shutdown (thermostat at 100°C, auto-reset). Input fuse is internal (slow-blow 5A). Output isolation is 3000 VAC between input and output, and 1500 VAC between output and chassis.
Mechanical and Environmental
Dimensions: 199 mm x 98 mm x 38 mm (L x W x H). Weight: 0.9 kg. Mounting: screw holes for base or side mounting. Operating temperature: -20°C to +70°C (derate linearly above 50°C to 50% load at 70°C). Storage: -40°C to +85°C. Humidity: 10–90% non-condensing. The unit meets EN 55022 Class B for EMI and EN 61000-3-2 for harmonics.
Terminals and Indicators
Input and output connections are via screw terminal blocks (accept up to 12 AWG wire). A green LED indicates output power good. A second LED (yellow) signals overtemperature or overload. An output voltage adjust pot is accessible from the front. The chassis includes a grounding stud for safety earth.
Certifications and Reliability
Approvals: UL 60950-1, CSA C22.2, TÜV EN 60950-1, CE, and RoHS. MTBF per MIL-HDBK-217F (ground benign) is 150,000 hours. The LKP series is known for long life due to Japanese electrolytic capacitors (rated 105°C). Suitable for battery charging (float charge setting of 27.6 VDC), PLC power supplies, and test equipment.
