The Astec NTS503 500-W ac-dc power supply offers power density of 11.9 W/in.3 A convection-cooled model outputs 200 W, while the fan-cooled version delivers 500 W up to 50°C with 30-cfm forced air.
The supplies generate a 12-V output to power boards fitted with multiple nonisolated point-of-load dc-dc converters. The convectioncooled model delivers 16.6 A, and the forced-air version delivers 41.7 A. An auxiliary “always-on” regulated 5 Vdc @ 2-A output for standby operation and a 12-V output for powering fans are included. A universal input accepts 85 to 265-Vac at any frequency from 47 to 440 Hz. The active power-factor correction minimizes input harmonic current distortion.
Built-in control and monitoring features include “ac power fail” and “dc OK” output signals; a remote on/off input; overvoltage, shortcircuit, and overtemperature conditions protection. The power supply has an internal O-ring diode on its main 12-V output for fault-tolerant and N+1 redundancy applications. The main 12-V output is adjustable to 5% either side of nominal with an internal trim potentiometer or through the digital interface. Regulation is maintained to within ±2% for all line and load conditions. Differential remote sense facilities compensate for a 0.5-V drop between the output terminals and the load. The auxiliary 5-Vdc output is regulated to within ±5% and delivers 2.0 A.
