Ametek / Elgar 251B Single Phase Output AC Power Source

The Ametek/Elgar 251B is a solid-state linear AC power source delivering 250 VA single-phase output across three programmable voltage ranges. This frequency-agile instrument generates stable, low-distortion sine waves for benchtop and 19-inch rackmount applications, functioning as a versatile frequency converter and power simulator for demanding test environments.

Technical Specifications

• Output power: 250 VA


• Output voltage ranges: 0–32 VAC, 0–130 VAC, 0–260 VAC


• Input: 115 VAC ±10% or 230 VAC ±10%, 47–63 Hz, single phase Frequency & Distortion


• Output frequency: 45 Hz to 5 kHz at full rated power; 5 kHz to 10 kHz at half power; optionally expandable to 10 kHz


• Harmonic distortion: typically <0.3% midband; typically <0.6% across full frequency range


• Frequency control via fixed, variable, or programmable oscillators (sold separately); tolerances to ±0.0001% available Physical & Environmental


• Form factor: benchtop or 19-inch rackmount


• Dimensions: 5.25" H × 19" W × 16" D


• Weight: 70 lbs


• Enclosure: aluminum (benchtop) or steel (rackmount with slide-out capability)

Key Features

• Continuous duty operation at 150% rated capacity; 100% capacity into linear resistive loads


• Overload and over-temperature protection


• Clean sine wave output suitable for linear loads and ATE systems


• Modular design supports single, dual, and three-phase configurations when combined with routing plug-ins and oscillators

Typical Applications

• Linear load testing and power supply validation


• Automatic Test Equipment (ATE) integration


• Avionics testing (including 400 Hz operation)


• AC frequency conversion (50 Hz ↔ 60 Hz)


• Bench research and development

Compatibility & Integration The 251B operates as a building block in multi-phase systems. Documented configurations include System 500-1 (2× 251B, 500 VA single-phase at 65/130/260 VAC), System 500-2 (250 VA per phase dual configuration), System 500-30 (166 VA per phase three-phase open-delta), and System 500-3Y (166 VA per phase three-phase phantom-wye).