Ametek / Elgar / California Instruments 251TL-115V-OP1 Low Noise Linear AC Power Source

The Ametek Elgar California Instruments 251TL-115V-OP1 is a low-noise linear AC power source delivering 250 VA of regulated power with dual output voltage ranges and extended frequency capability. Built on the proven TL Series architecture, this unit combines linear amplifier design with precision voltage and frequency control to supply clean, stable AC waveforms for sensitive equipment testing and operation.

Technical Specifications

• Rated output: 250 VA, with power derating to 78% of voltage range


• Dual voltage ranges: 0–270 V RMS (high) and 0–135 V RMS (low)


• Voltage accuracy: ±0.1% of range; regulation ±0.025% of full scale


• Maximum RMS current: 1.2 A (270 V range) / 2.4 A (135 V range)


• Current accuracy: 0.2% FS + 0.3% reading (peak current); adjustable current limit within ±2% accuracy Frequency & Waveform Quality


• Frequency range: 16 Hz to 8000 Hz with 1 Hz resolution


• Frequency accuracy: ±0.1% at 100 Hz; 0.01 Hz accuracy from 16–100 Hz


• Total harmonic distortion: 60 dB RMS (40 Hz–8000 Hz); maximum –73 dB


• Crest factor: 4:1 Measurements & Control (Option -OP1)


• Direct LCD readout of voltage, current, peak current, power, and power factor


• Voltage and current measurement accuracy: within 2%


• IEEE-488 and RS232C remote control interfaces


• IEEE functions: SH1, AH1, T8, L3, RL2


• RS232C settings: 19200 baud, 8 bits, no parity, 1 stop bit


• SCPI command language; TTL remote inhibit and function strobe (active low, BNC) Environmental & Physical


• Dimensions: 5.25 × 19 × 22 inches (133 × 483 × 560 mm)


• Net weight: 75 lbs (34 kg)


• Operating temperature: 0–40 °C; storage: –40 to +85 °C


• Contains ESD-sensitive ports; ESD safety procedures required during installation

Key Features

• Linear amplifier topology ensures minimal noise and distortion for precision testing


• Dual voltage ranges simplify configuration for global power requirements


• Extended frequency range to 8000 Hz supports conventional and special-purpose applications


• Integrated measurement and monitoring via standard instrument interfaces


• Direct voltage, current, and power factor display eliminates external instrumentation

Typical Applications

• Testing and powering of audio and precision measurement equipment


• Validation of power supply performance under variable frequency conditions


• Component characterization requiring low-distortion AC excitation


• Laboratory and production environments demanding clean sinewave sourcing