Wavelength Electronics LFI-3751

The Wavelength Electronics LFI-3751 is a precision temperature controller for sensitive thermal management applications. It delivers ±5 A output current to thermoelectric coolers or resistive heaters with ±9.5 V compliance voltage, achieving up to 40–45 W output power. The instrument maintains temperature stability better than 0.001°C over one hour with thermistors and 0.003°C over 24 hours, making it suitable for quantum technology, medical diagnostics, and spectroscopy systems requiring tight thermal control.

The LFI-3751 features Autotune PID optimization that adapts control loop parameters to load characteristics, reducing overshoot and stabilizing performance across varying thermal conditions. A digital PID mode is available for improved stability with low-resolution sensors. Autoranging sensor bias currents optimize signal-to-noise ratio across thermistor, RTD, and IC sensor inputs (AD590, LM335, LM35). Front panel control includes a 4-digit display showing temperature, resistance, output current, and voltage, with adjustable heat and cool current limits plus high/low temperature shutdown thresholds.

– Technical Specifications

• Output Current: ±5 A (TEC or RH)
• Compliance Voltage: ±9.5 V
• Output Power: 40–45 W
• Temperature Stability: <0.001°C/hour (thermistor, +25°C); <0.003°C/24-hour
• Sensor Types: Thermistors, RTDs, IC sensors (AD590, LM335, LM35)
• Control Loop: Autotune PID with digital PID option
• Input Power: 115/230 VAC, 50/60 Hz (100–240 VAC range)
• Operating Altitude: Up to 6500 ft (2000 m)
• Operating Temperature: Up to 31°C at 80% RH (50% RH at 40°C)
• CE Compliant: Yes

– Key Features

• Autoranging sensor bias currents for optimal SNR
• Front panel sensor calibration
• Adjustable current and temperature limits with shutdown
• 4-digit display readout

– Control Interfaces

• Front panel operation
• RS-232 (addressable)
• USB (WCB404 adapter cable may be required)
• Remote analog setpoint input (analog version)

– Compatibility & Integration

• LabVIEW drivers (free)
• Benchlink software for PC-based front panel emulation
• Indoor use, Pollution Degree 2, Overvoltage Category 2