The Woodward L-Series Air/Fuel Ratio Control provides precise closed-loop air-fuel ratio management for four-stroke gaseous-fueled engines operating at near-stoichiometric ratios with three-way catalytic converters. Working with the LC-50 family of integrated throttles and mixers, it covers engines between 5 and 100 kW (7–134 hp), supporting fuel qualities from low-quality pipeline natural gas to HD-5 LPG (propane).

Key Features
Control
- Microprocessor-based closed-loop air/fuel ratio control
- Pre-catalyst exhaust oxygen (HEGO) sensor feedback
- Automatically maintains optimum air/fuel mixture without operator supervision
- Maximizes catalyst life and emissions compliance
- Compatible with fuel qualities from 850 to 2,325 BTU/SCF
- On-the-fly switchable between two control targets for bi-fuel operation
- Manually switchable to open-loop operation
Diagnostics & I/O
- LED/alarm driver for diagnostic state indication
- Programmable diagnostics: min/max positions and O₂ sensor voltage
- Configurable fault and security settings
- 0–5 V output for shaft position indication
- Raise/lower and Target 1/Target 2 setpoint adjustment
- Bias input with programmable curve for feed-forward positioning
- LC-50 mixer sizes: 25, 30, 36, 43, and 50 mm
Applications
- Four-stroke gaseous-fueled engines (5–100 kW)
- Three-way catalytic converter emission reduction
- Stoichiometric engine applications
- Natural gas, LPG (propane), and bi-fuel operations
- Small power generation and pumping
Drake Controls Services
Drake Controls is a Woodward Authorized Distributor. We supply L-Series Air/Fuel Ratio Controls and LC-50 mixer assemblies, and provide configuration and repair.
