The Powerstat LW-136-DP57577 (LW136B Series) is a single-phase, manually operated variable autotransformer for precise AC voltage control from zero to line voltage. This device delivers continuously adjustable output with linear response, negligible waveform distortion, and high efficiency—making it ideal for voltage correction, equipment testing, and applications requiring variable power input across industrial and laboratory environments.
Technical Specifications
• Series: LW136B
• Type: Manually Operated Variable Autotransformer, Single Phase
• Input Voltage: Selectable 120 V AC or 240 V AC via dual primary windings (series/parallel configuration)
• Frequency Range: 50 Hz to 2000 Hz
• Output Voltage: 0 V to line voltage, continuously adjustable
– Standard configuration: 0–30 V AC at 25 A (constant impedance)
– Center-tapped configuration: 15–0–15 V AC at 35 A (constant impedance)
• Maximum Output Current:
– Constant impedance load: 28 A at line voltage
– Constant current load: 22 A
– LW136BU variant: 35 A maximum
• KVA Rating: 0.75 kVA
• Commutator Surface: Precious metal plating for overload tolerance, stable contact drop, and corrosion resistance
• Coil Technology: PowerKOTE® coils (136B–236B series)
– Key Features
• Linear output voltage proportional to brush-tap rotation angle over full range
• Brush-tap maintains continuous contact with multiple winding turns for sub-volt adjustment resolution
• Voltage drop scales with applied load
• Derating required for operation above rated frequency or elevated ambient temperature
• Low watt loss compared to resistive control methods
• Output waveform faithful reproduction of input signal
– Typical Applications
• Equipment voltage conditioning and correction
• Laboratory testing requiring variable AC input
• Industrial applications demanding smooth, stepless voltage adjustment
• Systems requiring dual input voltage flexibility (120 V / 240 V selection)
– Compatibility & Integration
Dual input primary windings support connection to either 120 V or 240 V AC supply lines. Secondary winding configurations accommodate both single and center-tapped output requirements, enabling standard or ±15 V operation modes.
