MAKARAND SM 781-6-60MD Motorised Potentiometer

OverviewMAKARAND SM 781-6-60MD is a marine-grade motorised potentiometer manufactured by Makarand Electronics, India. It is widely used as a remote setpoint unit for generator governor control, engine speed regulation and analogue control loops onboard vessels. This unit converts electrical control commands into precise variable resistance output, with a rotation range of 0–90°. It accepts 24VDC supply and features a 500Ω resistance element rated at 3W. The rugged metal enclosure is built to withstand vibration, humidity and unstable power conditions typical of marine engine control rooms. It supports both manual local adjustment via front knob and remote motorised drive, which makes it suitable for auto/manual transfer in speed control systems. This model is largely discontinued and mainly circulated as second-hand spare for legacy marine automation and genset control panels.

FeaturesMAKARAND SM 781-6-60MD integrates a small drive motor and precision wire-wound potentiometer inside a heavy-duty metal housing. The Motorised Potentiometer provides stable 500Ω variable resistance output for analogue reference signals. It has dual operation modes: local manual adjustment on the front dial and remote motorised positioning by control contact signals. The terminal strip design facilitates wiring with governor controllers, load sharing units and engine control systems. It is resistant to shock and vibration, complying with marine environmental requirements. Front dial with scale marking allows operators to read setpoint position directly. MAKARAND SM 781-6-60MD is commonly matched with DEIF, Woodward and other marine governor systems for speed setpoint control.

SpecsMAKARAND SM 781-6-60MD motorised potentiometer. The Motorised Potentiometer part number: SM 781-6-60MD. Supply: 24VDC. Resistance value: 500Ω, 3W. Rotation angle: 0–90°. Operation: motor remote drive + manual knob adjustment. Termination: screw terminal block. Enclosure: metal casing. Origin: India. Weight: approx 2.2kg. Lifecycle: discontinued, used spare stock. It is stocked as genset speed setpoint control spare.

Operating ParametersMAKARAND SM 781-6-60MD ambient operating temperature: -10℃ ~ +55℃. The Motorised Potentiometer relative humidity: 5%~95% non-condensing. EMC: comply with marine control IEC standards.

PrincipleMAKARAND SM 781-6-60MD receives forward/reverse drive signals to activate the internal motor. The Motorised Potentiometer drives the wiper of the wire-wound resistor to change the output resistance value, sending the resistance signal to the governor as speed setpoint reference. Operators can also turn the front knob manually to adjust the setpoint when remote auto mode is disabled. Wear of resistance winding, motor burnout or wiper contact degradation will cause MAKARAND SM 781-6-60MD output drift or loss of setpoint control.

ApplicationsMAKARAND SM 781-6-60MD is widely deployed in cargo ship engine control panels, generator governor cabinets, offshore platform power control systems and legacy marine automation consoles. The Motorised Potentiometer undertakes remote speed setpoint adjustment for diesel generators, and works with governors, load sharing modules and alarm systems to form generator speed control loops. MAKARAND SM 781-6-60MD is a preferred spare for old marine genset speed control retrofit and maintenance.