he ARRI M18 Hi-Speed Ballast is a key component of the ARRI M18 HMI lighting system, designed to power the lamphead with advanced features for professional film and video production. Here’s a general overview of its key information:

Primary Function
The ballast is an electronic power supply that operates with a variety of ARRI HMI lampheads, including the M18, M8, and True Blue D5 and D12. It’s specifically optimized for the 1800W HMI lamp used in the M18 fixture, but it can also power lamps ranging from 575W to 1800W.

Key Features
High-Speed Operation: The “Hi-Speed” designation refers to its ability to operate at high lamp frequencies (up to 1200 Hz). This is crucial for capturing flicker-free images, even with high-speed digital cameras shooting at frame rates of 1000 fps and beyond. This makes it ideal for special effects, commercials, sports, and other applications that require high frame rate photography.
AutoScan: This feature provides fully automatic control of the ballast’s frequency. It scans the lamp frequency to select and set the optimal frequency for stable, consistent light output, which is especially important for high-speed shooting.
Active Line Filter (ALF): ALF improves the ballast’s power factor, making it more efficient and less prone to fluctuations from the power supply. This ensures a consistent and stable light output.
Compensation of Cable Losses (CCL): This system automatically adjusts the power supplied to the lamp to compensate for electrical losses over long head-to-ballast cables. This ensures the lamp receives full power even when using cables up to 100 meters (328 ft) long.
DMX Control: The ballast supports DMX512, allowing for remote control of the fixture’s settings. Users can dim the light (50-100%), turn it on/off, and adjust the operating mode and frequency via a DMX system.
Multiple Operating Modes: The ballast offers various modes to suit different shooting scenarios, including:
High-Speed: For flicker-free high frame rate shooting.
Low Noise: For quiet operation in sound-sensitive environments.
Standard: A typical operating mode.
AutoScan: For automatic frequency optimization.
Automatic Lamp and Wattage Detection: The ballast can automatically detect the wattage and type of the connected lamphead, simplifying setup and ensuring proper operation.
General Specifications
Supported Wattages: 575W, 800W, 1200W, and 1800W.
Lamp Frequencies:
Low Noise: 50/60 Hz
Standard: 75 Hz
High Speed: 300 Hz (270-360 Hz range) and 1000 Hz (900-1200 Hz range)
Power Factor: cos φ 0.98
Dimming: 50-100%
DMX: 5-pin XLR input/output, 3 DMX channels.
Input Voltage: 90-130 VAC or 180-250 VAC.

The ARRI M18 Hi-Speed Ballast is a robust and sophisticated piece of equipment that provides filmmakers with a powerful and highly controllable lighting solution, particularly for scenarios that demand impeccable image quality at high frame rates.