'Intelligent' power converters provide flexibility

To operate marine electronics and communication devices, power converters such as inverters, battery chargers and power supplies are often installed to convert available DC or AC to the appropriate power outputs required.

Complicating matters, both the power source (DC in varying voltages from battery banks and AC from generators or shore power) and the outputs (voltage, frequency, etc.) can vary for each piece of equipment. So much so, that finding the ideal converter can be difficult and often requires a customised solution.

Fortunately, digital signal processing (DSP) technology has significantly simplified the process. Unlike analogue converters, which require board-level component modifications to alter function or features, DSP-based models can be programmed to accommodate a range of input and output parameters.

By doing so, digital converters can be programmed to accommodate varying international AC power standards, market-preferred or custom battery voltage input/outputs and a multitude of safety settings. These adjustments, and even firmware updates for the unit itself, can be made at any point in the product’s lifecycle, even after installation.

This is allowing system designers and installers to choose from a simplified selection of models that can essentially be customised to meet the precise needs of each application.

Marine electronics
Marine electronics and communication systems run the gamut from operational, such as instrumentation, lighting, radios, satellite phones, infrared cameras, fish finders, depth sounders, emergency signaling devices, and radar, to entertainment system devices like satellite television, DVD players or iPod or MP3-compatible music players.

While most are connected to the existing DC battery system, more sensitive, microprocessor-based equipment often requires a dedicated power supply or voltage converter to operate.

Vessels also may have AC-powered equipment on board that requires DC/AC inverters, such as a laptop computer or cell phone recharger. Another type of power converter, a battery charger, is used to top off batteries when connected to AC shore power.

In the case of sophisticated infrared camera systems, a digital converter with programmable safety settings also plays a key role in protecting the equipment from malfunction or damage caused by spikes or fluctuations in voltage.

“Thermal cameras are particularly at risk, because they must remain within specific voltage range parameters to operate properly,” says Joe Janson, CEO of Night Vision Technology Solutions (NVTS). “If there is a large spike in voltage, it could even damage a camera that can cost hundreds of thousands of dollars. So you need to maintain a proper, consistent voltage to it.”

NVTS manufactures fixed and portable night vision camera systems used for navigation, search and rescue, coastal surveillance, man overboard, and object identification tracking. These marine infrared camera systems are typically installed on small, quick response vessels, large patrol boats, tugs, fast frigates and yachts.

To protect its systems, NVTS supplies a digital power supply with each of its Nimbus IPX night vision camera systems. The IP-based camera system captures both 1080P HD video and thermal images for surveillance and security.

The power supplies utilised by NVTS are from Analytic Systems, an innovative Canadian manufacturer of battery chargers, voltage converters, inverters, power supplies, and frequency converters and MPPT solar charge controllers. Founded in 1976, the company was the first to develop high frequency switching voltage converters for the marine industry.

Although the company still offers analogue converters, the emphasis and focus has been on its new “intelligent” digital offerings. By using its free “Power Wizard” software, companies such as NVTS are able to define the output frequency, output voltage, output frequency and low voltage shutdown parameters of any converter from a laptop with a standard micro-USB interface.

“We like these power supplies because we can fine-tune the power supply to fit the specific needs of each application,” says Janson.

In one specific recent example, the flexibility of the power supply allowed the infrared camera to be used on a vessel located in Southeast Asia where the AC power source is 220VAC. A built-in auto-sensing capability allows the intelligent power supply to handle universal voltages.

Another appeal of the converter, says Janson, is that it produces a pure sine wave for cleaner utility-grade power than cheaper, quasi sine wave alternatives. Pure sine wave inverters are ideal when operating sensitive electronic devices that require a high quality waveform with little harmonic distortion.

NVTS also utilises the powerful monitoring and reporting capabilities available from DSP-based models to accommodate for voltage drops along longer cable runs that, in some cases, can extend a hundred feet or more and involve several power supplies.

In these cases, the company attaches the cameras and digital power supplies with cabling of equivalent length, and then adjusts the settings to adjust for the inevitable voltage drops prior to delivery of the system.

“Each time we get a power supply, we hook it up to the camera before we ship it and actually match it,” says Janson. “With the digital interface, we are able to physically monitor the actual output of the power supply using the appropriate length of cable.”

Given that NVTS’ products are often utilised by the Coast Guard, Navy and the Department of Homeland Security, its products are controlled under the International Traffic in Arms Regulations (ITAR). As a Controlled Goods Certified facility, Analytic Systems also meets those requirements.

Regardless of the type of converter or electronics powered, this new breed of intelligent power converters and the flexibility and ease of programming will allow engineers to select from a simplified list of models and essentially receive a custom solution.This not only eliminates the need for application-specific designs, but also enables faster delivery of the power converter at a more economical cost.