Advances in digital signal processing have led to more flexible power converters that can be programmed to meet the precise requirements of marine electronics. Power converters such as inverters, battery chargers and power supplies are often installed to convert available direct or alternating current to the appropriate power outputs required.
The power source on a vessel can vary, such as AC from generators or shore power and DC in varying voltages from battery banks. Voltage and frequency of outputs can also vary for each piece of equipment, which means customised solutions are required.
According to Canada-headquartered Analytic Systems, digital signal processing (DSP) technology has simplified the process of controlling power. DSP-based models can be programmed to accommodate a range of input and output parameters, such as varying AC power standards, customised 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.
Regardless of the type of converter or electronics powered, the new breed of intelligent power converters have the flexibility and ease of programming that allows system designers and installers to choose from a simplified selection of models that can be customised to meet the precise needs of marine electronics. This eliminates the need for application-specific designs and enables faster delivery of the power converter. They could be used for: instrumentation, radios, satellite phones, infrared cameras, echo sounders, emergency signal devices and radar.
While some electronics are connected to the existing DC battery system on some vessels, more sensitive, microprocessor-based equipment often requires a dedicated power supply or voltage converter to operate. Vessels often have AC-powered equipment on board that requires DC-AC inverters, such as a laptop computer or phone rechargers. Another type of power converter would also be required if vessels are linked to AC shore power.
Digital converters for night vision cameras
In the case of sophisticated infrared camera systems, a digital converter with programmable safety settings plays a key role in protecting the equipment from malfunction or damage caused by spikes or fluctuations in voltage.
According to Night Vision Technology Solutions (NVTS)’s chief executive Joe Janson, thermal cameras are particularly at risk, because they must remain within specific voltage range parameters. He added: “If there is a large spike in voltage, it could damage a camera that can cost hundreds of thousands of dollars. So, a consistent voltage needs to be maintained.”
NVTS’ fixed and portable night vision cameras are used for navigation, search and rescue, coastal surveillance, man overboard, and object identification tracking. Marine infrared camera systems are typically installed on tugs, quick response vessels, large patrol boats, 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 high definition video and thermal images for surveillance and security. The power supplies are from Analytic Systems, which has developed intelligent digital power converters and Power Wizard software. NVTS uses these products to define the output frequency, output voltage, frequency and voltage shutdown parameters of any converter from a laptop with a standard memory stick interface.
"We like these power supplies because we can fine-tune the power supply to fit the specific needs of each application,” said Mr Janson. In one recent example, the flexibility of the power supply allowed the infrared camera to be used on a vessel located in South East Asia where the AC power source is 220V. A built-in autosensing capability allows the intelligent power supply to handle universal voltages.
Mr Janson said another appeal of the converter is that it produces a pure sine wave for cleaner utility-grade power rather 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 uses the powerful monitoring and reporting capabilities available from digital signal processing models to accommodate for voltage drops along longer cable runs that, in some cases, can extend more than 100m 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 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 that out and match it,” said Mr Janson. “With the digital interface, we are able to physically monitor the actual output of the power supply using the appropriate length of cable.”
Regardless of the requirement, intelligent digital signal processing can improve the power supply to various types of marine electronics. Future developments in processing and software should enable even more applications.