Driver’s Vision Enhancer
At night and in degraded visibility conditions, drivers of armored vehicles need to see their surroundings clearly without having to leave the vehicle. This is achieved with driver's vision enhancers (DVE). These are thermal cameras mounted on the outside of the vehicle that transmit images to a monitor inside the vehicle.
These can be either single cameras or multiple cameras, which are often mounted on movable mounts in order to shift the field of view or automatically compensate for movements while driving.
The customer’s electrical specification for the power supply is as follows:
P-DUKE suggested a solution that not only met these requirements but also offered a wider input voltage range and different isolation barriers to avoid any interference between the powerful stepper motors and the imaging and stabilization system.
The MCF-028010-001 front-end filter and transient protection module protect the downstream DC/DC converter against the transient voltages of the 28V DC grid in the vehicle, defined in MIL-STD-1275E:
It also has an integrated EMI filter meeting MIL-STD-461G and limits the inrush current to 5A, protecting the 28V DC grid, fuses, and connectors against high currents during switch-on. Reverse polarity, overtemperature, short circuit, and overvoltage protection circuits make sure that the module is not damaged by incorrect use or connection.
With a maximum output current of 10A, it can provide enough power over the full operating range of the system.
For the downstream supply voltages, two isolated DC/DC converters are used. The QAE100-36S24U is a 100W converter with 9 – 75V input and 24V/100W output and provides the necessary drive voltage for the positioning stepper motors. It can deliver full power when the grid voltage drops to 16V or lower during cranking of the engine or at initial startup.
Although at first glance isolation would not appear to be absolutely necessary, an isolated converter was chosen in order to prevent interference between the high, pulsed motor currents and the highly sensitive signals from the camera and sensors.
A further separation of these signals is achieved by using P-Duke’s isolated FKC08-24S05W converter to generate the 5V supply for the camera.
And finally, the ESR01-12S3P3, a 1A non-isolated converter in the standard LM78 package, provides the 3.3V supply for position and movement sensors and stabilization circuitry.
This solution is mechanically robust and easy to cool. The front end and the 100 W converter modules are packaged in a quarter-brick form factor with baseplate cooling and can be mounted to a heat sink.
All modules, including the FKC08-24S05W and the ESR01-12S3P3, are qualified for MIL-STD-810F, which means that they can withstand the high thermal and mechanical shock and vibration requirements for ground vehicles.
Block diagram:
Products:
MCF-028: Military-grade EMI filter and transient protection modules for 24V systems. Meeting MIL-STD-1275E, 704F, and 461G standards, the MCF-028 series offers active surge protection and noise suppression, safeguarding power electronics in critical defense environments.
QAE100U: 100W quarter-brick railway DC/DC converters featuring an ultra-wide 12:1 input range (14-160VDC). Certified to EN50155 and EN45545-2 with 3000VAC reinforced insulation, this series ensures robust performance and safety in demanding railway systems.
FKC08W: 8W railway-certified DC/DC converters in DIP24 or SMD packages. With a 4:1 input range and EN50155 compliance, the FKC08W series features 1600VDC isolation and an optional -55°C operating capability, perfect for rugged industrial and transport applications.
ESR01: High-efficiency non-isolated switching regulators delivering up to 96% efficiency without heatsinks. With a wide input range and compact SIP3 design, the ESR01 series provides reliable power for space-constrained automation and industrial applications.
