The constant-current PRM™ demonstration board provides precisely-regulated currents for direct-drive multi-LED applications which control LED intensity and brightness by current regulation. The board can be used as a standalone module to provide an adjustable non-isolated current up to 240 W (5 A at 48 V), or can be combined with a V.I.Chip voltage transformation module (VTM™) to provide an adjustable, isolated current up to 100 A. Using less than 1 W for every 1000 Lumens generated by the LEDs, the PRM+VTM combination can be used with BCM™ bus converters and low voltage driver ICs in lower power applications such as LED TV backlighting.

The new evaluation board demonstrates the high power density of the PRM, with current accuracy of 99.7% across the load range. Kelvin connections allow the efficiency of the V.I Chip™ components to be measured independently of load connect losses. Oscilloscope probe jacks are available to measure the output voltage, including output voltage ripple, and the board has fused PRM inputs as well as system enable and disable. There is also the option to mount a V.I Chip push-pin heat-sink.

For information on the PRM™ evaluation board CLICK HERE

MAXI MIL-COTS DC-DC converters

A new family of MAXI MIL-COTS DC-DC converters allows designers to specify one converter for 12V and 24V vehicle battery systems. The 28V DC-DC Maxi converters feature a wide input range of 10V to 36V with eight different output voltage options and maximum power of 200W. Full encapsulation, using Vicor’s proprietary spin-fill process, ensures void-free encapsulation which protects the modules even in harsh environmental conditions.

For more on MIL-COTS DC-DC converters CLICK HERE

Major new range of 72V DC-DC converters

Vicor has just launched a major new range of 72V input DC-DC converters for rail and transport applications. Joining their proven 110V modules, the new range introduces the rail industry’s widest choice of DC-DC converters.

The new 72V input range features 27 DC-DC converters covering nine standard output voltages over three standard package sizes and three pin options. Power outputs range from 75W up to 400W. The modules meet EN50155 requirements for operating voltage, shock, vibration and temperature, whilst the product platform simplifies thermal management with three proven baseplate designs. The range covers five different environmental grades, with optional RoHS compliance.

For more on new 72V DC-DC converters CLICK HERE

Faced with designing a power circuit for a solar-powered car, to compete in the Solar Challenge across 1,800 miles of Australian desert, a team of young engineers turned to Vicor DC-DC converters. Their challenge was to provide stable and reliable supply voltage to the on-board PC and telemetry equipment, despite hot desert conditions, and severe restrictions on energy, weight and heat dissipation options. In addition, the DC-DC converter would need to handle parallel connection to a motor, drawing high peak currents, which would over-ride the 110V input voltage when the car was being driven.

The design team chose a Vicor V1-2T3-EV DC-DC converter with a 110 V input, 24 V output and a 150 W power rating, to provide power on the low-voltage circuit. This module offered a fast and straight-forward design coupled with sufficient reserve capacity to ensure stable and reliable operation under all conceivable conditions. Its consistently high operating efficiency also meant that it did not require a heat-sink, even in the Australian desert. A smoothing capacitor on the input was all that was needed to handle the peak currents caused by the motor and control circuits. Two other discrete converters were used to generate the 12 V and 5 V supplies for battery monitoring, measurement controller and Bluetooth data transmissions.

An offline battery charger, based on a Vicor DC-DC converter module and controller IC, provides the flexibility to adapt the design for every input voltage range, battery voltage, and capacity. The design also achieves high efficiency as well as a compact footprint.

With a controller IC optimising the charging process of lead-acid batteries, and Vicor’s high power-density DC-DC converter modules, the design achieves high reliability, with reduced volume and lower power dissipation.

An efficient converter control circuit uses two features found on all Vicor Maxi, Mini, Micro converters: the Secondary Control (SC) pin on the output, and the internal configuration of the +Sense and +Out pins. These allow the output voltage to be varied so that, when it is trimmed down to the minimum voltage, the control voltage can be used to vary the output voltage (see Figure 1).

The designs maximises battery operating life and minimise the cost of maintaining large battery banks, such as those for UPS systems or electric vehicles whilst providing the flexibility to adapt the charger across different applications.

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