Class II LED Power Supplies with 277 VAC input

Posted on January 8, 2010 by

ARLINGTON HEIGHTS, ILLINOIS, USA, Friday, January 08, 2010: Hill Tech Sales, a leader in LED Components and Components for Electrical Power Conversion today posted information on 277VAC input rated LED Drivers for Class II outdoor lighting.

When using LED lighting in new installations LED drivers/LED power supplies with  standard universal input of 90 ~ 264VAC are not an issue since you can specify the specific voltage needed up front.

However, in many existing buildings that have dedicated electrical panels for lighting these are rated at 277VAC. In these installations LED lighting is typically not replacing all of the existing lighting. This means in these in cases in order to use these LED drivers you need a new circuit to supply 120VACVAC and a step down transformer to reduce the voltage from 277 to 120VAC.

New Class II LED Power Supplies are now coming on the market with wide ranging universal input of 90 – 277VAC which can be used on existing 277VAC lighting circuits with no voltage modification required.

Other features now standard on most LED Drivers are:

  • Highly Efficient Switching-Mode Technology
  • Active PFC (Power Factor Corrected)
  • Built For Outdoor Wet, Damp or Indoor Dry Applications
  • Silicone Encapsulated for Wet Locations (Use UL approved Water-Tight Conduit and Fittings)
  • Built-in EMI Filter for Low Noise
  • Rugged Rain-Proof Aluminum Extruded Case – IP65 Rated
  • Over-Current and Over-Voltage Protection with Auto-Recovery
  • Output Voltage Adjustable.

For adverse environments it also important to look for LED Drivers rated at 70°C at full load. Many LED Power supply de-rate to as little as 50% of rated power at 50°C.

For more questions on this article contact:

Vince Hill
LED Specialist
Hill Technical Sales
216 West Campus Drive
Arlington Heights, IL 60004   
Tel: +1- 847-255-4400  ext 12
Fax: +1-847-255-0192    

You may also visit: http://www.hilltech.com/

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8 Liquid Cooling Methods For High Power Energy Storage Devices

Posted on January 7, 2010 by

ARLINGTON HEIGHTS, ILLINOIS, USA, Thursday, January 07, 2010: Hill Tech Sales, a leader in components for Electrical Power Conversion and Thermal Management today posted information on 8 methods liquid cooling for energy storage.

Large scale solutions for energy storage present a new challenge regarding the heat produced and its effect on batteries and capacitors used for energy storage. The heat generated by the adjacent power components used in the inverter/converter often over shadows the losses created by charging and discharging batteries and capacitors.

In most cases great care is taken cool the switching devices and magnetic components however the batteries and capacitors are sometimes over looked yet they also are impacted by elevated temperatures in terms of degraded life and performance.

If liquid for cooling is available there are 8 key cold plate construction methods commonly used as a solution:

 Batteries and caps can be recessed into the plate to increase the conductive area and if needed additional thermal interface material is applied to increase thermal performance.

Sizes of these plates range from a few centimeters to slightly more than 2 meters.

An additional consideration is using a heat pipe assembly to remove heat from the internal structure of the capacitor or battery to the cold plate.

For more questions on this article contact:

Vince Hill
Thermal Specialist
Hill Technical Sales
216 West Campus Drive
Arlington Heights, IL 60004   
Tel: +1- 847-255-4400  ext 12
Fax: +1-847-255-0192    

You may also visit: http://www.hilltech.com/

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Ceramic composite resistors provide a reliable solution for Lithium-ion battery pre-charge circuits

Posted on November 30, 2009 by

ARLINGTON HEIGHTS, ILLINOIS, USA, Monday, November 30, 2009: Hill Tech Sales, a leader in components for Electrical Power Conversion today posted information on Lithium-ion battery pre-charge resistors.

Large scale Lithium-ion battery technologies present a new challenge regarding enormous inrush current requirements when used in Electrical Vehicle (EV) applications. Ceramic composite resistors provide a reliable high energy resistor solution for these pre-charge events.

Modern DC converters use input capacitors as part of their power converters’ topology.  When used with a Lithium-ion battery, huge inrush currents can occur as the capacitors are charged up to the battery voltage. The inrush becomes extremely difficult to handle when using large batteries with a low source resistance, and substantial capacitance values. Combined with little and/or no charge on the capacitors, inrush currents peaking over 1000 Amperes can easily occur.

A typical solution is to use a high energy resistor in a DC pre-charge circuit, to limit inrush current without limiting the operating current. Ceramic composite resistors are made for these applications. Unlike wire wound resistors or metal film resistors where only a metal conductor is absorbing the energy, the composite resistors’ entire mass is absorbing the energy yielding incredibly high impulse energy capacity. Reliability and robustness is also greatly increased since there is no “thin wire” acting as a conducting medium.

Typically a pre-charge resistor is used between a battery and the load to:

  • Prevent damaging the input capacitors.
  • Protect battery cells.
  • Stop the main fuse from blowing during the inrush current event.
  • Prevent damaging the contactors in the circuit.

Sizes of high energy resistors range from a few kilo-joules to mega-joules.

For more questions on this article contact:

Kurt Neuswanger
High Energy Resistor Specialist
Hill Technical Sales
216 West Campus Drive
Arlington Heights, IL 60004   
Tel: +1- 847-255-4400  ext 11
Fax: +1-847-255-0192    

You may also visit: http://www.hilltech.com/

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How to calculate input current required by a UV lamp ballast

Posted on October 22, 2009 by

ARLINGTON HIEIGHTS, ILLINOIS, USA, October 23, 2009: Hill Tech Sales, a leader in components for UV curing today introduced an article on how to calculate input current required by a UV lamp ballast

How do you calculate input current required by the ballast?

Input current to ballast = [(NOMINAL WATTS / Power Factor) * (Power supply efficiency)] / Ballast input voltage

 Example:

 For:

NOMINAL WATTS = 10,000

Power Factor = 0.92

Power supply efficiency) = 90%

Ballast input voltage = 220VAC

 Gives:

Input current to ballast = [( 10,000 / 0.92) * ( 0.90)] / 220 = 44.47 Amps

For more questions on this article contact:

Vince Hill
UV Specialist
Hill Technical Sales
216 West Campus Drive
Arlington Heights, IL 60004   
Tel: +1- 847-255-4400  ext 15
Fax: +1-847-255-0192    

You my also visit: http://www.hilltech.com/

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Ultra-Low Silicone Thermal Gap Filler Provides

Posted on October 21, 2009 by

ARLINGTON HIEIGHTS, ILLINOIS, USA, October 21, 2009: Hill Tech Sales, a leader in components for electrical power conversion and thermal management today is introducing ultra-low silicone gap fillers to its line of thermal interface materials.

Hill Technical has added new TP-S3LS ultra-low silicone gap fillers to its line of thermal interface materials. TP-S3LS pads contain less than 50 parts per million of silicone while providing 3.0 W/mK of thermal conductivity between hot components and their heat sinks. The gap filler’s minimal silicone content makes it suitable for use in silicone-sensitive applications including medical electronics, laser optics and telecommunications where silicone-based out gassing can lead to contamination and condensation issues or leave oily residues that interfere with process applications. The TP-S3 family of materials was developed by Chang Sung Corp. and is manufactured by Dongyun Electronics in South Korea.

Pads of TP-S3LS material are soft and compliant for easy compression and filling of air gaps between irregular mating surfaces. The material’s Shore 00 hardness is 55. TP-S3 pads can be used in temperatures up to 200°C, which exceeds the use range of silicone-free gap fillers. The material has a UL 94 flame class rating of V-0. Its dielectric breakdown voltage is over 5.0 kV.

New TP-S3 gap filler material is available in 210 x 297 mm (8.3 in x 11.7 in) sheets or die-cut parts. Standard sheet thicknesses range from 0.5 to 5.0 mm (0.020 in to 0.196 in).  Pricing for standard flat TP-S3LS sheets starts at $0.10 per square inch, which is below the cost of other 3.0 W/mK thermal gap fillers now available. Lower priced TP-S materials are also available with thermal conductivities of 2.0 and 1.0 W/mK.

For more information on all TP-S3LS ultra-low silicone gap filler materials, visit www.hilltech.com or contact:

Vince Hill
Thermal Account Manager
Hill Technical Sales
216 West Campus Drive
Arlington Heights, IL 60004    
Tel: +1- 847-255-4400  ext 15
Fax: +1-847-255-0192     

You my also visit: http://www.hilltech.com/

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