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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Step by step procedure for UV Lamp Replacement in UV Reflector Assemblies

Posted on October 19, 2009 by

ARLINGTON HIEIGHTS, ILLINOIS, USA, October 20, 2009: Hill Tech Sales, a leader in components and subassemblies for UV curing today published a “step by step procedure for UV Lamp Replacement in Reflector Assemblies

This procedure can be seen in detail in the FAQ section of the Hill Technical Website, below are steps listed:

  1. A qualified person following proper lockout procedures must perform lamp replacement.
  2. Turn power off. Be sure that the irradiator and lamp have cooled before removing the lamp.
  3. Disconnect all power and high voltage cable from the LIA.
  4. Remove irradiator cover by removing both knobs at each end of the LIA and lifting out the assembly by its handles.
  5. Place the LIA upside down on its handles
  6. Remove one metal diffuser. Loosen the screws on the lamp holder to release the top bracket.
  7. Disconnect the lamp leads and pull lamp out of the LIA.
  8. Clean the replacement UV lamp and reflector liners with a lint free cloth and denatured isopropyl alcohol. Use latex or vinyl gloves during this step to keep the lamp free of any fingerprints.
  9. Place one lamp lead and end fitting through the mounted metal air diffuser and on top of the lamp holder.   Place the loose metal air diffuser around the other lamp end and place the lamp end onto the lamp holder.

10.  Remount the metal air diffuser and place the top bracket over the lamp end and tighten the top bracket.

11.  Connect lamp leads to ceramic standoffs.

12.  Place the irradiator back in place and tighten the four knobs and reconnect the high voltage cable by matching index to index and screwing the connector cable down completely.

For more information, contact:

Vince Hill
UV Component 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 my also visit: http://www.hilltech.com/

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Ultra miniature, cost effective, 1 watt DC/DC converters

Posted on October 19, 2009 by

ARLINGTON HIEIGHTS, ILLINOIS, USA, October 16, 2009: Hill Tech Sales, a leader in components for electrical power conversion today is introducing Ultra miniature, cost effective, 1 watt DC/DC converters.

These 1 watt products feature continuous output short circuit protection – a critical safety feature that protects the load circuit and the converter from dangerously high current levels in ultra miniature packages:

AM1DR-RZ (SIP7: 19.50 x 7.20 x 9.50mm) and AM1MR-Z (DIP14: 20.30 x 10.16 x 6.90mm) operate at the most commonly designed fixed inputs of 5, 12, and 24VDC (with ±10% tolerance).

 Highly regulated and protected output voltages 3.3, 5, 7.2, 9.12, 15VDC feature a tight load regulation of ±0.5% to ensure that stable voltages are delivered throughout the operating range, under all types loading conditions.

 Each of the 18 models in the AM1DR-RZ and AM1MR-Z series feature input/output isolation of 1000VDC, allowing these versatile power supplies to be configured for reverse polarity on the output or to be wired in series to create higher output voltages.

 Operating within an industrial temperature of -40°C to +85°C without derating, both the AM1DR-RZ and AM1MR-Z series are engineered to meet the IEC 60950-1 standard for use with indoor or outdoor telecommunication networks or cable distribution systems.   The components MTBF of greater than 1,500,000 hours further supports their use in applications where access for maintenance is limited or restricted. 

 RoHS compliant, all models undergo 100% production testing of their parameters to ensure the high reliability, while remaining competitively priced 

For more information, contact:

Alena Kamin
Customer Service Manager
Hill Technical Sales
216 West Campus Drive
Arlington Heights, IL 60004    
Tel: +1- 847-255-4400  ext 13
Fax: +1-847-255-0192     

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

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