Westcor provides flexible, powerful AC-DC solutions

Vicor's Westcor division specializes in the manufacture of flexible and high quality medium to high power AC-DC supplies based on the proven design and performance of Vicor's DC-DC converters. Our MegaPAC, LoPAC and FlatPAC-EN families of power solutions are highly configurable and can provide literally thousands of custom output combinations where voltages may be specified in 1/10th increments between 2V - 400V (voltages greater than 95V are available through series arrays).

Westcor's "your custom is a standard" modular product architecture enables our power solutions to provide the specific outputs you need with up to 20 different isolated voltages from a single unit. Your custom prototype can be available in as little as two weeks, delivering a robust, high performance power supply, as well as reduced time-to-market. Low noise options are also available with ripple as low as 10mV or 0.15% peak to peak.

High performance and flexibility means that Westcor has the right solution for your application.

Westcor also recently introduced the "Vantage Line" family of power supplies. Offering a 15% price reduction with all the speed-to-market and performance of our standard supplies, the Vantage line is ideal for customers with relaxed environmental and operational specifications.

Need a power supply now? Configure your own Standard or Vantage solution right now by visiting Vicor's VSPOC™.

New series of 110V input module for railway application

A new series of 110V input module is now available. Featured with a wide input range from 66 to 154V, these modules offering includes eight standard output voltages (3.3, 5, 12, 15, 24, 28, 36, 48 V) in combination with three different package sizes, with output power ranging from 50W up to 400W. Encapsulated circuitry for shock and vibration, the modules are designed for railway and transportation system which values product robustness and reliability, applications including communication systems, information displays, lighting, control systems, ticket machines, passenger entertainment, public address systems, and power generation systems.

Performance specifications include a wide input voltage range in accordance with EN50155 as well as efficiencies ranging up to 90% for the higher output voltages. The models are available in five different environmental grades, with six different pin options and three base plate styles. Customer can also configure any input, output and mechanical combination using Vicor's patented intelligent design system - PowerBench™, and verify them in real time.

QPI Active Input Filter ideal solution to telecom blade & COTS applications

Full size QPI models are 1.0" x 1.0" x 1.0" (25 x 25 x 25 mm) SiP, with LGA mounting. QPI-11 and QPI-12 are half sized. Efficiency up to 99% at full load.

P/N (Z=RoHS)	Input Voltage	Current Rating	CM Attenuation @ 250kHz	DM Attenuation @ 250kHz	Hot Swap
QPI-3L (Z)	24/28Vdc	7A	60dB	80dB	N/A
QPI-4L (Z)	48/60Vdc	7A	40dB	70dB	N/A
QPI-5L (Z)	24/28Vdc	14A	60dB	80dB	N/A
QPI-6L (Z)	48/60Vdc	14A	40dB	80dB	N/A
QPI-7L (Z)	24/28Vdc	6A	50dB	80dB	Yes
QPI-8L (Z)	48/60Vdc	6A	40dB	70dB	Yes
QPI-9L (Z)	24/28Vdc	6A	65dB	80dB	N/A
QPI-10L (Z)	48/60Vdc	6A	45dB	70dB	N/A
QPI-11L (Z)	24/28Vdc	7A*	65dB	80dB	Yes
QPI-12L (Z)	48/60Vdc	7A*	45dB	70dB	Yes

      QPI-9L, QPI-10L, QPI-11L and QPI-12L are V•I Chips specific Models
      * Parallelable for up to 14A

      QPI evaluation boards available.

Meeting High Energy Surge in 110V Input Railway Applications

RIA12, "General Specification for Protection of Traction and Rolling Stock Equipment from Transients and Surge in DC Control Systems" developed by the Railway Industries Assoication (RIA) specifies that equipment must withstand a 20ms overvoltage surge 3.5 times greater than the nominal 110V input voltage. That is the surge voltage is 385V for 20ms duration. The source impedance of the overvoltage pulse is 0.2. That would mean a clamping device clamps the surge to 160V would need to dissipate up to 3600 J energy while typical common transient suppression devices (TVS) are expected to handle several joules of energy only. So what's the solution? It would be an active circuit using series pass power device that a proper MOSFET would be the light of answer.

An example of the active clamp circuit is shown in the figure below. When overvoltage occurs, it triggers D2 to conduct, turning Q2 ON and the gate voltage of Q1 is then clamped at about D3 voltage. The output voltage equals the clamping voltage minus the gate source voltage of Q1, thus protecting the downstream DC-DC converter.

During normal operating, all components except Q1, R2, the 470pF capacitor and the two 1N4148 diodes appear as if they are not there. It is simple here to have Q1 at its fully saturated low dissipation state using gate-out signal from the downstream DC-DC converter to drive the charge pump circuit formed by the two 1N4148 diodes and the 470pF capacitor. Vicor's VI-200/J00 DC-DC converters and in particular the 110V input modules (part number designated with a letter "T") would be the match to this active clamp circuit.

For a complete description of the circuit, see Vicor's application note Using Modular DC-DC Converters to Meet European Standards for Railway Applications. The app note also addresses fast transients and input specifications defined by EN50155 in railway applications.

Halogen Headlight Lamp for Train

Vicor Maxi modules (V110A28T400BL, 110V input, 28V 400W output ) are used to redesign the power supply for Halogen Headlight lamp of the train. Using the new V110 Maxi module, Vicor modules are very well suited to the Rolling Stock application.

Vicor modules were suitable for this project because of the wide input voltage range: 66-154 Vdc. The low storage and operating temperatures were also of benefit to the client; the baseplate can be put onto a cold surface to make the design easier. Also, because the modules are fully encapsulated, they withstand high shock and vibration environments (conform to EN50155 shock and vibration requirements).

LED / LCD Display Panel for Railways on Board

When using a train look at the new LED/LCD display panel on board. Installed in each compartment this sign carries various kinds of information including destination, next stop, news and weather forecast clearly and in an intelligible form.

Vicor "T" input modules (Vin 66-160VDC, VI-200 and VI-J00 products) are used in this system. With a high reliability (MTBF), low size and weight, and ease of use, the Vicor modules provided the ideal solution.

If you have used Vicor modules in a novel application, we'd love to hear from you!

Vicor Railway Brochure -
Vicor offers component power solutions that are ideally for the rail industry. Nowadays, our products are used in almost every Asian and European rail network.

Vicor Military COTS Products -
A new piece of Military literature is now available which you can find some successful record of supporting the most demanding applications inside the catalog.

Lean Manufacturing

Vicor's production facility in Andover, Massachusetts has focused on what is called "Lean" or "Continuous Flow" manufacturing over the last several years. This can best be described as eliminating various wastes, such as motion, excess inventories, non-value added processes, etc., as well as focusing on the speed of workflow through the factory. It has been proven that as cycle time decreases, quality and cost improve.

Seven years ago, the average cycle time for a Vicor brick was about 500 hours. Today, with the new procedures a commercial unit is built in about 50 hours. In addition to our improvement in efficiencies, this has significantly impacted on-time delivery and responsiveness.

In the first quarter of 2007 we have completed the project for Maxi, Mini and Micro products that bringing us more improvement. Vicor's 'mass customisation' production processes are done on a build-to-order basis - that is, we only start work after receipt of a customer order. This is a must, given the approximate 7,000 different models we ship a year and the difficulty of forecasting so many items. We will soon begin stocking common electrical building blocks, then doing our final assembly and test on a build-to-order basis. We believe that this could bring our cycle time down by a factor of eight, which could potentially enable us to build and ship sample quantities within 24 hours of receipt of an order. Production quantities could have lead times of as little as a few weeks. We are currently implementing plans to match this performance for VI-200 / VI-J00 products as well.

In this process of Lean manufacturing, we have freed up about 15,000 square feet of manufacturing space, leaving us well poised for future growth.

To learn more about Vicor Quality Systems, you can go to our Quality Centre. Here you can create a custom quality report or take a 'virtual tour' of Vicor's 21,400sq meter factory, showing the key stages in the manufacture of our products. There is a library of documentations, videos, and process charts, downloadable reports in PDF format, with hyperlinks to other information that satisfy the individual's Quality needs. Alternatively, you can request a Vicor Factory Tour CD.

Johnny Yuen, who has been with Vicor since early 1998 as Applications Engineer. Prior to joining us, Johnny was employed at MEMEC Corp. as a Field Applications Engineer of Power division, and he worked as Product Safety Engineer & Power module Product Design Engineer at Astec Power Systems after his university life for 2.5 years. And now, he is our Senior Applications Engineer with dedicated responsibilities in PRC & Taiwan, and other South-East Asia countries such Thailand, Philippines. Johnny graduated from The Chinese University of Hong Kong with B. (Honor) of Electronics Engineering in 1995.

Johnny lives with his lovely wife & his Little Cutie Boss, Jerry, in Hong Kong. He was one of the representative player of Hong Kong universities for The World University Badminton Championship held in France in 1996; he still enjoys playing badminton even now but unfortunately seldom join the competitions now.

Describing BatMod Operating

Some operating points (lines) labeled a, b, c, d, e, f in the 12V output BatMod operating area

Descriptions:
1. Constant current mode, Ru > 0 ohms and is finite; Rd > 0 ohms and is infinite.
2. Constant voltage mode, Ru > 0 ohms and is finite; Rd > 0 ohms and is infinite.
3. Constant voltage mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is finite.
4. Constant current mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is finite.
5. Constant current mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is infinite.
6. Constant voltage mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is infinite.
7. Constant voltage mode, Ru is OPEN; Rd is OPEN.
8. Constant current mode, Ru is SHORTED; Rd is SHORTED.
9. Constant current mode, Ru is OPEN; Rd is SHORTED.
10.Constant voltage mode, Ru is SHORTED; Rd is OPEN.

Match the symbols a, b, c, d, e, f shown in the graphs above to the 1-10 descriptions for making the best sense. Mark symbol "X" to an improper description if any, and email your answers to vicorhk@vicr.com with 'Quiz7' as the subject no later than July 1st. All entrants submitting the correct answers will be entered into a prize draw to win one of 25 USB sticks*.

Hints: Each symbol could have multiple valid descriptions. Try using Vicor online calculator to help you IF you are in doubt.

Good Luck!

* The Quiz is NOT open to Vicor employees or distributors.