Tuesday, July 31, 2012

A Promotion!

Congratulations to Daniel Deschenes, he has officially transitioned into Sales.  He's VMI's newest Sales Engineer. 

He's been with VMI for over seven years and he's a technical guy, so he knows a lot about VMI products and manufacturing processes.  Now that he's officially in Sales, you can expect to see him out and about visiting customers, attending trade shows, and juggling in his free time.

Feel free to give him a call (559.651.1402) or send him an email if you have any technical questions about high voltage diodes, opto-couplers, rectifiers, power supplies, or any and all VMI products.

Monday, July 30, 2012

Website Launch

VMI's website has a new look.  Check it out.  The logo has changed, and the main graphic is reflective of our products.  We'll be fine tuning it over the next few weeks, so if you come across a glitch, or inconsistency, please email me at K. Holland.  Feedback is welcome!  

Product photos, bottom l-r, formed lead high voltage diode, optodiode, optocoupler, CRT type power supply, X-ray tube type power supply

Wednesday, July 11, 2012

High Voltage Multipliers - MVM and PVM302P12

Why has the MVM series been replaced by the PVM series of high voltage hybrid multipliers?

High Voltage Hybrid Multiplier
PVM302P12 high voltage multiplier
 To be perfectly honest, the MVM series has been replaced by the PVM series because of low profitability.

The lack of profitability is a complex question, and there are no easy answers. Factors such as volume pricing (or lack of), process variations, data collection, and marketing, all contribute to whether a product is profitable or not.

In the case of the MVM, one of the largest issues was purchasing raw materials in low quantities. Take the following hypothetical situation. Say the MVM uses two lead frames per device, and they cost $5 each. The lead frame manufacturer has a minimum buy of 10,000 units per lead frame. If the device sells for $15, already 67% of the selling price is tied up in two components. You can see where this is going, yes?  This could be a problem when the device actually contains many more components.

Looking at it from a different point of view, say the total material costs, including the two lead frames, come to $15.00. Then, using the formula I use when I take my car to the mechanics to figure out how much it’s going to cost me to get my car fixed, which is to double the cost of the parts – then materials and labor for the MVM would come to $30.00. This is twice the original selling price. How many MVMs do you think we’d sell at that price? Exactly. The concern is we’ve priced ourselves right out of the market. Plus, to add insult to injury, if we build one part, we’re sitting on raw material inventory of $100,000 in lead frames alone. Even if we build 500 parts, lead frame inventory costs are still $95,000.

The moral of the story is that its a delicate balancing act between pricing, profitability, reliability, and manufacturability. In an ideal world, there would be no minimums, no set-up charges, no late deliveries, and 100% yield.  (Wouldn't that be great?!)

On the other hand, if that were the case, then a lot of us would be out of a job.  (Sigh)

Oh, by the way, the PVM family does not use lead frames.

Tuesday, July 3, 2012

High Voltage Diodes in High Voltage Multipliers

The illustration below shows a six stage, series, half-wave multiplier. This is a fairly simple design that utilizes high voltage diodes and high voltage capacitors.

Six-stage High Voltage Multiplier

The diodes are axial-leaded, glass bodied; the capacitors are coated-and-leaded, single layer ceramic. The end product is encapsulated, so all you’d see is a ‘black box’ with leads, or some type of terminations, coming out of it.

Typical applications include CRT type displays used in cockpits, and even the old-fashioned analog oscilloscopes (remember those?). They work well in instrumentation because low levels of noise and excellent regulation are achievable.

The nice thing about these multipliers is they are not limited to just caps and diodes, but can include feedback resistors, filter networks, multiple outputs, voltage taps, and more.

Many different topologies are possible besides the more common Cockcroft-Walton multiplier. Full-wave multipliers, parallel multipliers, or combinations of the above are all possible.

Custom features include ripple and regulation voltages, physical dimensions, terminations.

Give us your input voltage and output voltage, and we’ll do the rest.