CUI Inc Expands V-Infinity Power Line

TUALATIN, OR – CUI Inc’s power line, V-Infinity, announced the addition of 10 and 15 W models to their VOF series of low cost open frame ac-dc power supplies. The VOF series has a low no-load power consumption of <0.5 W and efficiencies up to 83%. The combination of efficiency and competitive pricing makes this series ideally suited for use in ITE, industrial, and consumer electronics applications.

The VOF-10 and VOF-15 provide continuous output power, universal input (85-264 Vac), and are offered in 3.3, 5, 12, 15, 24, and 48 Vdc output voltages. The VOF-10 measures 2.6” x 1.8” x 0.9” and the VOF-15 measures 2.8” x 1.9” x 0.9”. Protections for over voltage and over current conditions are included.

CUI Inc
www.cui.com

Linear Actuators

Linear Actuators are a class of mechatronic systems with some unique design constraints.  As a result there are dozens of approaches, dozens of vendors, the option of designing the actuator from scratch, and, frankly, a lot of confusion.  The problem lies in the fact that the actuator as a subassembly is the combination of a number of separate technologies.  This means there are a number of design tradeoffs incorporated into the resulting actuator that must be acceptable in order to use that actuator.

Categorizing linear actuators is not entirely straightforward because many categories overlap.  The “motive power” category can be any type of power source, rotary motor or linear motor powered.  Linear motor solutions are much more commonplace in linear actuators today due to declining costs for this technology choice.  But in a linear motor based actuator, the linear motor is both the motive power and the mechanical transmission at the same time.

Categorizing linear actuators by their mechanical transmission style is another approach.  The most common categories are screw type, belt and linear motor.   But the motive power for a screw based actuator could be a stepping motor or a servo motor.  The stepping motor is predominant because of it’s suitability for positioning, but it may be underpowered for some applications where a servo is needed.   So the linear actuator transmission category can have overlaps because of the different motor types that are used in conjuncion with it.

Price seems to be one means of eliminating the ambiguity.  Stepping motor and lead screw combinations are popular because they are economical and maintaining 0.001″ accuracy is very easy.   Linear motor systems are capable of .5 micron accuracy with little or no friction, acceleration and speed that is incredible, but generally the higher performance comes at a higher price.

But in the end, the selection process is best guided by the criteria of the application.  The list is, thankfully, short.  Load weight or force that must be generated, speed, accuracy and life expectancy or number of cycles of operation.  This last is probably the key determinant in system selection.  Long life or high cycling goals lead to linear motors actuators with little or no friction. You have to familiarize yourself with the overall field because the tendency of confusing the technology and the application needs.

At the recent Semicon gathering of manufacturers involved in semiconductor manufacturing, a lot of attention is given to the mechatronic content of machinery.  And as far as I have been able to determine from many different market research projects, semiconductor manufacturing is one of, if not, the largest market for mechatronics every.   So it’s also not a surprise that a lot of vendors come to the Semicon show with their latest and greatest product offerings.

Among the most interesting, Nanomotion continues to extend the reach of piezoelectric linear motors, yet another technology choice within the linear actuator sphere.  Piezo motors have only one moving part, and meet the high precision, high reliability criteria.  With increasing usage, there has been decreasing cost for this unique solution, along with superior position feedback technology and excellent packaging for space constrained applications.

In addition, IKO has released a number of new linear actuator assemblies, both screw driven and linear motor driven.  They are also showing a number of unique 2-axis configurations one of which is the thickness of a tape reel and is targeted to unloading parts for electronic pick and place machinery.

Brilliant examples of manufacturers continuing to integrate mechatronic technology to make it more convenient for the customer.

The Next Industrial Revolution

The industrial revolution was a period of unprecedented expansion of technology that lead to a huge increase in economic opportunity.  It was a period marked with great inventiveness that transformed the Europe and America.  The power of that inventiveness echoes through today.

Similarly, in recent years, there have been a number of significant breakthroughs that offer great potential for the improvement of many current technologies.  But more subtle transformations are taking place throughout the industrial landscape that offer new opportunities yet to be explored.

In many areas of part production, there are solutions that offer reduced cost per part.  The emergence of new CNC’s that are available at the $10,000 level reduces the amortized cost for producing parts by as much as 500%.  Simply put, it you have to produce 1000 parts on a machine tool, the final cost of the part is significantly impacted by the cost of the machine tool.  A $50,000 machine tool will cost $50 per part across 1000 parts.  A $10,000 machine tool will only cost $10 per part.

This economic shift may make it possible to enter a market with an improved price point for an existing product, or create an opportunity to do something new that wasn’t possible because of cost and volume constraints.

In similar fashion the metals industry has consistently worked to developed processes and technology that allow part cost reductions, and more recently, smaller batch sizes for certain applications.  The smaller batch size has the same effect on cost, it lowers the investment cost for improving old designs or coming up with new ones.

The same trend is in place in the controls arena.  Processor technology that used to cost $20. a few years ago is available now for $2-3 and network versions that permit Internet interface are available for around $5.  This makes it practical to embed intelligence and communications in products even if the application is relatively simple.  The low cost is a compelling value in many products.  And in many arenas there are libraries of application code that already exists that may provide 60% or more of the development code for something you are working on.

Energy is still a bit of a limitation.  We don’t have a “Mr. Fusion” nuclear reactor that runs of kitchen scraps.  But things are looking up in this area with lithium based batteries making great strides in energy density.  And there is substantial improvement on the way.

But the real point here is;  Dust if off and Try it Again.  Take those “back of the napkin” sketches you’ve been tinkering with or thinking about and look at them again from the perspective that there dozens of technology improvements out there that will reduce the cost of the product you were thinking about a couple of years ago.  The change in the economics, as amortized cost, or the cost threshold to get your first batch of parts made, are factors that have a huge impact on the feasibility.

It just may be the time for a breakthrough.  A second industrial revolution.

Torque, Control and Adaptive Gain

Torque is a very important aspect of motion control.  Torque in a car (electric or combustion powered) is what turns the tires.  Torque control is the ability to control the amount of torque needed based on conditions of the application.

In the car, starting torque requirements can be very high, depending on how fast you want to accelerate.  Running torque, the amount of torque needed to overcome air drag, is very small.   If you want to reach 60 miles an hour in 4 seconds or less, like a Corvette, you will probably need around 450 horsepower.   Cruising on the freeway at 65 miles an hour, constant speed, will probably only require 5 horsepower.

So the power requirements for what appears to be “the same” application can vary wildly, 100 times the power, depending on the circumstances.  That’s where control and regulation come in.   The question being, how fast is the rate of power being dissipated over a small instant in time.  This is the domain of calculus, the first derivative of power over time.  This will determine how fast the control system monitors and updates the value of the power being controlled.  This can also be referred to is as the dynamic rate of the control system, the change in time for the power rate to be measured.

In AC drives, the dynamic response of the drive is a crucial parameter in order to specify the right drive for the application.  Large systems like paper rolls, which can weigh hundreds of pound, have a very slow dynamic rate and a drive for this application should have a dynamic response that is comparable.

Hard disk spindle drives, which have tiny loads and must regulate speed and acceleration based on 2 millisecond seek times, must have extremely fast dynamic response.  The high rate of acceleration requires that torque is regulated in the microsecond range.  Regulating a paper drive with a control designed for hard disks would not only be a waste, but the high response rate in the control would probably lead to instability in the control.

But more complex conditions exist in the real world that must be considered.  What happens when the load is changing?  When you have to palletize beer bottles, every ten cases of beer completes a layer on the pallet.  There are 8 layers to the pallet.  So you start with an empty pallet and end up after 8 identical moves with 3800 pounds of beer.  How do you set the gain?

Either you use an average value equivalent to half the payload weight and live with the results, or you need something that reloads the gain value as the load changes.  Both techniques can be done, both work, but the ideal solution is the second, adaptive gain.  Something that is adaptive, however will require some pretty advanced programming to consider all possible conditions.

And that is the new frontier in robotics.  If robots are to work in human service, they have to be able to operate in a reduced torque mode so that they cannot produce forces that exceed human strength and frailties.  But there are other conditions where the robot’s superior strength can be extremely helpful.  So the current generation of drives will have to incorporate increasingly complex adaptive gain controls in order to make human service robots safe and practical.

Adaptive gain is a discipline that has been talked about for at least a decade in the control community, but it’s been somewhat of a technology looking for an application.  There are the occasional situations where adaptive gain would really be “cool”, but not any widespread applications.  Well, the next great application for adaptive gain will likely be human service robots.  Coming soon to a neighborhood near you.

Six degrees of freedom and high precision

Parallel kinematics (PKM) precision positioning systems have many advantages over serial kinematics stages, such as lower inertia, improved dynamics, smaller package size and higher stiffness. Hexapods, a type of parallel kinematics positioning system, can move masses of 50, 200 or even 1000 kg with micron accuracy such as that required in medical applications. This particular Hexapod system, the M-810, is built with six, high-resolution electro-mechanical or piezoelectric actuators acting on a common platform. It is the familiar flight simulator design, but considerably more precise: in place of hydraulic cylinders, the Hexapods are driven by accurate, precision-controlled rotary or linear motors.

Different drive principles are used, depending on the application: Hexapods with NEXLINE® drives make a positioning system that is vacuum compatible and non-magnetic.

These Hexapod systems include a controller that lets you set a pivot point anywhere inside or outside the Hexapod working space. The freely definable pivot point stays with the platform, no matter how it moves. Moves are specified in Cartesian coordinates and the PC-based controller transforms them into the required motion-vectors for the individual actuator drives.

The miniature hexapod system delivers more than 10 lb of force and motion in all six degrees of freedom.  This 6-axis robot can be used for manufacturing and part placement that requires high precision for microscopy applications or laser and optical alignment. Its size is 10 cm in diameter and 11.8 cm in height. Minimum incremental motion is 0.2 microns (40 nm resolution). Travel ranges to 40 mm linear and 60° (rotation). Velocity is 10 mm/s.

PI (Physik Instrumente)

www.pi-usa.us

Motor and Drive Combinations

There is a subtle premise that often escapes us as we talk about motors and the controls that run them.  It is that the motor and controller operate as a package.  In most situations, a customer specification is for input voltage and output torque and speed.  That’s all that is important.  How you get there doesn’t matter a great deal.

But ironically, most motor manufacturers are predominately mechanical engineering centered.  And most drive electronics companies are electronics centered.  And they have very little in common with each other.  Except that their products must work together.  And oftentimes, that’s where the trouble starts.

The drive manufacturer warrants that his drive will produce current and voltage.  But the the motor can have very complex constraints to deal with in response to the excitation of the electronics.  How accurately a 6 step approximation of the sine wave performs, for example, can result in overheating in the motor depending on the loading of the system.  And as the motor winding heats up, the resistance in the motor can change dramatically, especially in the low inductance windings that are common in many specialty motors available today.

Then there are the cabling issues for connecting the motor and drive electronics.  The ac drive industry found out quickly that long wire runs can result in stored energy in the wires themselves.  Standing wave phenomena could cause higher voltages than expected and blow holes in the winding insulation in the motor.

Power semiconductor prices have fallen considerably in the last few years creating situations where it is sometimes cheaper and more reliable to put in parallel devices than to attached single power devices to large heat sinks.  This leads to some serious new options for packaging the electronics.  How about drive circuits in the end bell or junction box attached to the motor?  Actually, some models of the GE ECM motor (now owned by Beloit) are ac fan motors with variable frequency drives and intelligent controls built directly into the motor end bell.  You may have one in your main air handler in the air conditioning system of your home.  I was surprised to find out that I did.

I used to think that thermodynamics of these systems would be impossible to manage.  But the fact is that the drive efficiencies are getting really good.  One team I worked with was producing a 500 Watt brush drive that only shed about 20 Watts of loss at full load.  That’s some incredible efficiency.  So the notion of integrating motors and drive electronics is much more reasonable than it used to be.  And there are stepping motor packages that have been doing it for years.

So where is this all heading?

The fact is that the motor and drive electronics must work together as a package.  There is an increasing need, and an opportunity to create further performance enhancements, by the two technologies working more closely together.  More innovation will lead to better energy efficiency and new design opportunities and a chance to recharge (pun intended) an industry that has been losing share to offshore competition in the last few years.

Scientists Create First-Ever Circuit Powered By Light

For the first time, scientists have created a circuit that can power itself, as long as it’s left in a beam of sunshine. Created by scientists from the University of Pennsylvania, the world’s first photovoltaic circuit could eventually power a new line of consumer devices or even model the human brain.

Right now the creators can only coax minuscule amounts of electricity from their photovoltaic circuits, far too little to power consumer electrical devices, although those amounts could quickly skyrocket.  There are plenty of other ways they say that they can squeeze more electricity from light. Right now only about 10 percent of the photovoltaic circuits on a glass side work. Increasing that number will boost the power output.  Another way to get more power is by turning their 2D structures into 3D structures. Stacking multiple layers of light-collecting and electricity-using circuits would also boost power.

The photovoltaic circuit is a scientific breakthrough, not a technological one. These new circuits will most likely never replace their silicon counterparts.

Photovoltaic circuits could be ideal for other applications, however, such as powering tiny robotic devices or running computer calculations at the speed of light.  Far into the future, these circuits could even be used to set up as artificial neural networks that could model the brain.

At their most basic, computers represent data as on or off, a “0″ or a “1.” Using light instead of electrons, these photovoltaic circuits could store data from, say, one, two, three or four. Each number would correspond to a certain wavelength or color of light — red, green, blue and yellow, for example. To model the human nervous system, each color of light could correspond to a different neurotransmitter, say red for dopamine and blue for serotonin.

The potential applications of the technology are huge, but will take years to develop into any kind of practical equipment.

www.news.discovery.com

DASH, The Robotic Cockroach, To Save Lives In Haiti

UC Berkeley’s Department of Electrical Engineering is developing mini-robots to help locate earthquake survivors easily, cheaply, and quickly, and without jeopardizing the lives of rescuers.

Magnetics 2010 and Motion, Drive & Automation

There is a small industry conference that takes place every year with a lineup of industry experts that is top notch by any standard.  It’s called the Motion, Drive and Automation Conference put on by E-Drive magazine.  This year it is located at the Disney Hilton Resort in Orlando and is taking place on January 28 & 29.   The conference includes a wide range of industry experts from many fields of advanced electric motor design, advanced motor control concepts, power semiconductors and state of the art motor testing system.  There will be a lot of technical and product presentations that showcase leading edge technology in electric motors, precision gear reducers, new technology for motion sensing, and a number of improved power semiconductor devices for the motor control industry.  This is a great place to get up to date on the latest technology that will impact of motor and control technology across many industries over the next few years.

In addition, the Magnetics 2010 Conference will be running concurrently at the same venue.  Magnets are a strategic material without which many motors would simply not operate.  In the ever-changing motor industry, there is always a new design that seeks to make an enhancement over previous solutions, or introduce a new solution to old problems.  Declining prices for Neodymium Iron Boron magnets over the last few years have created a number of novel design shifts which have been instrumental in bringing more varieties of permanent magnet machines into the forefront of motion control and mechatronic technology.  To the point where over the last two years a resurgance of permanent magnet rotor designs have been created to improve the energy denisty and lower the cost of specialty motors in washing machines and air conditioning compressors.

This last development, combined with the forecast increase of hybrid electric car sales coming this year, are expected to increase the sale of permanent magnets by 10-15 percent by 2011.  That’s a staggering jump in a market that is almost exclusively supplied by China.  And there is no assurance that China can meet the forecast production.

The US Department of Commerce usually has a say in the sale of products or businesses to foreign countries that are deemed to be strategic or sensitive technology.  In fact, I got stuck in a situation where my employer was told specifically that we could not sell a CNC controller to a Korean customer.  That’s pretty small potatoes compared to controlling the supply of permanent magnets which influences billions of dollars worth of electric motors manufactured and sold all over the world.  So it strikes me as a little odd that the sale of Magnequench to its current owners, Neo Materials, was completed without a much discussion. leaving the US without a domestic magnet supplier.

There will surely be a lot of discussion about this situation at the conference, and I will be in attendance to get the latest information on the subject.  So look forward to a review of the conference in an upcoming post.

Multi-Touch ‘Resistive’ Touchscreen Controller Chip

As the latest high-tech devices such as smartphones, mobile internet devices and netbooks adopt multi-touch touchscreens to support increasingly sophisticated ‘apps’ and games,STMicroelectronics has introduced a multi-touch ‘resistive’ touchscreen controller chip to optimize the Bill of Materials of the electronics supporting this advanced capability. The STM32TS60 is the first member of ST’s new STMTouch family, which offers a broad portfolio of solutions including multi-touch devices and proximity and touch-key sensors.

The new multi-touch controller detects up to ten simultaneous touches with fingers, nails or stylus, enabling application designers to replace complex menu sequences with more direct and natural user controls. Actions made easier with multi-touch capabilities include browsing and selecting options, handwriting and data entry, arranging and sizing windows, picking up and dragging images, and fast and intuitive game play. Other abilities include drawing pictures, using touch pressure to adjust line thickness.

Employing resistive touch-panel technology, the STM32TS60 controller offers customers a real alternative and complements the recent industry trend for using capacitive touch technology. Resistive technology is a cost effective and mature high-volume solution that has seen dramatically improved performance over the past few years in terms of durability and display transparency. In addition, it easily overcomes EMI (electromagnetic interference) noise issues, which can be an inherent limitation with alternative touch technologies. Resistive technology is already widely used in PDAs and similar touch-enabled devices and the screens are readily available in standard LCD sizes and at competitive prices.

The new chip combines the company’s STM32 microcontroller architecture with PMatrix^TM Multi-Touch technology from ST‘s partner Stantum to achieve fast response times while minimizing system complexity and component count.

The STM32TS60 single-core microcontroller is an added-value solution compared to other expensive multi-core processor or digital signal processors (DSPs) requiring specialized programming expertise.

The STM32TS60’s high EMI immunity makes it suitable for use in multi-function wireless products such as cellphones, notebook PCs, netbooks and mobile Internet devices. Moreover, its low power consumption helps to maximize operating times and recharge intervals, and is a direct benefit of the STM32’s energy-saving design features and ARM® Cortex™-M3 processor conceived for power-sensitive embedded applications. In addition, very-low-power idle mode with ‘wake-up on touch only’ helps further extend mobile battery life.

The STM32TS60 is housed in a 7 x 7mm 144-pin UFBGA package, and is now sampling to lead customers. Volume production is expected for Q2 2010.

www.st.com

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