Tips to Understanding Your Touch Screen

original touch screenIf Justin Bieber songs are all over your playlist, chances are you don’t even remember a time before touch screens; they are just a part of your every-day life, ubiquitous and expected.  To the rest of us, touch screens are still a bit awe inspiring.  ATM machines, cell phones, car navigation systems, retail point-of-sale terminals, monitors and industrial control panels – they are almost everywhere.

Credit the Brits for bringing us touch screen technology.   Historians consider the first touch screen to be a capacitive touch screen invented by E.A. Johnson at the Royal Radar Establishment in Malvern, UK between 1965 – 1967 which he was developing for air traffic control.  However, it wasn’t until 1973 that Bent Stumpe and Frank Beck, engineers with CERN, developed a transparent touch screen that was put to actual use by CERN.

American inventor and University of Kentucky instructor G. Samuel Hurst, PhD developed the transparent resistive touch screen in 1977, still in use today.  Advancements in touch screen technology came in 1977 when Siemens developed the curved touch screen; in 1983 when Hewlett Packard developed the troublesome infrared HP-150 home computer with a touch screen; in 1993 when Apple introduced the Newton PDA and IBM the Simon PDA followed in 1996 by the Palm Pilot PDA (remember those?).

The 2000s brought an explosion of touch screen devices into all facets of manufacturing and daily living, especially Apple’s iconic iPhone in 2007.  Although touch screens are still in their relative infancy, already it is hard to imagine life without them.

We know it’s not magic, so how does touch screen technology actually work?  Keeping it very basic, these are the three major components to touch screen technology:

  • Touch Sensor – a panel with a touch responsive surface based on one of three different types of sensors including resistive (common), surface acoustic wave, and capacitive (used by most smart phones).  The sensors have an electrical current running through them and touching the screen causing a voltage change which signals the touch location.
  • Controller – the hardware that converts the voltage changes on the sensor into signals the device can receive.
  • Software – tells the device what is happening on the sensor and the information coming from the controller and allows the device to react accordingly.

So what’s the difference between resistive and capacitive and which one do you have?

  • Resistive – uses six basic components including a screen base, glass panel, a resistive coating, a separator dot, a conductive cover sheet and a tough top coating.  When a finger or stylus presses down on the top surface, the two metallic layers touch, the surface acts as a pair of voltage dividers with connected outputs. This causes a change in the electrical current. The pressure from your finger causes conductive and resistive layers of circuitry to touch each other, changing the circuits’ resistance, which registers as a touch screen event that is sent to the computer controller for processing.
  • Capacitive – uses a layer of capacitive material (capacitive means it senses anything conductive or that has a dielectric different from that of air and yes, humans are conductive) to hold an electrical charge; touching the screen changes the amount of charge at a specific point of contact.  Capacitive sensors can be constructed of copper, indium tin oxide (most touch phone screens use this type), and printed ink.

Touch screens, even the industrial sort, are easily damaged.  Common touchscreen problems include:

  • Calibration – Touch screens can lose their calibration and may not judge the user’s input correctly, causing incorrect operations requiring the screen to be recalibrated.
  • Dirt and Grease –  Frequent touches cause grease to soon be visible on the screens. If left uncleaned, the grease and dirt damage internal components. Use the cleaning cloth that came with the screen to avoid touch screen repairs.
  • Operation and System – The relatively delicate nature of touch screens and sheer age are often the cause of errors and calibration problems.
  • Hardware – If you’ve ever dropped your smart phone or a POS terminal, you know it doesn’t take much to cause catastrophic damage.  This type of damage can sometimes be repaired but is often “fatal” to the device.Get Fast & Accurate Quotes for Idustrial Touch Screen & Monitor Repair

If you have damaged commercial or industrial touch screens that are no longer under warranty, they can often be repaired.  Seek out an industrial electronic repairs firm that has good experience repairing touch screens, that offers free evaluations and that warranties their work.

A Case Study for Creative Solutions for Allen Bradley Touch Screen Repair

Allen Bradley Touch Screen Repairs

Successful Allen Bradley Touch Screen Repair

Case Study for Repairs on aging Touch Screen:   Who says electronic repair work doesn’t require creativity?  Yes, experience, education, skill, and patience (lots of that!) are necessary.  But a good dose of creativity is just what can make the difference in solving a challenging repair.

This aging and long out-of-warranty Allen Bradley touch screen control panel was deposited on our loading dock nearly dead on arrival.  I say “nearly” DOA because while it did power up, which was a definite plus, it was otherwise non-responsive.  Among other age-related problems, a video problem on the motherboard was causing no video to the LCD (digital) output or on the VGA output (analog).

The customer was anxious to get this unit repaired and back in service and I mean this exact unit, not a replacement.  Our expert tech staff determined that even though major replacement parts for this unit were unavailable (such as the very-important LCD panel) it could still be repaired with some ingenuity, some clever secondary market purchases, and access to our deep parts “boneyard”.  And, despite some rather  “invasive surgery”, it would still look and perform identically to the original.

With approval from our customer, this unit was repaired almost entirely with used parts.   Even the case was expertly modified to accept a different panel.   We retrofitted the backlight, and analog to digital interface board from the replacement monitor to fit inside the cabinet but had to discard the monitor power supply, and route power from the existing source.  When “surgery” was complete, the touch screen was accurate and calibrated at the very first test and required NO adjustments!  Way to go!

My motto has always been, and I mean always, where there’s a will, there’s a way.  This customer really needed their Allen Bradley touch screen control panel to be back up and running and with no replacement units immediately available, by gum we were STILL going to find a solution!

Hats off to our extraordinary tech staff for finding and executing a workable and cost-effective solution and to our customer for bravely approving an “alternative” approach.

What You Should Know About Used or Shelved Industrial Electronic Equipment and How to Evaluate

Get Free & Accurate Quotes for Expert Industrial Electronic RepairsBuying used industrial electronic equipment or reusing shelved or mothballed equipment can indeed save a lot of money, BUT it can also result in some costly problems.

When you buy used you can end up buying someone else’s problems and if you dig out your own mothballed machinery, you can only hope that it was put away and marked properly.

No matter what size plant you operate, you can employ Predictive Maintenance technologies to evaluate the operating condition of used or mothballed equipment. You probably already do this on some level, only you didn’t call it anything fancy. You still don’t have to call it anything fancy, but applying some fundamental tests and organization to the process can help make it more effective thus saving time and money, and isn’t that what we all want to do?

The only way to 100% determine the operating condition of used equipment is to test it under load, under normal operating conditions. However, this is often just not possible. Other useful evaluation tests you can perform include:

  1. Start with simple low/no cost tests such as rotating a shaft to see if the bearings and components are damaged, bent or corroded. Purge grease fittings to check the lubricant. These simple tests can quickly show serious potential problems.
  2. Temporarily install the unit in a test fixture such as a dynamometer with accurate diagnostics such as real time vibration analysis; a bit more costly but very useful.
  3. Vibration analysis can quickly detect unbalance, misalignment, bent shafts, resonance, bearing failures, gear mesh problems, motor problems and much more. Well worth the effort.
  4. Infrared thermography tests the temperatures in the unit to detect areas that are hotter or colder than they should be such as what you might find in switch gear, gearboxes, circuit breaker panels, and motor
  5. Tribology and oil analysis compares chemicals and physicals of the oil against clean virgin oil to see if the oil is still adequate
  6. Ultrasound analysis tests for quite a number of things including detecting electrical arching and corona discharge.

These are a sample of Predictive Maintenance technologies from the basic to the complex, and there are yet still more options. Schedule when you will test your equipment and document the results for each piece, including the cost avoidance figures which management will want to see – you will be glad you invested the time and effort when you realize long-term savings and prevention of disastrous failures.

If you are considering mothballing your industrial equipment but aren’t entirely sure how, take a look at this article I saw on Industrial Equipment News.com as well as others you can find on that site.

Consult an expert in industrial electronic repair if you want to have your equipment evaluated by a professional or you need such services as plc repairs, touch screen monitor repairs, servo motor repairs or other repairs. Using the services of a professional industrial electronic repair shop provides you with a warranty even on an older, used piece of equipment which can be invaluable.