Category Archives: Guides

How do fiber optic cables carry light?

Nowadays, nearly everyone is talking about fiber-optic cables. These cables are now commonly used in telephone systems, cable TV systems and the Internet. One of the main advantages with optics cables is their huge bandwidth. That means fiber optics cables can carry far more signals than copper wires can. Usually made of optically pure glass, these cables are very thin – nearly as thin as human hair. Because of their high signal carrying capacity, optical fiber cables are also used for mechanical engineering inspection and in medical imaging. Optical fiber cables are made of long, thin strands of extremely pure glass. With a diameter close to that of human hair, several strands are bundled together, to form cables that are used to transmit light signals over long distances. When examined closely, each single fiber can be seen to consist of three parts.

The central core of the fiber is made of glass and this is where the light travels. The core is covered with a cladding, which effectively reflects light back into the core. The core is surrounded by a buffer coating, mainly for protecting the fiber from moisture ingress and physical damage. Optical cables contain hundreds or even thousands of such optical fibers arranged in bundles. On the outside, a jacket, also called the cable’s outer covering, protects the cable.
In general, there are two major types of optical fibers – single-mode and multi-mode. With a small core of about 9 microns in diameter, single-mode fibers can transmit infrared laser light having wavelengths of 1,300 to 1550 nanometers. On the other hand, multi-mode fibers have core diameters of about 62.5 microns, capable of transmitting infrared light of wavelengths from 850 to 1300 nanometers.

Other types of optical fibers can be made of plastic as well. These usually have a larger core of about 1 mm diameter, capable of transmitting visible red light of wavelength 650 nm, such as from LEDs.

Light always travels in straight lines. This is easily seen when a flashlight beam is shown down a straight long hallway. You can see the entire length of the hallway until the next bend, but beyond which nothing is visible. However, placing a mirror at the corner will allow you to see round the bend. This is possible because light from around the bend strikes the mirror and reflects down the hallway. If the hallway were to be very winding with multiple bends, lining the walls with mirrors will help. Light bounces from side-to-side and travels down the hallway making the entire path visible. This is exactly how an optical fiber works.

Light travels through the core of the fiber-optic cable, constantly bouncing off the cladding. This follows a well-known principle of optics known as total internal reflection. Very little light is lost in total internal reflection from the cladding, allowing light to travel long distances within the cable.

Although the core is made from optically pure glass, some impurities remain. These degrade the light signal as it travels down the core. The extent of signal degradation depends both on the impurities present in the glass used for the core and the wavelength of the light traveling through it.

Integrated Motors Simplify Motion Control

With machines getting more robust, smaller, less expensive and more reliable, engineers are facing the challenges of designing newer types of motion control. One way of addressing such motion control challenges, without being an expert in mechatronics is to use integrated motion control systems. Typically, these solutions combine the motor, the drive and the system components within a single unit. The system components include the intelligence or motion controller and input outputs all onboard. The use of an integrated solution allows the designer to focus more on the development of the machine and less on solving compatibility issues between various system components. The integrated motion system usually has all the components within a complete unit and sized for proper use. The decision to use an integrated motion system or an integrated motor usually depends on several factors. Major among them are requirements based on machine size, cost, reliability, modularity and distributed control.

With integrated motors, engineers can reduce the amount of space a machine needs. This is mainly the result of consolidation of components resulting in elimination of cabling. For example, an integrated motor may replace a drive and motor housed in separate enclosures, eliminating one of the enclosures. The panel space required reduces significantly for an integrated motor, while for a multi-axis system the real estate reduction can be substantial. However, an existing machine design must contain adequate space to house the integrated motor as this type of motor is larger than conventional motors.

Using integrated motors results in definite cost savings in contrast to using conventional components. One of the major saving in expenses comes from the absence of cabling that is no longer required with integrated motors. For example, the conventional drive may be located in a centralized cabinet with the motor a distance away on a long conveying machine. This arrangement needs considerable power cabling and feedback wiring between the motor and the drive. With the integrated motor, the drive being directly on the motor, much of the cabling is eliminated contributing to cost reduction.

With improvements in motor technology, the concern with reliability in integrated motors is outdated. The major point of concern earlier was heat buildup and dissipation. With reduced components making up the system, the reliability of integrated motors has improved because of the lower number of wire connections used. Better construction technology has improved the efficiency, decreasing the heat generated and the need for dissipation.

Industrial automation today requires modular machines. That essentially means smaller machines focusing on singular tasks combined to form a bigger system responsible for multiple functions. The smaller machines may operate independent of each other. This arrangement is beneficial because it allows engineers to change on modular section and transform the system into another customized machine. The modular concept is beneficial in shipping individual modules to the factory floor as the motor and drive of the integrated motor is placed directly in the machine.

As more and more industrial control is through PLC or Programmable Logic Controls, motor operations and synchronization through digital data signals is the norm. Since each integrated motor has its own controller, a distributed control system provides faster response and greater accuracies.

Connector Use Lowers Wiring Costs

Contrary to popular belief, hardwiring does not always minimize wire installation expenses. Hardwiring is a popular concept for those who regularly design and build industrial machines. People perceive it as one of the most common ways of saving installation costs when bringing power and signal to the machine. However, when the full range of wiring costs are factored in, these cost savings really seem just as a mirage does.

Installation costs typically involve time and materials, including the cost of the wire, cables, accessories and labor. However, if you look closely, there are less obvious hidden installation costs as well. These have individual considerations for labor and time-to-market.

For example, consider machines that need to be disassembled for shipping and then reassembled before startup. That means parts in the machine will have to be hardwired twice – once while testing and then again after shipping. Additionally, errors while wiring in the field are quite common, mostly when local electricians unfamiliar with the machine are handling the wiring. If you are lucky, such errors may only cause a delay in commissioning the machine. However, there can be worst-case scenarios, and faulty wiring may even damage the machine leading to expensive repairs. Along with such cost of errors, hardwired systems can be complex and expensive to test, so the cost of testing goes up as well.

As a rule of thumb, you can expect the hidden costs to go up exponentially with the number of connection points the machine has. Fortunately, use of connectors can help avoid all these hidden costs. Of course, connector components do add an upfront investment, but this money will be recouped and then some as connectors enable lower-cost machines, the machines can ship faster, they can be commissioned more quickly and offer ongoing savings.

Using connectors, engineers can build modular machines faster and with lower expenses. This approach to machine design allows engineers to pre-build common subsystems and components, and test and stock them for installation. Reusable modules lead to many machines being designed with common control panels, junction boxes, motor assemblies and populated cable tracks.

Connectors are a real advantage for shipping new and large machines, especially if these machines have to undergo some level of disassembly also. Disassembly usually involves unplugging cables from the bulkhead connectors of the panel, while connections and routing internal to the panel remain undisturbed. The process holds true for sensors and data cables, motor assemblies and junction boxes also.

At the destination, the machine requires all disconnected wires to be reconnected once again. A local electrician helped with a set of wiring schematics can simply perform this. Even if the electrician knows very little about the machine and the way it works, there is little chance of them making costly mistakes and adding to startup delays. Most modern connector systems are designed to disallow simple wiring errors. Where large, complex machines are to be installed and commissioned, connectors can reduce the time to a matter of days in place of the several weeks that hardwiring would have taken.

How to Avoid Cable Damage from Oil

Electrical cables are routinely exposed to several kinds of damaging chemicals in the environments they pass through. However, the most damaging of them all is chemical exposure to oil. Many industries and infrastructure settings use oil as a lubricant or as coolants. Such oils react with the polymers used in the cable insulation and jacketing to inflict molecular damage.

If this is ignored, oil can severely damage cables. This ultimately results in failure of the cable, system downtime and replacement expenses. With advanced production facilities such as in automotive assembly, requirements of better performance characteristics in renewable energy and regulatory changes, more people are now aware of oil damage to cables.

Fortunately, better cable manufacturing technology is now allowing cables to resist the effects of lubricating and cooling oils. However, it is necessary to know how oil degrades cables, how oil exposure problems can be diagnosed and how cables can be selected so that they resist oils over the long haul.

Insulation and jackets of cables are typically made of polymer compounds. Although they may have the same family name, not all these polymers show the same physical properties, including oil resistance. For example, some PVC compounds may show better oil resistance, while others have a higher degree of flame resistance. Manufacturers change the PVC formulation according to the properties and applications desired.

For example, addition of certain flame-retardants, stabilizers and filters allow PVC to exhibit enhanced characteristics of this type. However, improving or enhancing one characteristic usually comes at the cost of other performance traits being affected or being completely lost.

That explains why not all wire and cable insulations show equal performance with oil resistance in particular. The chemical, mechanical, environmental and electrical attributes vary depending on the individual compound formulations. To help promote resistance to fatigue and increased flexibility, most insulating compounds have a specific amount of plasticizers added to their individual formulations. When such compounds are exposed to processing oils for coolant or lubrication, the plasticizer diffuses from the compound or the material absorbs the oil.

With the plasticizer diffusing out of the compound, the oil causes insulation hardening, resulting in loss of flexibility and elongation properties. If oil is absorbed, the insulation swells and softens resulting in degradation of tensile properties.

In short, oil causes the insulating compound to lose its primary role virtually as an effective insulator. This creates a hazardous situation not only to the functioning of the industrial machinery to which it is connected, but possibly also to human life. Ultimately, this can result in expensive downtimes, expensive repairs and in the worst cases, replacement of the entire machinery.

Testing can help determine how a cable will react in environments containing industrial oil. UL has standardized these tests and they are commonly known as Oil Res I and Oil Res II tests. In these tests, cable samples are continuously immersed in IRM 902 Oil at elevated temperatures for specified periods. The mechanical properties of the cable samples are observed for physical damage caused by the exposure to oil. The latest UL standard for these tests is AWM Style 21098.

How Opto-Couplers Help with Intrinsic Safety

Electrical equipment and wiring are used in different environments, including hazardous locations, where there is always a risk of explosion due to any malfunction in the wiring or equipment. To mitigate this risk, electrical and thermal energy generated must be limited to a level below that required to ignite a specific mixture of the hazardous atmosphere. This technique of designing electrical equipment and wiring to be safe under normal or abnormal conditions is called intrinsic safety. Therefore, intrinsically safe wiring and equipment are incapable of releasing adequate thermal or electrical energy under any operating condition to cause a combustible or flammable atmospheric mixture to ignite.

Independent third party agencies such as the UL or Underwriters Laboratories, CSA or Canadian Standards Association, FM or Factory Mutual Research Corporation and the MSHA or Mine Safety and Health Administration, test and certify equipment for intrinsic safety. For use in explosive atmosphere, the agencies test and verify equipment for compliance to IEC international standards. Within the IEC 60079 series, the standard IEC60079-11 specifies the construction and testing of intrinsically safe apparatus intended for use in an explosive environment.

According to IEC60079-11, the basic principle in achieving intrinsic safety is for limiting the energy in the power circuit, preventing unusually high electric arcs, ignition sparks or high temperatures that could create ignition energy required to cause an explosion. For limiting the power or energy, designers should implement a resistor or fuse in series for limiting the current and a Zener diode in parallel for limiting the voltage.

Additionally, IEC60079-11 also requires that conductive parts of intrinsically safe circuits be separated from the conductive parts of non-intrinsically safe circuits. The separating distances have different requirements through insulation structures, and this includes clearance, separation and creepage distances. For example, casting compounds specified includes epoxy resins, while solid insulation specified include silicone and polyester film.

Apart from providing galvanic isolation, opto-couplers have internal clearances, which include DTI or distance through insulation. This is a part of the insulation and safety related specification of opto-couplers. DTI provides galvanic isolation through optical technology, forming a straight-line thickness distance between the LED emitter and the detector within the opto-coupler. The DTI of the opto-coupler meets the separation distance requirements 0 to 2 of the gas zone classification. This depends on the voltage level of protection required.

Typically, isolators with structural DTI less than 20µm cannot achieve the stringent separation distance requirements of intrinsic safety criteria. Special opto-couplers, such as the ACNV series from Avago, have a 13mm creepage/clearance, with insulation material classified as casting compound. This allows the ACNV opto-couplers to achieve up to the 375V level of protection. Similarly, ACNW/HCNW opto-couplers from Avago, with 10mm and 8mm creepage/clearance, can meet up to 60V level of protection.

Such intrinsically safe opto-couplers are routinely used in applications for measurement of level, pressure and temperature in flow meters and transmitters. Meeting safety requirements, these opto-couplers provide the reinforced insulation required between field sensors and micro-controllers on control boards. Typical examples of such applications are in the explosive atmospheres of petrol stations and sewage, where fluid pumps and flow meters are used.

Raspberry Pi Alternatives

f you have been using single board computers such as the RBPi or Raspberry Pi and Arduino, you would have certainly found them great as do-it-yourself boards for hacking and for setting up your own design. However, using these boards can bring up a natural curiosity to look at other alternate hacker boards similar in size and functionality to the RBPi.

Listed here are some boards comparable in prices to that of the RBPi, and with community support. They are good for transitioning to low-cost commercial volume manufacturing, while being compatible and easy-to-use.

According to the director of ecosystem and marketing program of Freescale, Steve Nelson, one should look for five important features while selecting an SBC: Simplicity in installation and during operation; Staying power or popularity with users; Stability against regular rebooting or updating; Security of design; and Standards of compatibility irrespective of the manufacturer.

Udoo: Although more expensive compared to RBPi, Udoo offers a unique experience of Linux and Arduino SBC. It runs on an ARM i .MX6 processor from Freescale, has 1GB DDR3 RAM and offers 76 fully available GPIO. Apart from this, it has a Wi-Fi module, one Ethernet RJ45, 3D GPUs for graphics, HDMI and LVDS. Other features include a pair of mini USB and mini OTG, one analog audio and microphone socket and a camera connection. Udoo works on 12V from an external power supply and the board has an external battery connector.

Wandboard: With 0.5GB to 2GB DDR3 RAM, Wandboard is more expensive compared to RBPi and is a unique Arduino and Linux SBC. It sports an HDMI interface, a camera interface, a micro-SD slot, an expansion header, serial port, Bluetooth, Wi-Fi, 802.11n, SATA and Gigabit LAN. This board is used in small autonomous Sumo-robots and a cluster with a custom PCI-Express carrier board adapter.

WaRP: Targeted at wearable designs, this not-yet-released Freescale supported board runs on an i.MX 6SoloLite processor based on the Cortex-A9 architecture and Android 4.3 OS. With an E-ink display and wireless charging option, this tiny board has MCU for sensor aggregation, orientation and pedometric functions. Communication interfaces include a Bluetooth wireless module, 802.11 b/g/n Wi-Fi and sports multi-chip packaging with LP-DDR2 and eMMC memories.

RIoTboard: This board also runs on the Freescale I.MX 6Solo processor based on the ARM Cortex A9 architecture. It offers very high performance video processing with HD- and SD-level video decoders and SD-level encoders. The 2D and 3D graphics accelerator are based on OpenGL ES 2.0 with shader. The Freescale Kinetics MCU is an integrated power management chip with 1GByte of 32-bit wide DDR3 running at 800MHz. The board uses 4GB of EMMC Flash and offers support for GNU/Linux and Android along with enhanced expansion capabilities.

Freedom: With ARM Cortex Core and a full tool suite, the Freedom board has up to 256KB of Flash, USB, an LCD Controller, a capacitive touch sensor, a magnetometer, a 3-axis accelerometer, a visible light sensor and a 4-digit 4×8 segment LCD.

Teensy 3.1: This is an extremely tiny board of 1.4×0.7 inches, weighing 3 grams. The ARM Cortex M4 MCU runs at 72 MHz with 256K Flash memory and 64K RAM. It is cheaper than the RBPi.

LED Light Guides Equal OLED Performance

The visual impact of OLED panels is hard to resist. Their luminosity is seductively stylish and sleek. Fashion-forward lighting designers prefer the eerily-even silky glow of the OLEDs, even though these are more expensive, have a short lifetime and can be damaged more easily than other light emitting panels. Now GLT or Global Lighting Technologies, with their edge-lit LED-based light guide technology, is about to turn the tables on OLEDs.

The latest product from GLT, a 4×4 inch LED-based light guide, demonstrates this technology specifically. Compared to an OLED panel, the GLT light guide has better durability, higher efficiency, longer life and is cheaper as well.

Applications that would normally use an OLED panel, can easily use the LED-based 4×4 inch square GLT light guide as a more durable and affordable solution. GLT has designed these light guides for use in general lighting applications and they offer diffused light output very similar to that from OLEDs, but at a much lower cost.

Offering enhanced light extraction, the light guide is very thin – only 3.5 mm. The panel itself measures only 2 mm, considerably thinner than products GLT made earlier. When in use, industry standard LEDs will typically light it up from the edges, with only a small frame concealing the LEDs. The current product gives out 250 lumens when fully powered, while the efficiency per watt is over 115 lumens.

GLT produces several types of molded light guides. All the products, including the new 4×4 backlights, are made using an efficient light extraction technology. A high-precision micro-molding process impresses optical features within the light guide. By arranging the features to provide a unique transition area, light spreads uniformly and precisely over each point across the panel. GLT has several standard patterns that they mold into the light guides. They can customize each pattern and meet any application virtually.

GLT develops their light guides in very thin packages and designs mechanical holding features into the backlights. That allows the host application to carry the entire display assembly and if that is not possible, use chip-on-flex or chip-on-glass type of assembly. That helps to reduce the parts count and material and assembly costs.

According to GTL, their light extraction technology delivers better optical performance than that offered by V-groove or stamped, chemical or laser etching and printing processes. Additionally, their process is more repeatable. After having demonstrated their light diffusion technology for a few years, GTL has now incorporated it into some of its high-end lighting products.

With their light diffusion technology, GLT offers a large variety of design options to the luminaire designers. Some of these designs can already be seen in the round 12-inch diameter pendant light. This clever design achieves results remarkably like an OLED. It uses a light guide incorporating LEDs along its inner circumference and they emit light in multiple directions.

Panasonic uses light guides from GLT in commercially available fixtures meant for mounting on ceilings. In the fixture, multiple light guides create discrete distribution patterns. These include spot lighting, downward flood lighting and upward ambient lighting within the room.

Helping Encapsulated Modules Keep Their Cool

When you encapsulate an active module, you actually cut off air from circulating and removing heat from around the components by the normal process of convection. That forces heat build-up within the active components, including some passive components as well, leading to possible premature failures. Intersil has now mastered the technology of effectively removing heat away from fully-encapsulated modules. Using their unique thermal design, Intersil is able to design very compact encapsulated modules handling up to 50A.

For example, the ISL8240 from Intersil is a 100W analog module, a step-down power supply with single 40A and dual 20A output in the same design. You can parallel up to six of these tiny modules to get a whopping 240A output. Applications involve LTE base stations and data center servers with design architectures built using several FPGAs, ASICs and microprocessors. Only 17x17mm in size, it is extremely difficult to keep the ISL8240 modules cool while delivering full power. Interestingly, Intersil has already announced another module with single 50A and dual 25A module in the same size.

The efficiency of Intersil’s thermal design was evident at a thermal test conducted with the ISL8240 module delivering 40A as output. The fully encapsulated module showed an impressive 99.6°C maximum temperature. Intersil has an evaluation board for users to try their design – ISL8240MEVAL4Z. The tests were conducted using the evaluation board at room temperature without any air flow.

The secret of the Intersil thermal design is a multilayer PC board. The trick is in placing multiple vias strategically to maximize the thermal performance. If this is done correctly, the design need not use any heat sink or fan.

In addition, the IC is mounted thermally on to a copper substrate. This allows attainment of a low thermal resistance of the order of 8.5°C/W. The multilayer board also has two internal copper planes sandwiched in between. These are connected to the top plane with multiple vias, allowing a low thermal resistance design that can remove the excess heat efficiently from the module. The top and bottom layer of the 4-layer board uses 2 oz. Copper, while the inner board layers are made of 1 oz. Copper. Intersil offers Gerber files to speed up your design time.

Intersil makes the PCBs of FR4 grade board material and copper with small additional amounts of solder, nickel and gold. The board uses vias with a finished hole size of 0.012 inches. For making a via, the initial hole drilled is of 0.014 inches. Plating adds a copper wall of 0.001 inches to the hole. Subsequently, the board is plated overall with an ENIG process, adding about 200µ inches of nickel and 5µ inches of gold on to the outer copper surfaces.

If you consider the thermal resistance of one via to that of the copper in the board layers, it will be seen that the via has a much higher thermal impedance for each layer. However, one via occupies only about 1/5000th of a square inch of the board area. The effect of placing N multiple vias in an area is a reduction of the thermal resistance by Nx times.

The Ripple Rating of a Capacitor

Engineers do not prefer having ripples in their circuits and do their best to minimize its effects. For example, an AC source delivers power to an AC-DC converter that subsequently converts it to a steady DC output. It can be very inconvenient if the output were to have any source AC power appearing on top of the DC output in the form of small, frequency dependent variations. However, ripple may not be considered evil in all cases, as some digital signals could be useful to engineers as a necessary design function. Among these are signals that use changes in voltage levels to switch the state of a device and those generating clock timings.

As capacitors can store charge, they are useful for smoothening ripples in circuits. However, the designer must take care that the peak voltage does not exceed the voltage rating of the capacitor. It must also be noted that since there can be DC bias present in the circuit, the peak voltage will be the sum of the maximum ripple voltage and the DC bias. However, that is not enough for electrolytic capacitors.

Electrolytic capacitors are usually made with aluminum, tantalum and niobium oxide technologies and they have polarity. If the negative voltage of the ripple is allowed to drop below zero, this will cause a connected capacitor to operate under reverse bias conditions. Class II ceramic capacitors used in low frequency applications also suffer from this restriction.

A capacitor functions as a charge reservoir, charging with the rise of the incoming voltage and discharging into the load as it decreases – smoothening out the ripples in the process. Therefore, capacitors will see varying voltage. Additionally, depending on the power applied, the current through the capacitor will also vary, as will the intermittently pulsed and continuous power. This causes resultant changes in the electric field of the capacitor regardless of the incoming form and creates oscillating dipoles within the dielectric material, thereby self-heating the capacitor. Any parasitic inductance or ESL and resistance or ESR contributes to the energy dissipation.

That means a capacitor with low ESR, ESL and DF (dissipating factor), will heat up less than one with a dielectric characterized by high ESR and DF. However, as these parameters also depend on frequency, different dielectric materials offer optimum performance (lower heat generation) over different frequency ranges.

The dielectric in a capacitor is usually very thin constituting only a small amount of the overall mass of the capacitor. Other materials used in the construction also contribute to the heating when considering ripple – capacitor plates being one of the major contributors. Additionally, the conductive contacts also heat up to some degree when the capacitor carries an AC signal or current.

For example, at a certain frequency, if the capacitor with a 100mOhms ESR carries a 1A rms current, the power dissipated internally will be 100mW. If this power is supplied continuously, it will heat the capacitor internally until thermal balance is reached. Since this depends on ESR, the power dissipation is a function of frequency. However, the total thermal management will also depend on the capacitor’s environmental conditions, governing the heating up of the capacitor in an application.

Pico USB Scope for the Raspberry Pi

According to Pico Technology, the beta release of its drivers for the PicoScope oscilloscopes, useful for running on ARM-based single board computers, is available. That includes development systems such as the BeagleBone Black and the ever-popular Raspberry Pi, also known as the RBPi. For the RBPi, the drivers are a specialized armhf build under the control of its Raspbian OS. Pico Technology is offering this Beta release with some caveats.

Although the developers claim to have taken care of ensuring implementation of almost all the driver features, they may not work in all cases. The developers mention that the recommended systems requirement for the drivers specifies resources that most embedded systems will not be able to fulfill entirely. That means when the system is busy, the driver may not have enough resources for processing the data, which may result in the device being dropped or the application to hang. They also expect power surges, fuse blowing and port damage and to guard against this, they suggest powering the system through a separate USB hub.

All this makes it sound like the drivers are more suitable for advanced do-it-yourself people. It also suggests that the drivers are useful for working on other platforms, but Pico may not yet be in a position to offer support for these implementations. At present Pico is focusing their support for only two platforms – the RBPi and the BeagleBone Black.

The Pico USB Scope has advanced display software that assigns almost all the display area to the waveform. Therefore, the user is able to see the maximum amount of data at a time. Additionally, this makes the viewing area much larger and of a higher resolution than that available on a traditional bench top oscilloscope.

The large display area also makes it easier to create a customizable split-screen display for viewing multiple channels or for projecting different views of the same signal simultaneously. The software is capable of displaying both oscilloscope output and spectrum analyzer traces at the same time. Moreover, the software can flexibly control each waveform individually for zoom, pan and other filter settings.

Oscilloscopes frequently require using an analog or DC offset. Most PicoScope Oscilloscopes offer this valuable feature. With DC offset, you can get back the vertical resolution, which is usually lost while measuring small signals. In practice, an analog offset typically adds a DC voltage to the input signal. This is useful if the signal is beyond the range of the ADC of the scope. By adding an offset, the signal is brought back within the range and the display can use a more sensitive range.

For testing purposes, an AWG or arbitrary waveform generator is often required. This generates electrical waveforms that can be either a single-shot or repetitive. With an AWG, you can generate any arbitrarily defined wave shape to inject into a DUT or device under test for analysis by the PicoScope. The progress of the signal through the DUT confirms its proper operation and enables pinpointing any fault inside.

Deep-memory versions of the PicoScope oscilloscopes offer waveform-buffering sizes up to 2 gigasamples, which is much larger than that offered by competing scopes of traditional bench top or PC-based design. A hardware acceleration technique ensures the PicoScope does not slow down while using deep memory and displaying at full speed.