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Solar energy – generation & applications – AC vs DC

‘High Voltage’ – transmission & usage

Following on from our recent post on our Solar Power System – On Grid Project, the observation has been made that it’s rather inefficient to generate power as DC electricity, and convert it to a higher AC voltage, before converting it back again to DC to suit many consumer applications.

The issue of use of AC or DC is not a new one. Famously, in 1893, Thomas Edison who promoted the generation and use of DC ‘lost’ the battle to George Westinghouse who gained acceptance for the generation of AC at the Chicago World’s Fair, since it was more efficient in long-distance transmission.

This has been the situation for more than a century and still applies with generation at remote power stations and transmission at high AC voltage to feed and satisfy local demand. The 240V (in the UK) AC mains electricity that is delivered to a household is perfectly suitable in this form for domestic high power applications i.e. cooker, washing machine, etc. On the other hand, electricity is used for variety of low-voltage DC devices and gadgets e.g. phones, TVs, computers and so on, contain power adapters converting AC to DC and stepping down to typically 12v or 5v USB. Lighting is traditionally AC, but with advancement in LED technology could be of a lower DC voltage.

The development of locally generated solar energy changes things somewhat. The generation output is low voltage DC. The majority of this generated electricity is utilised locally. Excess energy can be stored in batteries, which are also low voltage DC. This could be used in this form, but in order for a household to be able to supplement locally generated energy, when the sun doesn’t shine (night time / winter), it still has to be wired to receive AC from the grid-based electricity. Also, to facilitate the export of excess energy (an increasingly valuable benefit of domestic solar power generation), the locally generated electricity must be converted to grid-compatible AC, using an inverter.

It should be the case that houses of the future are designed and built with solar panels on the roof. Indeed, it is now the case they are cheaper that slate, and so the materials and labour charges would be negligible costs if part of the build rather than as an add-on. In which case, the building could be designed with 12V DC and 5V USB supplementary to the 240V AC for mains wiring, feeding appliances directly at the type of voltage they require, eliminating power rectifiers and most voltage converters.

This ‘direct supply’ is already demonstrated in our Solar energy off-grid eBike charger project with the generated supply connected to a AA / AAA / C / D / PP3 battery charger using its 12V DC input (bypassing a 240V AC input, which requires internal conversion). The 12V supply also feeds LED lights without voltage conversion.

Charging batteries from 12V DC Solar Energy

Similarly, the 5V USB outputs of the solar charger controller can charge iPhones and other gadgets.

Solar Charge controller with 5V DC USB sockets

‘Highway to Hell’ – EV charging & V2X

We know that Electric Vehicles (EVs) are going to be increasingly in use and will gradually take over from petrol and diesel engines.

And so the ability to charge these at home will be increasingly important and convenient. Some cars are already of a Plug-in Hybrid Electric Vehicle (PHEV) type, meaning that they can be charged from a domestic UK 240V AC supply for local use.

Another key development is the concept of EV batteries being used as supplementary storage for a household, so called ‘Vehicle to Home’ (V2H), ‘Vehicle to Building / Business’ (V2B) or ‘Vehicle to Grid’ (V2G) [collectively V2X indicating bi-directional, as opposed to single direction V1G], charging at low demand and discharging when household usage is greater, or to take advantage of higher export pricing.

The AC supply is needed to be converted to a DC voltage useable by the car batteries, and similarly the car’s electricity needs converting from DC to AC for household export. There are two ways of achieving this, by having a converter in the charger or the car. But if the premises has its own source of accessible DC power, ideally sourced from locally generated solar energy, then this conversion would be unnecessary.

Another issue is that UK 240V AC is limited to 13A supply from standard household sockets (for most domestic use) providing slow charging at 3kW. A dedicated charging point using a UK Type 2 connection is an improvement with direct connection to the mains consumer unit, providing charging at 3.6kWh from a 16V AC supply or 7.4 KW from a 32V AC supply. Faster charging is possible with 11kW from 32A AC supply or faster still with 22kW from 63A AC supply, but these are more expensive, beyond the available power of many households and require a 3-phase supply.

The European Union has specified the Combined Charging System (CCS) standard to permit both AC and DC charging. Much faster and more efficient charging at 100kW and beyond is possible using DC charging, eliminating the conversion in the vehicle. However, this is currently an even more expensive solution and limited to EVs that can accept a compatible DC input. Charging at commercial sites such as motorway service stations offer a variety of standards, including the CCS (Europe), CHAdeMO (Japan), GB/T (China) or Tesla Supercharger (propriety).

EV charging service station offering both CHAdeMO and CCS standards

This conversion and compatibility issue is not confined to motor vehicles. As highlighted in the Solar energy off-grid eBike charger project, conversion using an inverter is necessary from the 12V DC power generated from the Solar Panel and stored in the battery, to 240V AC used by the required charger, which then converts again into 36V DC. The problem is not just related to type and size of voltage, as the lithium batteries used require special adapters to perform the charging correctly. It would be possible to produce these fed from a specialist DC adapter, but such chargers are more difficult (and expensive) to obtain, given that the domestic supplies are generally not available in this form and so consequently the demand for these products is not yet there.

‘Thunderstruck’ – Solar powered cooling (mini project)

Given the current heat-wave and the likely-hood of more temperature extremes as a result of climate change, coupled with cost-of-energy crises and possible supply shortages, it seemed appropriate to build another solar power project, this time focusing on powering a cooling fan with energy from the sun.

The concept is relatively straight-forward: using solar energy to assist with cooling. When sitting out and the sun is shining and the temperature is too hot, the sensible thing to do is shelter under some shade. But when there is little-to-no breeze, even in the shade it gets too hot to bare. In which case, a simple fan can help. The one selected was an old, cheap USB model, which provides a limited amount of cooling, but doesn’t require much energy to operate. Also chosen was a small, also old, and low-cost 6V solar panel, which provides just enough energy to power a USB device using a suitable conversion lead.

But this isn’t particularly robust since a slight drop in sunshine can stop the set-up working. Hence this has been additionally paired with a battery power bank, which can simultaneously be charged with the solar energy whilst also powering the fan.

Naturally, the battery pack can be charged separately – ideally powered by locally generated and stored solar energy!

Charging the battery bank from solar energy

‘For those about to Rock’ – the Electric future

Hopefully this has been food for thought into the exciting fast developing world of solar power generation and the electric future. Please get in touch if you have questions, comments or ideas to share.

@YellowsBestLtd our mission is in “Keeping Customers Operational”. We’re always keen to enhance our range of #business services, increase the #enterprise infrastructure we support and expand our mix of #sustainable solutions we offer for supply and maintenance of new and legacy #technologies and products for our customers.

Please help us understand your management services or solutions requirements, whether you’re implementing new systems or maintaining existing infrastructure networks to serve your operational business needs.

Solar Power System (on-grid) project

‘Free’ electricity from the sun

Obtaining low-cost renewable solar energy has always had much appeal, but historically the investment costs has been rather off-putting, especially in the U.K. where it is perceived that the climate doesn’t provide a reliable enough amount of sunshine.

However, in recent years a number of things have changed this evaluation. Performance improvements in solar panels and associated power inverters have resulted gains in energy creation, coupled with the availability of modern battery arrays substantial enough to store the energy produced for later reuse. At the same time, shocks to world fuel prices have results in a rapid shorting of the ‘payback period’; once it was considered that a typical household solar installation would take in the order of 25 years to recoup the investments costs. This has tumbled to around an estimated 8 years based on calculations made last year, and taking into account the recent price increases for domestic electricity supply, the period could be approaching 4 years with further shortening likely as energy prices continue to rise. The recent removal of VAT by the UK government on the implementation of solar energy systems is an added boost.

One additional further benefit that has recently arisen is the introduction by some power utility companies, such as Octopus Energy, of ‘agile’ export tariffs, which pay increased amounts at peak demand times. This can be taken advantage of by the use of smart meters, supplying surplus generated or stored energy to the grid at the best times to maximise revenue, offsetting the purchase of electricity from the grid at other times.

Given that the future is anticipated to require increasing use of electricity to provide power for EV cars and hybrid vehicles, generating your own electricity makes increasing sense.

Overview of our implemented system

Given the now obvious benefits of a solar energy, we have acted accordingly and implemented a system, which has the following component parts:

13x 385W JA Solar Monocrystalline Panels with PERC technology, limited by the available roof space, but sufficient for energy needs.
Alumero Mounting accessories & Tigo Optimisers to enhance performance when part of the solar array is shaded.
Luxpower Hybrid Auto Inverter, 16A single phase, to convert the generated 12V DC electricity to 240V AC for household consumption or export.
4.8 kW Aoboet Uhome battery storage array to store excess energy for later use.
AC and DC isolators to connect the component system parts.
Generation meter to measure energy production.
Wifi Monitoring portal for displaying instantaneous and historical performance.

The calculated annual yield for this system is 3,679kWh, which should be enough to fulfil the household’s electricity needs, estimated at 3,207kWh based on previous usage.

Solar Panels – the ‘heart’

Key to the collection of energy from the sun are naturally the solar panels. These vary in size, and technology is improving continuously, so the latest available are more efficient than previous generations.

Those selected for this project were 13 x 385W JA Solar Monocrystalline Panels with latest PERC (Passivated Emitter and Rear Cell) technology. Monocrystalline are more expensive but more efficient, with a longer lifespan than other types available. PERC technology improves light capture near the rear surface, optimising electrons flow and thereby achieving higher efficiencies.

The amount produced by a solar array naturally depends on sunlight hours and will be much lower with poor weather or as daylight reduces, whilst household electricity demand also varies during the day.

The ultimate aim of using solar power is to reduce as far as practically possible the need to source energy from the grid. Consequently, a larger array of modules than those just to meet the typical usage amount is needed to ensure adequate production whatever the weather, with the excess being stored or exported.

Alumero mounting kits were used for fixing the solar panels to the property roof, together with Tigo optimisers which maximise the generation from each panel. Without such optimisation, the power output from all solar modules can be reduced when some of the array is in shade.

DC Isolators

DC isolators connect two ‘strings’ of series connected panels to the Hybrid Inverter.

Hybrid Inverter – ‘the brains’

In order for the system to be truly useful, power conversion and energy management functions are needed, to ensure a seamless and uninterrupted supply of electricity from the available sources i.e. an appropriate mix of the local generation, storage and grid supply. Chosen for this installation was a Lux Hybrid Automated 16 Amp single phase inverter.

The Hybrid Inverter ensures that when solar energy is available i.e. during daylight hours, this is firstly routed to provide for domestic consumption, and then used to charge the battery storage (as required, if not full). Any additional energy is exported to the external grid. When there is not enough energy generation from the solar array, the hybrid inverter routes the energy storage to the household, and when this is depleted, electricity is imported from the grid in the usual way. Critically, where to source electricity from is completely seamless such that the domestic consumption is never interrupted and the household is unaware of these ‘decisions’ being made.

It’s the inverter’s job to take the DC electricity produced by the solar panels and turn it into 240V AC electricity for household use. It’s a sad fact that many domestic appliances then take this 240V AC and convert it back to DC and lower voltages like 12V and 5V; this double conversion adding theoretical inefficiencies. But this is simpler to implement than rewiring the entire building and trying to then integrate with power to and from the grid.

AC Isolators connect the Inverter’s output to the household electricity supply.

Batteries – ‘the memory’

Quite literally, ‘saving for a rainy day’ is the function of the batteries, which add to the capability and capacity of solar power generation. They are effectively ‘optional’ since the system can be run without them. But since there is a huge natural variation between maximum sunlight and night-time, it makes sense to capture excess energy at peak times, and use this when sunlight is not available or sufficient.

Chosen for this project were 2x Aoboet Uhome-LFP 2400 providing 4.8kW of storage capacity.

At the beginning of a day, the batteries are naturally somewhat depleted, and therefore excess solar energy is initially used to charge them. Once full, they remain ‘on standby’ until later when generation is unable to fulfil the immediate electricity needs, in which case they start discharging their stored energy. Ideally, they will not become completely depleted over the course of the day and night, so that energy is not needed to be imported from the grid.

Grid – import / export

Electricity from the grid is the “insurance” for times when the solar energy is not able to fulfil demand. Naturally, this is likely to be due to a lack of winter daylight hours and/or poor weather, which of course has to be paid for.

Generation Meter

But at other times, there will be an excess of energy that can be exported to earn back some of these costs. A Generation Meter as part of the solar energy system enables this export of electricity.

Smart Meter

WiFi Monitor

The bi-directional energy flow is measured with a ‘smart’ meter using a suitable import / export tariff from the Utility company, such as the Octopus with their Agile tariff, and displayed on an associated WiFi monitor.

As to be expected, the amount paid by the Utility for kWh export is considerably less than that charged for import, so it’s worth making best use of the generated and stored energy as much as possible, like running appliances when the sun shines!

An EPS (Emergency Power Supply) socket was additionally included in this project. Though optional, it was chosen for providing ‘backup power’ from the solar energy system in the event of a power outage from the grid supply. It is standard practice in such an event to shut off the export to the grid from solar energy systems to avoid difficulties whilst restoration work is in progress. But during such a period, the household can make use of the generated and stored local energy, for a limited time and restricted to a maximum of 13A. Avoiding excessive consumption, it should be possible to maintain a local supply for 12 hours, assuming a fully charged battery array.

To complete the project to become an ‘energy generator’ (as well as satisfying own consumption needs), an MCS (Microgeneration Certificate Scheme) certificate is issued, together with receiving acceptance documentation from the DNO (District Network Operative). This then allows the establishment of the export tariff with the Utility provider so that payments for excess energy exported will be made.

Operating performance

A WiFi Portal provides the householder with an overview of the current operation of the solar energy system, displaying instantaneous status and historical energy performance for tracking generation yield and import / energy export.

Initially, it can be reported that average energy yield is around 0.86kWh, ranging between a typical peak of 2-4kW during the day and zero at night, compared with average consumption of approximately 0.35kWh, with the excess charging the batteries in the morning and exporting to the grid during the rest of the day. During the night, the consumption is met from the battery storage, with the batteries depleted to around 11% by the next day. It is noted that even during relatively cloudy days, at least around 10% of the 5kWh maximum power is generated, enough to at least meet the immediate consumption needs and even provide some battery replenishment.

A complete picture of the operating performance of the solar energy system will be known after a full year, taking into account the peak of summer and the shortest winter daylight period. Rising costs of electricity will also impact on the longer-term cost savings anticipated.

Conclusions

Hopefully this ‘project description’ is of interest and perhaps of use to anyone contemplating installing a Solar Energy system at their home or office premises. Please feel free to get in touch if you would like us to provide consultancy advice (on a no-obligation FOC basis) leading to a quotation for establishing your own system, or just to gain an in-depth appraisal and more information from our first-hand experience of implementing a Solar Energy system.

Our summary of conclusions at this stage having now implemented a system are:

Solar energy collection has developed rapidly in recent years, particularly now that home energy storage is practical enough to capture excess energy during peak daylight and release it for use during the night or whenever demand exceeds generation.
Although such systems are still a significant investment, given the recent escalation in energy costs, the ‘break-even’ point has reduced dramactically and the trend is for energy costs to continue to rise thereby making the payback period increasingly shorter.
An attractive feature is the notion of being paid to supply energy to the grid, though it should be noted that currently at best this is 7.5p per kWh, so unlikely to be a significant revenue source. But it does mean that energy bills over the longer term will be vanishingly small.
The contribution to the nation’s renewable energy mix helps in a small way to aid the drive to reduced carbon emissions and tackle climate change.
Naturally, a suitable oriented roof or land space for solar panel installation is required, as well as a location for housing the inverter and batteries (loft space is ideal). Plus, it should be noted that a PV cable needs to be installed (most likely running down the outside wall of the building) to link the inverter to the consumer unit.
Should power cuts from the grid occur in the future, the solar energy system is capable (thanks to the EPS socket) of providing power for a limited period to maintain household electricity use.
With the increasing use of electric cars (all new will need to be at least hybrid by 2030), being able to source local renewable energy will make increasing sense.

@YellowsBestLtd our mission is in “Keeping Customers Operational”. We’re always keen to enhance our range of #business services, increase the #enterprise infrastructure we support and expand our mix of #sustainable solutions we offer for supply and maintenance of new and legacy #technologies and products for our customers.

Please help us understand what would be of interest to you by getting in touch to discuss your management services or solutions requirements, whether you’re implementing new systems or maintaining existing infrastructure networks to serve your operational business needs. We look forward to hearing from you.

Sagem ADR SDH family

‘Legacy’ telecoms history

The Sagem ADR product range was an SDH Add-drop Multiplexer (ADM) product family designed as a flexible platform for Metro Access and Metro Core, backhauling, microwave radio and Utilities infrastructure networks.

The family included ADR155c and ADR622, STM-1/STM-4 ADM, and ADR2500 ‘eXtra’ and ADR10000, STM-16/STM-64 multi-service NG SDH. This range was managed by the IONOS Network Management System (NMS) which also managed Sagem Primary Multiplexers, PDH and SDH microwave radio and DWDM systems.

The ADR family was deployed worldwide with more than 60,000 units over 5 years.

Comprehensive Functionality

The ADR platform offers a large variety of interfaces from E1 and E3, Fast Ethernet and Gigabit Ethernet, enabling the provision of a wide range of end Customer services. Transmission protection for guaranteed QoS is provided with SNCP, MSP, MS-SPRing as well as common unit and tributary protection.

The STM-16 network units can be used for multi STM-1 or STM-4 and local-cross connect functionality thanks to a fully non-blocking switch matrix.

The modular and flexible housing provided by the ADR155c (2U), ADR622 (6U) and ADR2500 ‘eXtra’ (14U) 19” and ETSI subracks provide a flexible mix of office, street cabinet and equipment room deployment.

Continuing to provide operational service

The ADR family of SDH products continues to provide operational service with various global Operator, Utilities and Transport companies.

@YellowsBestLtd supports requirements to maintain these networks by supplying various spare part items from refurbished and surplus stocks in perfect working order.

There follows a list of the main elements that are typically provided, though other items can be provided. Please let us know of any specific requirements you may have. We look forward to being of assistance.

SAGEM ADR Spares List

Part Code	Unit type	Description
AM101333 / 251 119 665	ADR155c	A155 BLK STM1/4 21E1 19″/ETSI CORE CHASSIS
AM101330 / 251 137 402	ADR 21E120	ADR BLK BNC 21E1/120 ITFE CARD
AM101328 / 251 137 366	ADR IC1.1	A155 BLK FC/PC IC1.1 OPTIC STM1 CARD
251 137 410	ADR LAN1	A155 BLK ADRLAN 10/100BT ETH ITFE CARD
AM101360 / 251 131 182	ADR FAN	FAN MODULE
AM101670 / 251 137 431	ADR ERE	A155 BLK BNC ELEC STM1 ITFE CARD

The ‘Banana Phone’ reloaded …

Communicating, or stuck in The Matrix?

The original Nokia 8110 ‘slide’ mobile phone was immortalised in the film ‘The Matrix’ in 1999.

Back then, people used mobiles for mostly … calling people, and the occasional text message. Ok, and a few plays of the game ‘snake’!

It was affectionately referred to as the ‘banana phone’ due to its unusual curved shape, though the only colour you could get it in was black.

Since then, we have had a revolution in data networking and an explosion of app-based touch-screen smartphone slates. So much so that people are finding themselves addicted to looking at these personal pocket computers ‘all the time’.

Consequently, there is now a growing trend of wanting a ‘digital detox’ and to get back to basics with a simple, cheap device that keeps you in touch without taking over your life.

The updated Nokia 8110 4G ‘Banana’ phone

In 2016, HMD Global Oy took over the licence to produce Nokia branded phones, and have since been revisiting and refreshing classic designs including their take on the ‘slide-phone’ with the 8110 4G.

As well as traditional black it’s available in bright YELLOW, making it this time the true ‘banana phone’.

With a design that harks back to those simpler days, it never-the-less comes with a number of advanced features.

What’s Good: Simple ‘Real’ number and calling keys for phoning and familiar ‘Nokia’ menu structure providing Call log, Contacts, SMS. Twin SIM cards for 4G calling flexibility at home and away. WiFi. Removable micro SD-card for expandable storage. Replaceable battery. Music Player, FM Radio and headphone jack. Camera, gallery and video player. Internet Browser and e-mail. Flashlight, Notes, Recorder, Calculator and Unit Converter. Clock and Calendar. Google Maps and directions.

What’s not-so-great: No touch-screen! Small display. Minimal App support. Fiddly ‘old school’ text-entry. Slow and limited internet capabilities. Low-resolution imaging and video, and no front-facing 2^nd camera. Cursor keys surprising small and tight to bottom of display making scrolling more awkward than it ought to be. Having to take the battery out to insert / remove the memory card.

What’s Fun: Answering calls with a slide (and end them again by closing. Freedom from ‘smartphone’ addiction, though if you really must, WhatsApp, Twitter, Facebook and Youtube can just about be used. And ‘snake’ (though a strange ‘modern’ version), plus some other games and more can be downloaded.

In summary, this is a feature-packed but ‘basic’ mobile which brings an iconic design up-to-date, is fun to have, does the basics and a bit more.

Keeping connected with a digital detox

This Nokia ‘featurephone’ doesn’t pretend to rival ‘smartphones’ in capabilities. But useful as a supplementary device in case of a flat battery, and good for just keeping connected while getting on with life. Handy too when wanting to avoid carrying a very expensive piece of hardware when active or travelling.

There has been a trend to have just one device with as many functions as possible packaged in, with inevitable strain on battery life. It can however be sometimes preferable to use a Hi-Res player for music, a quality camera for photography, a tablet for internet browsing and a phone for – phoning!

So not a complete digital ‘detox’, rather just providing another alternative option to keep ‘plugged in’ to today’s ‘Matrix’ world of communications.

Your technology experiences

If you have fond memories of past technologies, views on future trends or experiences to share on managing your digital life, please get in touch. We’re keen to discuss how we may be of assistance in developing your business and keeping your new and legacy systems operational.

Nokia 8110 4G: YellowsBest would be delighted to hear from you!

Operational Technology (OT) vs Information Technology (IT)

OT and IT: What’s the Difference?

Information Technology (IT) is a familiar concept to most modern office workplaces encompassing the products and networks providing data-centric computing, supporting various business functions such as finance, personnel, management and administration. This has grown to being fundamental to corporations large and small, and continues to rapidly develop in scale and capability.

By contrast, Operational Technology (OT) is understood by utilities, transport, manufacturing and other industrial sectors, as encompassing an array of systems engineering, event monitoring and process control to facilitate operations. Historically, the technologies and products used to implement the required infrastructure have been bespoke and separate from other corporate systems.

The growth of standardisation

With the explosion of computing devices, the internet and communications generally, the underlying IT hardware and software have become ubiquitous and standardised. The majority of businesses now deploy products and networks which are interchangeable with most other global corporations, bringing overall costs down, increasing ease-of-use and enabling global inter-operations.

In recent years, there has been a trend to capitalise on these developments by seeking to replace old OT bespoke systems with widely available and deployed IT products.

The problem with convergence

Despite the advantages brought by a move to using IT technologies to fulfil Operational infrastructure needs, there are some draw-backs.

Although no-one wants systems to fail, and high performance is often a key requirement, in traditional OT systems, there is an emphasis on availability, reliability and ‘mission-critical’ operations, dictating deterministic technologies which standard IT products are not designed to provide. The packet-oriented ‘best-efforts’ nature of TCP/IP networking solutions is not sufficient to provide the performance required. Some operational systems have specific timing requirements, utilising PDH and SDH TDM-based technologies to deliver signalling and tele-protection information.

For years, ‘security’ against ‘remote attacks’ was not an issue, because most OT systems were regionally based and not connected to the wider world. And even those with remote monitoring and control tended to use bespoke equipment which was not widely understood or utilised by non-specialists. With a move to going ‘on-line’, and utilising ‘standard’ IT equipment to fulfil OT requirements, this is no longer necessarily the case. Which brings the possibility of outages due to system or denial of service attacks. ‘Cyber-security’ in recent years has needed to become part of the considerations for OT infrastructure, learning from the experiences of threats to IT systems and ‘denial-of-service’ attacks.

And whilst modern IT communications bring gigabit data bandwidths, OT data needs have remained modest, often to fulfil the unchanged monitoring requirements for an enormous existing deployed network of slow-speed kilobit data devices, such as pumps, valves and actuators.

In short, the needs and desires of businesses for computing devices, networking systems and global communications to provide ever-increasing bandwidth and application support continues to diverge from the requirements of industrial operations, requiring availability, compatibility and mission-critical performance.

Future trends

Whilst vendors of networks, computing and communications continue to develop advanced technologies to meet the growing needs of IT for businesses, the desired ‘convergence’ to replace OT systems continues to be a work-in-progress.

OT systems tend to be built with longevity as a priority over cost of ownership, due to the challenges of replacement once in continuous operation. Whereas IT products are often ‘written down’ and replaced over a much shorter timescale, with a view to taking advantage of continuous developments to provide higher performance and productivity.

Consequently, technologies that are considered ‘legacy’ by IT professionals continue to be maintained and even further deployed as trusted and proven OT systems to fulfil operational needs.

Your operational systems requirements

@YellowsBestLtd would like to know your infrastructure goals, deployment experiences and maintenance challenges and how we may assist you to fulfil your OT and IT requirements, for both new and existing operational systems. We look forward to understanding your needs for technical support, solutions sourcing, repair services and equipment spares.

New and Legacy communication issues

Challenges with maintaining Legacy systems

It can make perfect sense to continue to run existing reliable and proven systems, especially if operational requirements have not changed. Alas, the developing nature of technology means that from time-to-time, issues arise.

Changes to email encyption protocols

Modern computer communication services support the Transport Layer Security (TLS) encryption protocol. This aims to protect the information sent and received over a standard Simple Mail Transfer Protocol (SMTP) connection between two computers while ensuring that they both agree and understand the method of data transfer.

However, the earlier versions of TLS 1.0 and 1.1 have been deemed by the industry to be not secure enough and have been superseded by versions 1.2 and 1.3. You and/or your service provider may have already transitioned to the latest protocols. However, if you have old hardware running legacy software, as support from service providers is withdrawn, you may find your email stops working.

How you can tell if it’s an issue

If you’re using an Apple Mac then the Safari Browser has supported TLS 1.2 for web traffic protection since version 7 in 2013. However, if you’re still running ‘El Capitan’ OSX 10.11 with Apple Mail 9.3, it won’t support TLS 1.2 for email. Other computer hardware and software combinations may also run into problems.

Most browsers including Safari ended support for TLS 1.0 and 1.1 in March 2020, and various service providers have either already dropped or soon will withdraw operation of the older TLS protocols.

For instance, one.com will stop support of TLS 1.0 and 1.1 on 17^th August 2021. Other service providers may have different end of life dates. If you’re using the one.com service then there’s an easy way to check:

send an email to:

protocol@tls-check.one.com.

This will provide an automated reply telling you what protocol you’re using (works with iPhones and iPads too), like this:

{
            “started”: true,
            “protocol”: “TLSv1.2”,
            “cipher”: “ECDHE-RSA-AES256-GCM-SHA384”,
            “keysize”: 256
}

Other service providers may have similar methods of verifying the protocols, so it’s worth checking with them. Failing that, you may be able to examine the headers of your emails, to look for something like this:

version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128

Solutions if you’re affected

To ensuring your email continues to function, the options include:

Updating your operating system. In the case of Apple Mail on Mac computers, this means moving to ‘Sierra’ OSX 10.12 as Mail cannot be separately upgraded.
Using a different email client with TLS 1.2 support, e.g. Mozilla Thunderbird.
Using a browser based solution for your email
Changing your settings to send and receive email without encryption (not recommended)

Balancing New Requirements and Legacy Support

If you want to stick with your current hardware and software choices, this does present a problem, particularly if you’re otherwise happy with your setup and are unable to upgrade.

Alas if you want full compatibility (and security) with the latest industry supported functionality, whilst retaining operation of other legacy applications, consideration has to be made to invest in new hardware to run in parallel with older systems, which continue to be maintained to perform dedicated compatibility functions.

YellowsBest: Keeping Customers Operational

If you have similar or other new requirements and legacy maintenance needs, please get in touch to discuss how we may be of assistance to keep you operational.

Challenging times demand time for a change!

New “UK” launch

It’s been a challenging time for businesses generally, and particularly in the United Kingdom, with Brexit in many cases adding cost and time to trading, and Covid-19 restricting travel and networking.

So it seemed an appropriate time to launch a new varient of the Yellows Best Limited website, now additionally utilising “.co.uk” as a signifier of commitment to our home market location.

Keeping Customers Operational

The new YellowsBest.co.uk promotes the same blend of Services and Solutions for “Keeping Customers Operational”, but presented in a different and modern single-page layout, making it particularly mobile device-friendly where ‘vertical scrolling’ is more appealing than using the traditional ‘horizontal tabbed’ layout.

We hope this provides Customers old and new with a welcome alternative, though the original YellowsBest.com will continue to be maintained, along with it’s associated blog for ‘informal’ views and news updates.

Assisting with your requirements

It would be interesting to receive feedback as to how useful you may find this additional site, and whether there is anything else you’d like to see featured.

Of course, @YellowsBestLtd online content ultimately serves the purpose of highlighting the types of services and solutions we can provide. Customers may therefore be prompted to get in touch to discuss their specific requirements, which we can usually assist with.

Rest assured, if you use either contact address:

enquiries@yellowsbest.co.uk

enquiries@yellowsbest.com

we’ll receive your message and will be in touch by return. We look forward to hearing from you!

eTrike Conversion Project

More fun going electric

With the combination of moving to a more sustainable future along with a fitness drive encouraging people to be more active, one thing growing in popularity is the “eBike”, which supplements the efforts of the rider with a low speed assistance from an electric motor.

This means you don’t need to be young or super-fit to enjoy getting out and about, with good speeds and longer distances very achievable. And if you want a challenge, you can always switch the assistance off!

Ebikes come ready built to ride away, but an existing machine can be converted.

The three-wheeler challenge

Given the benefits to two-wheeled cycling from going electric, a similar upgrade to an existing 3-wheeled recumbent trike was called for.

eTrikeOriginal — eTrike awaiting conversion

In principle, this is ‘simply’ a matter of adding an electric motor and a battery, which is indeed what was done, but there were a few challenges along the way.

Step 1: choosing the electric motor location

The first major decision to make when converting or purchasing any electric cycle is the location of the motor; there are three options: front-wheel, rear-wheel or bottom-bracket mount. For the Trike, with its two small forward wheels, front mounting is not possible. The rear option would require the replacement of the wheel with one with a hub motor, and anyway this can be considered an inferior location given that the motor drive is separate from the rider’s push of the pedals.

Consequently, a bottom-bracket motor was selected, which confusingly on a recumbent trike is not a ‘centre mount’ because it is located at the front, ahead of the front wheel.

Step 2: Motor selection

There are now an expanding number of manufacturers of electric cycle motors, but some of these are only built into new bicycles, and others are prohibitively expensive kits. However, some very affordable Chinese products are available via AliExpress. The selection of the Tongsheng 36V 250W Tsdz2 model from pswpower was made.

Given the restriction in the UK of a maximum speed of 15.5 mph for powered assistance and limit of 250W, this unit is perfectly adequate for the intended task.

Step 3: Bottom Bracket ‘special’ fit

The ‘Bottom Bracket’ is the place on all cycles which enables the pedals to rotate, with bearings facilitating the movements of cranks. However, there are many ‘standards’ of different manufacturers models, so getting a motor to fit in place is not necessarily straight-forward. The existing Trike had what is known as an Ashtabula or ‘American’ one-piece crank’ (OPC) Bottom Bracket, whereby the cranks for the pedals on each side are formed from a single unit and uses a 51.3mm bearing cup pressed into the frame.

OnePeiceCrank — American style one-piece-crank

Unscrewing the crank retaining nut was aided by use of a Park Tool HCW-18 spanner. One of the pedals was taken off, the bearings teased out, and the crank fed out. Then a brass drift punch bar helped to hammer out the mounting cups from each side.

The difficultly then came that the mounting shaft of the Tsdz2 motor is smaller than the bottom bracket diameter, and is also offset. Fortunately, there is a perfect conversion solution to this problem already available, called the Eccentric BB adapter. This converts the Ashtabula empty shell to standard BSA size 34mm diameter (68mm width), but also is asymmetrical mounting which perfectly accommodates the offset motor shaft. This though is somewhat tricky to source; eventually located at Luna Cycle in CA, USA.

eccentricBBadapter — Eccentric BB American to BSA adapter

Fitting the adapter required careful insertion either side, being a close fit and needing gentle assistance with a mallet, also ensuring that the rotation of two halves lined up.

But once fitted, the motor was slid in and the offset mounting ensured that the shaft located without difficulty or fouling of the frame. The retaining bracket was fitted to the motor and secured with two M5x16 bolts, and then the M33 retaining nut was screwed into place and tightened using the special ring spanner tool supplied with the motor.

The fixing block was then attached with an M8x40 bolt, and the motor assembly secured in place using the bridge-plate, needed to prevent the possibility of the motor rotating in the crank when being powered in operation.

Step 3: Cranks and pedals

The cranks then fitted to the motor spindles either side. The supplied 170mm long parts were too long for the recumbent machine, being designed for a standard bicycle, and hence a pair of 152mm cranks were sourced, which matched the length of the original ones, which being an all-in-one unit couldn’t be reused. Neither could the pedals, which were a different screw size, and so standard gauge replacements were fitted.

These feature a reverse thread for the left-hand side, which therefore was secured by anti-clockwise rotation, whilst the right hand naturally secures clockwise.

Step 4: Battery fitment

Next came the addition of the 36V 13Ah Lithium-Ion power source. There are various types that can be used on standard bicycles, including down-tube or top-tube units, and bottle-type, but the recumbent trike doesn’t have space for any of these. Instead, it was necessary to add a rear carrier, mounting over the rear wheel, to house a rack mounting battery purchased through eBay from 167-tradeworld-uk. This wasn’t a completely straight-forward fit, as first the rear axle position had to be slightly centralised to accommodate the brackets, and then 16mm pipe clips were needed be added to the frame behind the seat for attaching the front stays to secure the rack. This ensured that the rack didn’t slide or rotate forwards or backwards in use with the weight of the battery.

With the rack secured, the purpose-built battery housing was screwed in place on the lower row of the carrier. Then the battery was slid into place and secured with its key lock. Charging of the battery can be made in situ, though it can also be removed for this purpose. This was fully charged using the dedicated mains / 36V power supply adapter.

Step 5: Display mounting

An important part of the electric conversion system is the incorporation of a display, which connects the power and controls the cycling assistance, whilst also providing useful data such as speed, distance and charge remaining.

For this project, a VLCD5 display was chosen, ideal for the purpose. Due the limited room and mounting options, given that there are no high up handlebars or top tube on the recumbent trike, the display was mounted centrally on the low steering crossbar. This was secured via the two horizontal attachment loops, thus in use being positioned between the rider’s legs.

The optional remote button control was additionally located on the left handle grip, though this was subsequently found to be of no practical use in operation.

Step 6: Wiring up

With all the main components in place, all that was left was to make the various wiring connections, starting with linking the battery to the motor. The battery came with an XT-60 socket, whereas the motor has 4mm bullet connectors. Also, due to the forward mounting location of the motor, a cable of approximately 1m was needed to link the parts, converting the connection types in the process.

Next, the speed sensor was fitted to the left-hand rear wheel stay and accompanying magnet to the spokes, by means of cable ties. This is the means by which the control unit calculates and therefore displays the speed and distance travelled.

The attached cable contains a splitter which is used to connect to both the display unit and also optional front and rear lights. Chosen for this purpose was an AXA Echo 15 switch for the front, and a Lynx rack mounting e-bike red LED for the rear, both of which fortunately accepted the 2.8mm mini spade connectors on the wiring harness.

This combination cable was again too short to link the display with the sensor, so an additional 1m speed sensor extension N58B cable was added, this having the required 6-pin male/female connectors to plug into the splitter cable and the corresponding motor connection.

Step 7: Powering up and Configuring

The final step was to switch on the battery using the key and control panel with a press of the power button, and then set about configuring the system parameters.

The wheel size was set to 20 inches, and the distance measurement to miles. The i-button on the display module cycles the modes from ODO (total distance), TRIP, AVG (speed) and TIME. The +/- buttons increase/decrease the selected assistance level from ECO (minimum), TOUR, SPEED to TURBO (maximum).

The front and rear lights can be switched on and off with a short press of the power button. The rear battery light can be additionally manually switched on.

A long press of the power button switches the display off.

Finishing up and testing

To finalise the build, some cable sheaths were added to tidy up the wiring, and cable ties secured all the leads. The original flag (useful for visibility for such a low-down vehicle) was cable tied in position against the rear rack.

The eTrike frame was adjusted for the right seating position. Now was time for a test ride!

The completed machine performed perfectly well, providing, as most electric cycles do, assistance from a stationary start up to the legal maximum of 15.5 mph. Pedalling effort is still required by the rider, but the effect is to ‘flatten’ hills (and reducing the need for gear changes), making the experience less strenuous and more enjoyable, maintaining a greater average speed and achieving longer ride distances.

In conclusion, the eTrike conversion was relatively straight-forward, once all the necessary component parts had been identified and sourced. Since recumbent trikes are a somewhat specialised form of cycle, and tend not to be alike, then it is to be expected that a degree of customisation is required to achieve the build of a suitable electric conversion.

Your transformation projects

@YellowsBestLtd assists customers in developing their business and improving and maintaining their infrastructure. Should you have any requirements or plans, please get in touch to discuss how we may be of assistance.

Mobile Evolution and the Extinction Event

When Giants ruled … mobile communications

A long time ago, great “Dinosaur beasts” of Mobile Communications were supreme. The beginnings were in the 1970’s with the launch of a Motorola handset weighing 2kg. This was followed by other barely portable products with huge batteries such as the Nokia Talkman. Only for the ‘new adopters’ who had to be in touch all the time.

Then came the ‘Bricks’

From these humble beginnings, soon a range of solid, reliable but ‘bricklike’ big and heavy phones appeared, like the Nokia 2110 and the Motorola Dynatac 8000X, as featured in the 1987 movie “Wall Street”. Designed for upwardly mobile business people.

Diverse expansion

Then came a period of rapid expansion with a diverse range of more affordable products to suit wide consumer tastes. Various forms, colours and accessories became more and more important, with slide phones like the Nokia 8110 as featured in the 1999 film “The Matrix” and flip phones like the Motorola Razr, providing a ‘Star Trek’ appeal.

Feature explosion

An expansion of more and more features to make mobiles do more fuelled the explosion of product ranges. Cameras and music players were added to increase the functionality of these increasingly sophisticated and compact pocket-sized devices, such as the Nokia 6230.

A glance at the 2004 Carphone Warehouse catalogue shows how varied mobiles had become, with the top 10 dominated by Nokia, Sony-Ericsson, Siemens and Motorola as the biggest manufacturers of the time.

‘Tyrannosaurus’ functionality heavyweights

For a while, the king of the land was the bulky, terrifyingly expensive but impressive (for its time) Nokia Communicator, offering phone, text, email and even fax. Opening up to reveal a full QWERTY keyboard, the range started with the 9000 which appeared in the 1997 film “The Saint” and had evolved by 2007 into the even more powerful E90.

LegacySmartPhone — Nokia E90 Communicator

Extinction Event: The Death of the incumbents

But then came biggest shock to the world of mobile communications: the launch of the first Apple iPhone on 9^th January 2007.

Like a meteorite striking the earth, this shock spelt the end for many mobile types which couldn’t compete with the sudden demand for ‘touch-screen’ devices using apps.

Indeed companies like Nokia, once the biggest of them all, couldn’t adapt and died a death, as well documented in the BBC documentary “The Rise and Fall of Nokia”

Survival of the fittest

The ‘smartphones’ from Apple and later Android-based from the likes of Samsung became an increasing hit, wiping out much diversity and seeing a seismic shift away from many form factors to the now standard “slate” style of device.

Some ‘featurephones’ as they came to be known have lingered on, and in recent years companies like HMD global, who under licence have taken some iconic Nokia designs such as the 3310 and made a successful relaunch. Diversity is now finally creeping back with new variants such as the ‘folding’ Samsung Galaxy Z Fold2.

Your Paradigm shifts

Any memories or stories to tell? @YellowsBestLtd would be keen to hear your thoughts and experiences of sudden technology ‘paradigm shifts’. Let us know if we can be of any assistance with your future solution or services requirements.

Legacy Transmission & Line Codes

Before Fibre, there was copper!

It’s almost difficult to believe that not so very long ago (ok, going back maybe more than 50 years) there were no optical fibre or digital transmission paths of any flavour of technology providing our communications infrastructure.

Analogue FDM

From early to mid 20^th Century, an extensive core copper cable network was rolled out, based on analogue FDM (frequency Division Multiplexing) over coaxial pairs, with the valve-based technologies occupying a lot of space and consuming much power.

Digital PCM

The late 1960s saw the introduction of digital PCM (Pulse Code Modulation) sampling at 8kHz. The ITU-T (International Telecommunication Union – then known as CCITT) standardised 30-channels at 64kbit/s in a 2.048Mbit/s multiplexing system, using 8-bit A-law algorithm (the USA adopted 24-channel 1.544Mbit/s with μ-law algorithm).

Problems with high bit-rates

The higher bit rates gave rise to crosstalk interference problems on many existing cables. Also, data signals transmitted as voltage levels in unipolar NRZ (Non-Return to Zero) format are not self clocking and have a significant DC component, wasting power. Bipolar RZ (Return-to-Zero) type AMI (Alternate Mark Inversion) coding prevents the build up of the DC-component for longer distance and addresses the issue of data containing multiple ones. However, long sequences of zeros still present problems with a lack of transitions causing difficulties maintaining synchronisation.

Introduction of Line Codes

Line Coding of the format mB-nB was introduced to overcome these issues. Initially 4B3T (four Binary, three Ternary) was used. This encodes each 4-bit input group into a 3 symbol output using the three states of positive, negative and no pulses.

e.g. ‘0000’ is coded as ‘+0-‘

This improved efficiency in terms of bit per symbol over AMI, which itself is an example of a 1B1T code. Improvements in transverse screened cables were also made. However, transmission problems with high-speed digital data were still encountered due to unsuitable copper cabling which needed to be addressed.

PDH Higher Order Multiplexing

By the late 1970s, the UK had adopted the ITU-T recommended PDH (Plesiochronous Digital Hierarchy) of E-carrier higher-order multiplexing at 8Mbit/s, 34Mbit/s (in the US, T-carrier at 6Mbit/s, 45Mbit/s) and 140Mbit/s.

The lower rates of the E-carrier system adopted HDB3 coding, which replaces 4 ‘0’s with ‘000V’ or ‘B00V’ (or in the US for T1, B8ZS coding which replaces 8 ‘0’s with ‘000VB0VB’).

CMI (Coded Mark Inversion) was included in the ITU-T standards for higher-order PDH at 140Mbit/s PCM (as well as SDH at 155Mbit/s electrical STM-1). This is a 1B2B type of NRZ coding where a ‘0’ is represented by ’01’ and a ‘1’ as an alternatively ’00’ and ’11’, with +V and -V representing the coding levels.

The advantage of the coding is it makes clock recovery by the receiver simple and for maintaining synchronisation alignment with a long sequence of ‘0’s or ‘1’s.

Optical fibre systems

From the beginning of the 1980s, early optical-fibre multi-mode systems operating at 850nm were deployed, and later single mode at 1300nm, using the PDH multiplexing capacities.

Typical of long-haul PDH optical-fibre systems, the 2 Mbit/s, 8 Mbit/s and 34 Mbit/s ‘Dynanet’ products from Nokia have ITU-T G.703 compliant digital interfaces using the HDB3 code, but using an optical transmission Line Code of 5B6B. This is another type of mB-nB code, where in this case 5 bit data words are coded using 6-digit code words

e.g. ‘00000’ being represented as ‘100111’.

As well as its use on electrical systems, CMI Line Coding has also been popular for use on short-haul optical-fibre transmission such as ’tactical’ fibre optical systems operating at 2 Mbit/s.

SDH / SONET – A different approach

For optical SDH systems, STM-1 and above, scrambling is employed instead of line codes to ensure the incoming bit stream contains sufficient transitions for maintaining synchronisation. This works by combining the data signal with a pseudo-random bit sequence generated by a scrambler polynomial generator.

i.e. with a sequence of length of 127, the generating polynomial is 1+x⁶+x⁷, leading to input data ‘00000000001111111111’ being scrambled as ‘11111110000001000001’.

Optical PDH still serving

In most cases higher-order optical PDH has been decommissioned, but optical transmission at 2Mbit/s is still in operation for many low-data rate applications, where costly replacement with SDH, WDM or carrier Ethernet would bring no advantage. An example product is the Nokia DF2-8 which continues to offer reliable access services, particularly in the Utilities and Transportation industries.

Copper systems still in operation

Though core copper electrical transmission systems have now been discontinued, much of ‘last mile’ telephony and related broadband connections are still copper access. For extended data transmission applications, copper systems are still deployed and maintained. Such products include the Nokia DSL2i copper line equipment (including power feeding repeaters) using SHDSL (Single-pair High-speed Digital Subscriber Line). This uses TC-PAM (Trellis-Coded Pulse-Amplitude Modulation) which is a 4B1H Line Coding, since translates 4 binary digits into 1 Hexadecimal (16) levels. It improves range, especially when used with regenerative repeaters, and improved ADSL (Asymmetric Digital Subscriber Line) compatibility.

Feedback and assistance

This has been a necessarily very brief run-through of legacy transmission and some of the Line Codes employed. @YellowsBestLtd would be keen to hear your experiences and knowledge of transmission systems and performance of Line Codes. If we can be of any assistance with your solution requirements, including both new and legacy technologies, then please get in touch.