Successful Endeavours - Electronics Designs That Work!

Electronics Design


Power Supply Specification

The idea for this post came from a discussion in IEEE Collabratec on how to design a Power Supply. The question of how to design a Power Supply seems innocuous enough until you really start to think back on past Power Supply designs. I was originally concerned that this was a student wanting someone else to do their coursework assignment for them but the discussion progressed into something quite useful. Here is what I posted after getting the following specification:

  • Output Voltage: -300VDC
  • Output current: 0.5-20mA
  • Tolerance: 30Volts
  • Input Voltage: 220-240 AC
Power Supply

Power Supply

Analysing Requirements

Hi …

is this project part of your course work?

The reason for this question is that the intent of coursework is to help you come to grips with what you are being taught and learn it from a practical perspective as well. Among other things, this helps a lot with retention.

I run a company that designs products for other people. I only employ graduate engineers who have demonstrated the capacity (though their academic results) and inclination (through their having done their own projects and learned how to use the teaching they have received) to do engineering and to be capable of quickly learning all the things they can’t teach in a course.

So if it is coursework, what subject is it part of?

Because if they want you to design a switching mode power supply, that is very different to an AC rectified transformer design.

You also need to be careful with a design assignment like this (coursework or a product that will be manufactured) because it is capable of killing you if you don’t use good safety practices.

I’ll assume your tolerance figure is +/-30V = +/-10% of -300VDC. So the voltage at its maximum excursion from 0V could be -330. And the maximum current is 20mA. This is 6.6W of power so it will get hot. And again, there is enough voltage to kill you.

If it is for a commercial product, then there are usually other constraints. Here are some of the questions I would be asking:

  • The input voltage range is specified as 220VAC to 240VAC but it is normal to allow for short term transients. So does the output voltage have to be clamped during mains transients?
  • Is soft start required?
  • How quickly must it respond to load transients?
  • What is the load and how much does it vary?
  • Does the input stage need to be designed so that it keeps harmonics and power factor under control (this is a legal requirement for some product types)?
  • Is there a maximum size?
  • What is the design life and/or MTBF (Mean Time Between Failure)?
  • Is fan forced convection allowed, and if so, is that even a good idea because of the MTBF or because it goes inside a sealed cabinet)?
  • What is the maximum temperature rise allowed on any of the outside surfaces?
  • What type of connections for the input and output voltages?
  • What has to happen if the output goes short circuit or open circuit (you had a minimum current of 0.5mA so is there a minimum external load and what is allowed to happen if that isn’t there)?
  • What is the environmental specification (0->70C, -20->85C, -40->85C etc)?
  • Is there a manufactured cost target?
  • Do you have to simulate it only, or are you building one and proving the performance?
  • Are there any special safety or EMC compliance requirements for this application?

And there are lots of other questions like this for a real product design.

So regardless of the reason for the design, understanding the intent of the exercise is important to delivering a satisfactory outcome.
This is one of the reasons engineering is not easy. We create the future. Others say that as well. But we also create the infrastructure and products that make a more advance future possible. And there are always lots of constraints.

I hope that has maybe encouraged you to think a bit deeper about the question. It is unlikely you will solve a problem you don’t fully understand. And an answer you don’t work through for yourself will probably not expand you understanding.

Successful Endeavours specialise in Electronics Design and Embedded Software Development, focusing on products that are intended to be Made In Australia. Ray Keefe has developed market leading electronics products in Australia for more than 30 years. This post is Copyright © 2017 Successful Endeavours Pty Ltd.

We Won Best Networking Implementation

You might have read our post on being finalists at the PACE Zenith Awards 2016. Tonight we won the Best Networking Implementation award for 2016. Our Congratulations also go to IND Technology. Their Early Fault Detection product was the design we won this award for.

PACE Zenith Winners 2016

PACE Zenith Winners 2016

If you are wondering what the product does, it measures electromagnetic radiation from the electricity distribution grid using custom designed antennas, does DSP math on it, determines if a fault condition such as Partial Discharge is present, and sends an alert if it detects that. It does this at 250MSPS every second and uploads the summary results to a web service. Using PPS GPS synchronisation you can determine the distance to the fault from each EFD Device. Scatter a few of these around the network and you have the most cost effective Early Fault Detection system you can get. It is also a classic high bandwidth IoT project.

OK, enough engineer speak. Here is a summary from the night.

The MC was Merv Hughes who brought a lot of humour to the night through his novel pronunciation of technical terms.

The Keynote Address was given by Dr. David Nayagam who walked us through the The Bionic Eye project and the difference it was going to make to people experiencing blindness that didn;t have underlying receptor damage.

And we had an extraordinary interlude of entertainment by the Unusualist, Raymond Crowe.

PACE Zenith Awards 2015

PACE Zenith Awards 2016

2016 PACE Zenith Awards Winners

Here are all the winners by category:

  • Safety system innovation – Robotic Automation, for Multi-product Robotic Automation
  • Manufacturing Control – Sage Automation, for Integrated Process Control
  • Automation Innovation – Robotic Automation, for Multi-product Robotic Automation
  • Transport Control – Encroaching. For POW’R-LOCK
  • Mining and Minerals Process Control – Scott Automation & Robotics, for ROBOFUEL
  • Water and Wastewater Control – SMC, for Ethercat Network for Treatment of Wastewater
  • Machine Builder – Automation Innovation
  • Oil and Gas Innovation – Yokogawar Australia, Julimar Development Project
  • Power and Energy Management – Alliance Automation, Oxley Creek Rehabilitation Project
  • Best PLC. HMI and Sensor Product – Bestech Australia, Beanair Wireless Sensor Network
  • Best Network Implementation – Successful Endeavours, IND Technology Early Fault Detection System
  • Young Achiever of the Year – Kayla Saggers
  • Lifetime Achievement – Peter Maasepp
  • Project of the Year – Yokogawa, Julimar Development Project

Our congratulations go to all the participants.

Successful Endeavours specialise in Electronics Design and Embedded Software Development, focusing on products that are intended to be Made In Australia. Ray Keefe has developed market leading electronics products in Australia for more than 30 years. This post is Copyright © 2016 Successful Endeavours Pty Ltd.

IoT Electronics

The Internet of things, or IoT, is driving semiconductor manufacturing at a faster rate than any previous technological revolution. Just last year the 2020 IoT Economy was estimated at $1T. This year, it has doubled to $2T. Here are some facts I’ve gathered about this industry.

  • 2014 – $180B in revenue
  • Today – more machines online than people
  • 2020 – $2T in revenue (eg. > Aus GDP Today)
  • Affects every economic sector
  • Peak growth year is projected to be 2016
  • Largest growth industry in history
  • Compound growth > 15% per annum

Why I am interested is that we design products that fit this category, and like any business owner, I want to understand where the market is going and what new opportunities I should be taking advantage of. As an electronics engineer I am interested in the technology itself and what design skills are needed to work with it.

It has become so important it has its own term, IoT Economy.

According to BI Intelligence IoT Report, within 2 years the number of new electronics devices manufactured for the Internet of Things will exceed all other sectors combined!

IoT Growth Projections graph

IoT Growth Projections

 IoT  Growth

So we are looking at the fastest economic growth trend ever for electronics. And there are several good reasons for this:

  • It is an essential enabling technology for Industry 4.0
  • Semiconductor device unit cost has been falling for decades
  • Processor computational power has been rising
  • Communications cost is falling
  • Power consumption is falling

This combination allows low cost, low power, communicating devices to be everywhere. In just 1 year, the projected growth doubled from $1T in 2020 to $2T in 2020.

Electronics Design for the IoT

I’ve shown an example of one driving force for IoT Growth and that is low power IoT Remote Telemetry. The Electronics Design required for this is something we are now doing every single day. Of the 20 projects we are working on right now, half of them are for the Internet of Things. In the photograph below which was taken for some for some PR for the City of Casey, every single award was for design of a device or the web services needed to support devices for the Internet of Things.

IoT Awards Successful Endveavours - Internet of Things

IoT Awards Successful Endveavours

Above you can see some of our team. The certificates they are holding are from the past 14 weeks starting with the National Manufacturing Week Endeavour Awards from the end of May.  So this is also our biggest growth area.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

Product Development

As a process, Product Development can be handled a number of different ways. And if your product only requires input from a single technical discipline which you are very experienced in, then you can usually predict everything you need to do and just make sure it all happens the right way.

But if the product is complex, involves many disciplines, and has unknowns about the technical direction to take, then it can sometimes resemble a roller coaster ride more than it does a straight forward journey. And there can be unexpected bumps along the way.

Our most recent employee brought this video to my attention and I thought it covered this topic really well. We used it for an in house lunch and learn session so I recommend you check it out to. It isn’t short so you might want to set aside a time you can sit back and enjoy it.

The presented is Andrew “Bunnie” Huang and the conference he is presenting at is linux.conf.au 2013. 

Quite a list of things you can run into just getting a fully package embedded computing device ready for market. The HDMI Man In The Middle exploit was my favourite part.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

PACE Zenith Awards

The PACE Zenith Awards 2015 celebrate the process control and automation industry’s many and diverse successes. The PACE Zenith Awards bring together some of the biggest names in Process Control, Instrumentation and Automation to celebrate, recognise and award companies and individuals for their key contribution to Australian industry. 

The awards winners were announced at the PACE Zenith Awards dinner at the Four Seasons Hotel Sydney on June 11th 2015.

This year we were finalists in 4 categories with the Power and Energy Management category having 2 projects selected as finalists.

Successful Endeavours Finalists PACE ZENITH 2015

Successful Endeavours Finalists PACE ZENITH 2015

The categories we were finalists in were:

  • Water and Wastewater – for our IoT Monitoring Platform + Telemetry Host
  • Best Fieldbus Implementation – for our IoT Monitoring PlatformTelemetry Host
  • Power and Energy Management – for our IoT Monitoring Platform  + Telemetry Host and the ABB CQ930
  • Transport Power and Infrastructure – for the ABB CQ930
PACE Zenith Awards - 5 Finalist Certificates - Successful Endeavours 2015

PACE Zenith Awards – 5 Finalist Certificates – Successful Endeavours 2015

 

PACE Zenith Awards 2015 Winners

So we didn’t win a category, but it was a great night and I always enjoy being part of celebrating what is good in Australian Manufacturing. The winners on the night were:

  • BEST FIELDBUS IMPLEMENTATION = Sigma NSW
  • FOOD AND BEVERAGE = B.-d.Farm Paris Creek
  • MACHINE BUILDER  = H.I.Fraser
  • MANUFACTURING = ANCA
  • MINING AND MINERALS PROCESSING = Sigma NSW
  • OIL AND GAS = H.I.Fraser
  • POWER AND ENERGY MANAGEMENT = Mescada
  • TRANSPORT, POWER AND INFRASTRUCTURE = Sage Automation
  • WATER AND WASTEWATER = Sage Automation
  • YOUNG ACHIEVER AWARD = Aaron Deal, Honeywell Process Solutions
  • PROJECT OF THE YEAR = H.I.Fraser

 

PACE Zenith Awards 2015

This was our first time at these awards so we learnt a lot about the process and hope to be back next year.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

Printed Circuit Board Assembly

Also referred to as a PCA, the Printed Circuit Board Assembly follows on from Printed Circuit Board Manufacture. This is where the components are placed onto the Printed Circuit Board and the electrical connections formed.

In this post I will focus on volume manufacturing techniques. We also make Printed Circuit Board Assemblies in house by hand loading very small quantities. This is appropriate for prototypes and Niche Manufacturing quantities.

To start with, lets look at the 2 types of components we most work with. The first type is the Through Hole Component. These have pins that go through the PCB to make electrical connection. These components dominated PCB Assemblies until the 1980s when higher PCB loading density requires a change of technology. They are still widely used where mechanical strength, tall components, heavy components or high current levels are involved. An example is shown below with the connectors, relays, transformers and removable components as Through Hole with the Surface Mount Components toward the centre: 

Through Hole Technology

Through Hole Technology

The second type is the Surface Mount Component or Surface Mount Device and the overall process is referred to as Surface Mount Technology or SMT. These devices do not require holes through the PCB to mount them and so can be placed closer together and it also improves track routing options because tracks can run on the other side of the PCB without having to avoid the through holes. An example of all Surface Mount assembly is shown below in close up:

Electronics Hardware

Electronics Hardware

 Printed Circuit Board Assembly Process

The infographic below was provided by Algen Cruz of Advanced Assembly in the USA. Algen also provided a brief explanation to go with it and I have added that as well. You can click on the infographic to view a larger version. 

Printed Circuit Board Assembly

Printed Circuit Board Assembly

 “Design-for-Assembly (DFA), although not as well known as Design-for Manufacturing (DFM), needs to be taken into account during the design phase. And the first step in being able to design-for-assembly is to understand the assembly process. This infographic features this process by showing how a board goes from an unpopulated printed circuit board (PCB) to a final product, ready to be packaged and sent to consumers.” Algan Cruz

 

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

Endeavour Awards 2015

This year we were finalists at the Endeavour Awards in the categories of Australian Industrial Product of the Year and IT Application of the Year. We didn’t win either category but the competition was pretty tough and I was pleased for ANCA for beat us for the Australian Industrial Product of the Year and also won the overall award for Manufacturer of the Year. The full list of winners are announced at the Endeavour Awards Winners 2015 official winners list.

Endeavour Awards Finalists 2015

Endeavour Awards Finalists 2015

It was a great night and a chance to share the evening with most of our team and a room full of people who are looking to be part of the solution rather than just contributing to the problem of being competitive in Australian Manufacturing. 

Endeavour Awards 2015 Australian Industrial Product Of The Year

Endeavour Awards 2015 Australian Industrial Product Of The Year

 

Endeavour Awards 2015 IT Application of the Year

Endeavour Awards 2015 IT Application of the Year

If you have been following us then you will also be aware we are finalists at the PACE Zenith Awards in Sydney on June 11th in 4 categories. Wish us luck.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

Printed Circuit Boards

In our series on Electronics Design we have looked at the Electronics Design Process from Requirements Capture, Technology Selection, Component Selection, Schematic Capture and finally the Printed Circuit Board or PCB Layout. Now we have a design and the Electronics CAD files to make a Prototype. 

There are a number of steps involved in making a PCB and the following infographic provides an overview.

PCB Manufacture Steps

PCB Manufacture Steps

This infographic is courtesy of Newbury Electronics.

PCB Manufacturing Problems

That is a lot of steps. And there are things that can go wrong. The main pitfalls to avoid in the PCB Design Process are:

  • track widths too narrow
  • clearances between tracks are too small
  • acute angle entry to pads
  • component footprints have pins in the wrong place or the wrong size
  • component outlines are wrong
  • silkscreen or overlay over solder pads
  • via annulus too thin
  • mounting holes in the wrong place or the wrong size
  • PCB outline incorrect
  • PCB 3D profile doesn’t fit into the intended enclosure

 And there are a range of issues that can affect the PCB Manufacturing Process. These include:

  • misalignment of drill holes to tracks to PCB outline routing
  • internal cut outs missed / not routed
  • over etching or under etching of the copper
  • incomplete plated through holes
  • poor surface finish
  • poor FR4 and copper bonding or moisture ingress leading to delamination

Maybe you are wondering how a PCB ever gets made successfully? This comes back to undertaking the PCB Design with an understanding of both electronics engineering design principles and the process capability of the manufacturer into account. And when you get it right, the final product can be pretty awesome. A good example can be found at this post about making a Fine Pitch PCB

RGB LED Array Close Up

RGB LED Array Close Up

Next we will look at the PCB Assembly process.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

PACE Zenith Awards 2015

We have only just heard. You probably already know that we are finalists for the Endeavour Awards 2015 this year with 3 of our projects. Today we got the news that we are finalists in 4 categories at the PACE Zenith Awards for 2015. I’m sure at least one of you is wondering whether I spend all my time just applying for awards. The answer is no. I didn’t even apply for these. PACE saw the entries we put into the Endeavour Awards and decided they would also be good candidates for the PACE Zenith awards and asked me if it would be OK if they entered them for us. You can guess the answer I’m sure.

PACE Zenith Awards 2015

PACE Zenith Awards 2015

As a result, we are finalist in 4 categories for the 3 projects they nominated us for. The 4 categories are:

  • Water and Wastewater
  • Best Fieldbus Implementation
  • Power and Energy Management
  • Transport Power and Infrastructure

Both out IoT Platform (Internet of Things Platform) and Telemetry Host web hosted back end qualify for all of these, and the ABB CQ930 power factor correction controller and multi-bank or multi-stage capacitor controller supports the Power and Energy Management and also the Transport Power and Infrastructure categories.

The awards winners are announced at the PACE Zenith Awards dinner at the Four Seasons Hotel Sydney on June 11th 2015.

Wish us luck.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd

PCB Layout

After the Schematic Capture component of the Electronics Design  is complete, the logical connections for the electronics components have been determined. If the Electronics CAD package also supports it, you can add rules to guide the Printed Circuit Board Layout, also abbreviated to PCB Layout which we will use from here on.

The PCB provides both the mechanical support for the components and is many cases is a critical part of the circuit since the length of tracks, their thickness, their clearance from other tracks and the relative placement of components and tracks can significantly influence the final performance of the PCB. This is particularly true as power levels, clock speeds or frequency increases.

The Electronic Schematic defines the electrical connections between components, the value of components such as resistors, capacitors and inductors, the type of semiconductors used (silicon chips) and the connectors that take signals and power on and off the PCB. Each item on the schematic has to be linked to a physical shape that will go onto the PCB. This is done by assigning a footprint to the schematic item.

Schematic Symbol

I will explain  it works. The Schematic Symbol for an FT232RL USB Serial Interface device is shown below. This is arranged with the signals conveniently placed to suit logical connections and to make the overall Schematic easy to read and understand.  The signal name is shown inside the symbol boundary, and the pin number of the IC package is shown on the outside. 

FT232RL Schematic Symbol

FT232RL Schematic Symbol

Schematic Circuit

So this  is the symbol for a single part, an IC or Integrated Circuit. The Schematic Circuit or Electronic Schematic shows the connections to the other parts of the circuit. Below we see USB connector wired up the the FT232RL IC and the power supply bypass capacitors. The logic level UART signals are shown at the top right. This section of the Electronic Schematic provides the logical connections for a USB serial interface.

FT232RL USB Schematic

FT232RL USB Schematic

PCB Footprint

 Before we can do the PCB Layout, we have to associate the PCB Footprint each Schematic Symbol will use. The PCB Footprint for the FT232RL IC is shown below.

FT232RL PCB Footprint

FT232RL PCB Footprint

This is one of the 2 possible footprints for the FT232RL. This one is a 28 pin SSOP package.

Once each Schematic Symbol has a PCB Footprint, we are ready to do the PCB Placement.

PCB Placement

 The first step is to create the outline for the PCB and its mounting points, then to place each PCB Footprint so it is in the correct place. For some components, such as connectors, there is a specific place it must go. For other components, there is more freedom to choose the position and there are groups of components that must be in a specific relationship to each other. An example of this are the power supply bypass capacitors which must go very near to the IC they are supporting.

An example of a completed PCB Placement is shown below. This is a USB to RS232 serial converter.

PCB Unrouted

PCB Unrouted

PCB Routing

Now we have the components where we want them, we turn on the autorouter and the PCB is finished. Sorry but I couldn’t help that. The autorouting features of most PCB Layout CAD software packages are never as good as doing it yourself. They can be useful for testing the ease of routing for a particular placement. There are a lot of manufacturing considerations that need to be taken into account and track size requirements, either for current carrying or voltage drop, can be hard to define from just the schematic. And example of this is the main system voltage such as VCC. In some parts of the circuit the required current is low so smaller track sizes are OK, whereas other areas need heavier tracks. It isn’t easy to define this at the schematic level because they are all the same signal or Net.

The PCB with the routing complete is shown below. The selection of track size is related to the current the circuit needs to carry. A good reference for determining the track size is provided by the standard IPC-2222A.

PCB Routed

PCB Routed

PCB 3D Cad Integration

 It is also important to make sure the PCB will fit into a mechanical enclosure. Most modern PCB CAD tools, such as Altium Designer which we use, can create full 3D models of the PCB. Shown below is an example of just the PCB without the components showing.

3D PCB View

3D PCB View

 So there we have it. A PCB taken from the completed Electronic Schematic through to a PCB Layout.

 Next we will look at prototyping our new PCB.

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

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