Follow our illustrated blog on Embedded Software Architecture

How to build a hybrid solar/wind energy harvester?

The energy harvester is ready for iteration 3

Iteration 2 overview Wind power to dump load switching has been the main topic of iteration 2. In our system design we also call this Power Management Decision 1 (PMD1). PMD1 should realize several system requirements and, because we have an energy harvester model in Enterprise Architect, this list of requirements can easily be generated […]

Share

Investigating the Wind-turbine to dump load switching – part 3, other alternatives

An alternative relay we have not looked at, until now, is the latching or bistable relay. This kind of relay will only use power when changing state from open to close or from close to open. Also, it keeps its last state. Those properties could be interesting, because one of the problems we face in […]

Share

MOSFETS

In this article we are going to give a short overview of mosfets and more specifically power mosfets. Surfing the web, we found this great YouTube video (Developed under Teaching Innovation Project 10-170 of Universidad de Granada in Spain) covering the basics of mosfets: Definition “The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is […]

Share

Investigating the Wind-turbine to dump load switching – part 2, going the PWM route

In part 1, we talked about the ‘contactor’. Relays also use power, and in this particular case, the relay coil could draw up to 2 watts according to its specification. In order to save power, there are a couple of things we can do. Using PWM is one of them. Every relay coil has a […]

Share

Investigating the Wind-turbine to dump load switching – part 1

The (most obvious?) switching solution would be a high-power relay. In a previous article, we already did an experiment with a Solid State relay (and we will continue to do so). Now we will look further into the ‘contactor’. The ‘kit’ we ordered  from www.iacs.co.uk (via Ebay) is a relay board with optical isolation (to […]

Share

The energy harvester is ready for iteration 2

Iteration 1 overview Iteration 1 was mainly about extending our software platform which we call Simple Platform Abstraction. This platform enables us to easily experiment with new hardware (sensors, mosfets etc.) and will be the fundament of our energy harvester application. See the pictures for some recent hardware hacking! The software platform evolved quite a bit. We […]

Share

PMD1 sensor board: our first hardware component

We are pleased to announce the creation of our very first hardware component: the PMD1 sensor board. We won’t let you wait, here is a beautiful image: Now, let us start with the global picture. The sensor board is part of Power Management Decision 1 (see Figure on the right). PMD1 decides whether the power […]

Share

System safety: hazard analysis

Introduction The goal of each system is to perform its intended function. Easier said than done in an imperfect world, and that is what this article is about: how to design a system in such a way that the probability of hazard exposure is acceptably low. The presented techniques are well-known in the world of […]

Share

Pulse Width Modulation

A short definition Pulse-width modulation is commonly used in power-control or motor-control applications. Time is divided into periods. As always, the smaller the time periods, the higher the frequency. Within this time block a pulse signal is applied. The digital signal is logically active (“1”or ON) during a specified percentage of the time period, the […]

Share

ADC driver for the energy harvester

Introduction One of the goals of iteration 1 of the energy harvester project is to extend our software platform with drivers for measuring (gpio in, adc), controlling (gpio out, pwm) and debugging (uart). In this article our focus is set on the ADC driver (we already introduced the Analog-to-Digital-Converter here). It is hard (not to say […]

Share