Preface
My thanks to Element14 and Würth Electronik for inviting me to participate in this Energy Harvesting RoadTest Challenge.
I've already completed a large battery of tests and experiments and over the coming weeks publish my findings and progress.
Introduction
Energy Harvesting is best defined as the recovery and application of otherwise spent or wasted energy.
This energy is usually found in varying quantities in some obvious and not so obvious places.
An obvious example is Solar Energy - It's found virtually everywhere on planet Earth on bright sunny days.
A less obvious example is Thermal Energy from the difference between the ambient temperature and ground temperature.
Both are valid sources of energy that can be transformed into Electrical Energy by appropriate conversion techniques.
In my articles I will include details of odd locations and devices where I have harvested energy.
Where possible I will be using existing items and technologies in the quest for environmental sustainability and minimal impact.
And like usual I will retain the original functionality of the items.
Can anyone pick the odd picture out?
My first goal is to create a TV remote control that requires no disposable batteries. Its power will be derived from a choice harvested energies.
A TV remote control is a fairly basic device. All that happens is when you press a button a set of Infrared LEDs commence blinking in a sequence that is recognized to a TV set as a command.
It spends the remainder of its time sleeping and turns on only when a button is pressed.
A low energy microcontroller is perfect for this task.
If time permits, I will create other more capable items that operate from harvested energy and effort.
No Batteries Required.
As per usual I followed my standard strategy of Crawl, Walk then Run by familiarising myself with the Energy Harvesting Kit and conducting a large range of experiments and tests.
This kit is an absolute beauty!
It is specifically designed to expedite the development of Energy Harvesting Solutions. All of the fiddly preparation such as minute surface mount soldering has been completed allowing immediate commence Energy Harvesting research.
It comes very neatly packaged in a translucent plastic parts case that contains;
An Energy Harvesting board
And Target Load board
The boards showcase many Würth Electronik Components that are perfectly suited their intended tasks.
The components used include Inductors, Connectors, Switches, Ferrite Beads, LED and Battery Holder.
The boards also showcase Energy harvesting semiconductors from Linear Technology and EFM32 microcontroller from EnergyMicro.
The main idea is that the Target Load board can be operated from energies harvested by the Energy Harvesting board.
The boards are neatly connected together adjacent to each other making components easily accessible from the top.
The lid of the case has two apertures;
One to show the LCD display on the Target Load board
And one for the Solar Cell on the Harvesting Board.
It enables operation with the lid closed. To get it working all you have to do is take the kit into the sunlight and Hey presto - Instant Temperature Sensor Readings on the LCD Display.
(Just as you would with a Solar powered Calculator.)
The Energy Harvesting board contains four different Energy Harvesting Power supplies, a Solar Cell and Peltier Device mounted on a Heatsink.
Other energy sources can be connected via its test pins or its PiezoElectric source connector.
Unlike traditional power supplies the Energy Harvesting Power Supplies;
a. are designed to accumulate small amounts of power and then use them when enough is available.
b. be very efficient as not to waste the precious energy they have captured.
c. generate a power good signal to indicate that power is at acceptable and available.
Here is a picture of the energy storage bank.
The Target Load Board is an EnergyMicro Giant Gecko STK3700.
It an evaluation board for the highly efficient EFM32 32 bit ARM microcontroller - a microcontroller designed to operate from miniscule amounts of power.
It is perfectly suited to operate from accumulated harvested energies and periodic operation.
.... To be continued...
Please feel free to leave comments. It'll help me know what to do improve my articles.
