Its very difficult to explain the concepts of power and energy. People often ask me “Can I power my kettle with that?”. So to try and put the energy in a cup of tea into perspective I built the ‘Cuppa-meter’. The ‘Cuppa-meter’ shows a cup of tea which lights up as the energy required for … more

Low-Cost Wind Datalogger

Wind speeds are very site-dependant – with topology, ground roughness and other factors affecting the local wind speed. Knowing the wind speed and frequency of the wind speed at a particular location allows us to make a more accurate resource assessment. An accurate resource assessment is required for ensuring the wind turbines are sited correctly … more

Latrine Logger Prototype

I have been working along with Nicola Greene (in conjunction with Water for People and Engineers Without Border UK) and James Fowkes (a fellow Nottingham Hackspace member) to look at the issue of data monitoring for pit latrines. A group of us had a hackday at Nottingham Hackspace to discuss the problem, look at solutions … more

Pedal power for Nottinghamshire Healthcare

There has been a spate of pedal power projects in the re-innovation workshop recently. This post shows one recently built for Nottinghamshire Healthcare. The pedal generator was designed as a challenge with a twenty second test to see the amount of energy the cyclist can generate. It also needed to be relatively portable (to fit … more

Pedal Powered DVD

I’ve just put the finishing touches to a pedal-powered DVD player which will be installed at a Stubbington Study Centre in Hampshire. This pedal generator is designed to be entertaining and fun, while also being educational and robust. There are three parts: Pedal generator – based on an exercise bicycle Large bar graph display DVD … more

PV I-V Curve Tracer

It is very useful to measure the current against voltage characteristic for a solar photovoltaic panel. Here I shown how I built an I (current) against V (voltage) curve tracer for solar photovotlaic panels which is battery powered and can be used ‘in the field’. The output is displayed on a full colour LCD display, … more

Charge Controller Project – Voltage Measurement

Measuring voltage is required for the open charge controller project, as we use the voltage to measure the charging of the battery. Hence we need to be able to reliably and accurately measure voltage. I have written quite a bit before on voltage measurement. Here are the details on measuring voltage specifically for the open … more

Charge Controller Project – Kit

Note (9/10/13): This is a work in progress and there are no kits available yet. Please watch this space or email us if you are interested. Here you can buy a kit of the open-source charge controller. This includes all parts and a pre-programmed microcontroller. Full instructions for making your kit are available here. If … more

Charge Controller Project – Heatsink

The open-source charge controller circuit contains a diode and a MOSFET, which could potentially have up to 20A flowing through them. In this case they will get hot and will eventually fail. We need to ensure that they will be kept within their specific working parameters by keeping them cool. This is done with a … more

Charge Controller Project – Power Supply

Here we discuss options for providing power to the circuit itself. The input from the renewable energy source will be variable and the input voltage will vary. We need to provide power to the microcontroller ‘brains’ of the device. This requires 5V DC. Hence we need to efficiently step down the voltage from the input … more

Charge Controller Project – Power Switching

Within the open charge regulator we must control power, either to limit the power flowing into the battery or to control the power flowing to the dump load. This requires some kind of power switching. This article explains the different types o power switching available to us and the decision on which type of power … more

Charge Controller Project – Microcontroller

The open-source charge controller project will be based upon a microcontroller. A micro-controller is basically a small computer. It can be programmed with code which will run when the device starts up. The control program will be programmed onto the microcontroller. Using a re-programmable microcontroller means we can upload different code to perform different functions. … more