Your Questions About Wind Generators Ebay

admin answers:

Hi Yves, I’m sure there are many websites that can give you better answers so try google too, Yahoo is limited. If you look on ebay you will see lots of permanent magnet 24 volt DC motors for use in scooters, I use one of these, the 250watt model, to power a 12 volt sound system, it can deliver 10 amps at 15 volts. For a wind genny you may have to put gearing between to get the right rpm.
I don’t know if you plan to use a voltage regulator, but if you only intend to use a blocking diode, the best one is a Schottky type, there is a cheap twin 15A schottky from Maplins under £2. I use both 15A diodes in parallel so they won’t get hot & need a heatsink.
The Schottky diode has a voltage drop of just 0.2 volt, I think you put the decimal place wrong
For wind generators the recommended battery charging voltage is 13.8Vmax so 14V with the diode. Car alternators usually produce about 15 volts minus 0.6V for the rectifier, so charge at 14.4 volts. Rutland voltage regulators for wind gennies operate at 13.8volts to stop the battery over-charging.
I don’t know why charging voltages are not the same for a car and a wind genny battery, I’m inclined to think any voltage from 13.8 to 14.4 is ok.
Batteries can deliver a huge current possibly causing burns and starting a fire, so it’s essential to put a fuse in the circuit, right next to the +ve terminal is best.
Good websites are Magnificent Revolution & Cambridge Green Tech

admin answers:

Axial Flux Alternator

The axial flux alternator (sometimes called a generator), is the heart to many diy wind turbine projects. While a small permanent magnet, D.C. Motor, such as the Ametek 30, makes for a very quick and simple project assembly, these motors are becoming very difficult to find and quite expensive. Ebay is loaded with people selling D.C. Motors for home wind turbine projects, that simply will NOT work, due to the extremely high RPMs required to get any usable output. Thus a homemade axial flux alternator may be your best alternative.
What is an Axial Flux Alternator?

A permanent magnet alternator generates power by passing magnets past a group of coils of wire. The magnetic field that surrounds a magnet is call it’s flux. Axial Flux simply means the lines of magnetic flux that past through the coils of wire, travel along the “axis” of the turning motion. The other type of magnetic flux in an alternator is called RADIAL FLUX and it occurs when the flux occurs “around” the magnet. Pictures are worth a thousand words:

Radial Flux

Axial Flux Alternator

In the left picture, the yellow disk is the stator. The two bluish plates rotate, along the horizontal axis, past the stationary stator. In the image to the right, the stator is on the case. The rotor, on the axis, rotates “inside” the stator. This guide by Hugh Piggott describes the process in good detail – How Axial Flux Alternators Work

Overview of the Complete Process – Building an Axial Flux Alternator

In February 2001, Hugh Piggott created a guide for building a permanent magnet generator (PMG) (alternator), after being commissioned by the British government. This guide remains in the public domain and provides an excellent overview of the complete process. You can build a PMG from these plans, though these instructions continue to be improved upon. The PDF document can be downloaded here: PMG Manual

This manual describes how to build a ‘permanent magnet generator’ (PMG). We can
also call it an ‘alternator’, because it generates alternating current (AC). Continued…