Binzie sits atop a 25' telephone pole and rotates horizontally so that the prop is always facing oncoming wind. A scaffolding structure holds it up and also supports a work platform so that we can easily make adjustments to and inspect the windmill. A permanent ladder is in place for quick and easy ascension to the unit. The unit is grounded to help protect the windmill and barn from lightning. The actual body, props, tail assembly, and swivel unit weigh around 250 pounds total.
The props are constructed of salvaged standing seam roof tin and 1" copper pipe. Each prop is about 53" in length and each assembly consists of a sheet of tin wrapped around a spine made from a piece of the copper pipe. The three props are then connected to the hub. The face of the hub has three, 3/4" x 18" shafts welded to it (120 degrees apart) where the copper spine of each prop slides over each shaft, and the pitch of each prop can be adjusted via one turnbuckle connected from the base of each prop to the central shaft that extends horizontally to the back side of the structure. The ends of each 18inch shaft have threaded holes, where a threaded rod is inserted and runs the entire length, inside of each copper spine, so that it exits each spine and then holds each prop on via nut and large washer.
At the back of the structure are two sets of large and small belt pulleys that act as a transmission, and allow 1 complete rotation of the prop to turn an Ametek permanent magnet DC motor (generator) about 8 to 10 revolutions. This translates to a situation of when the prop is turns at 60rpm, the generator turns about 480-600 rpm. The generator begin to produce once movement begins, its output increases with speed.
Extending off of the main windmill structure is a tail constructed of 2" square tube steel and tin. This tail continually swings the main structure to rotate and always face the wind. This ability to rotate comes about as a result of a truck tire hub welded to a 8" piece of well casing that is dropped down over top of the telephone pole. The main windmill structure is fastened to this truck hub.
At the pivot point of the unit, we also mounted a power transfer collar from a silo unloader. This allows us to transfer power over the wiring paths described below, with out having to worry about wires wrapping around the pole as the windmill rotates to face the wind. The power transfer collar consists of three brass rings and a set of brushes that maintain contact with each ring as the unit rotates.
Wiring path for a Permanent Magnet DC motor-generator (current power source):
The generator has a positive and negative wire, and does not require an excitation circuit to begin to produce power. These wires are connected to two 12v lights on the windmill's tail so that it can be known when the windmill is producing power. The wires then also run down to a battery bank at the base of the windmill, with a diode assembly at the base to prevent the battery bank from actually running the permanent magnet motor (generator).
To prevent overcharge of the batter bank, we have a NC25A charge controller (found at http://www.flexcharge.com/flexcharge_usa/products/nc25a/nc25a.htm) to divert our electrical load to another power consumer (110v lights) once the battery bank is at full charge.
Wiring path for an Alternator (Previous power source) :
Initially, we used a Delco Alternator as the power source, but found it quite difficult to overcome the resistance the alternator has when producing power. When used, the main output terminal on the alternator connects to a + terminal on the battery bank, and a - terminal from the battery bank will connect to the alternator frame. The purpose of these connections is so that the battery remains charged at 12 volts, since when the windmill is working, the alternator will put out 12 to 14 volts.
The number 2 (current sensing) terminal on the alternator will connect to a + terminal in the battery bank. The purpose of this connection is so that when the battery bank is fully charged, the alternator, when spinning, ceases to put out current. This action prevents overcharge in the battery bank.
The number 1 (field current) terminal on the alternator will connect to a centrifugal switch, a resistor, and then a + terminal in the battery bank. The purpose of this connection is so that when the windmill is spinning at the proper speed, the field will become excited and kick off 14 volts of DC generation. The resistor (charge indicator lamp in a automobile and two 4 watt lamps in this setup) is in place so that the field can become excited. This resistor takes current from the battery bank and is grounded through the diode trio and subsequent diodes inside the alternator. The centrifugal switch works to hold off on exciting the field in the alternator until the windmill is operating at a speed sufficient to produce 14 volts.
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