Can the windtura 500 be used without a rectifier to convert it to DC? What is the the AC voltage it will produce? There are grid tie inverters that have AC volts for the input.

Hi, The Windtura 500 permanent magnet alternator has been discontinued. We now only sell the Windtura 750. If I remember correctly, to get open circuit DC voltage that is rectified from AC voltage RMS, you multiply the AC voltage RMS by ~1.4. Therefore, if you want to go from rectified DC voltage to RMS AC voltage, you divide the DC voltage by ~1.4. I am not positive that this is the correct answer as I am not an EE but I do think I remember reading this in one of my physics text books years ago. If I am wrong, I am sure someone will correct me .... or give a better explanation of where the factor of 1.4 originates from. BTW, which grid ties inverters accept AC electricity? Can you provide some links?

Sun G for wind, they offered a DC or an AC. Their AC had a built in rectifier , it was the first one I owned and it worked great. I used it on a WN 500, I just exchanged it for the DC for all the different wiring option Larry and I were do for testing

Each coil in the stator creates a sine wave "AC" voltage (such as the BLACK one above). For sake of discussion, if we look at this sinewave on an oscilloscope we might measure 100 volts peak-to-peak for that coil; 50 volts below zero and 50 volts above zero. If we run this through a full wave rectifier the lower half of the sinewave flips and now it looks like a series of positive waves with a peak of 50 volts. The unfiltered DC voltage, which is the average voltage, is Vp/1.414 where Vp is 50 volts, so 35.3Vdc for this coil. Using just the 100V peak-peak then it is Vpp/(2x1.414) = 35.3Vdc. That was for just 1 phase. When a well matched simple resistor/capacitor filter is added, the Vdc can approach the 50Vdc value, perhaps a few volts below when measured with a meter. Now if we have 3 phases, as is the case with a PMA, each phase (Black, Red, and Blue above) is offset from each other by 120-degrees when rectified with a 3-phase bridge. This acts like a filter allowing the 3-phase rectified voltage to also approach the 50 Volt DC peak value as shown in the graphic. Tom BSEE - University of NY