Report KD 797 can be copied for free from my website at the menu KD-reports. The title of this report is: “Calculations executed for the 3-bladed rotor of the VIRYA-4.1S windmill (lambda design = 4.5, stainless steel blades) driving the PM-generator of Magnetic Innovations type 260-75 LS for water pumping or grid connection or the type 260-75 HS for 48 V battery charging”.

Chapter 7 of report KD 749 about water pumping with the VIRYA-5S has been completely reviewed. Figure 7 has been added.

Report KD 796 can be copied for free from my website at the menu KD-reports. The title of this report is: “Ideas about a 20-pole radial flux permanent magnet generator with a 3-phase, 1-layer winding with no iron in the coils”. Report KD 645 about a 10-pole generator is cancelled.

Report KD 437 about the VIRYA-15 has been reviewed. The curve e = 0.75 L has been added in figure 8.

Report KD 793 about the VIRYA-3.2 is replaced by report KD 794 about the VIRYA-3.6. The title of KD 794 is: “Calculations executed for the 3-bladed rotor of the VIRYA-3.6 windmill (lambda design = 4.75, stainless steel blades) driving the PM-generator of Magnetic Innovations type 260-25 HS for 48 V battery charging” or water pumping. The reason is that it was expected that the torque level of the chosen generator allows a larger windmill rotor resulting in a maximum electrical power of about 1 kW at V = 10 m/s.

Report KD 792 about the VIRYA-4S is replaced by report KD 793 about the VIRYA-3.2. The title of KD 793 is: “Calculations executed for the 3-bladed rotor of the VIRYA-3.2 windmill (lambda design = 4.5, stainless steel blades) driving the PM-generator of Magnetic Innovations type 260-25 HS for 48 V battery charging”. The reason is that I could borrow a generator with the frame size which is used for the VIRYA-3.2 and that I have performed some measurements at this generator. The measurements are given in chapter 9 of KD 793.

At 11-3-2026, report KD 793 was completely reviewed. The rated wind speed was increased from 9 m/s up to 10 m/s. The Q-n curves for short-circuit and for 52 V star are now derived from the measurents for short-circuit as given in chapter 9.

At 12-3-2026, chapter 8 of KD 793 was extended. Apart from a winding with six coil bundles of five coils now also the option of three coil bundles of ten coils is described. This appears to be the configuration of the real winding which is shown in the photo of figure 7.

At 13-3-2026, the estimated peak torque of the generator was reduced from 95 Nm up to 75 Nm.

Report KD 792 can be copied for free from my website at the menu KD-reports. The title of this report is: “Calculations executed for the 3-bladed rotor of the VIRYA-4S windmill (lambda design = 5, stainless steel blades) driving the PM-generator of Magnetic Innovations type 260-75 HS for 48 V battery charging”. The compact radial flux generator of this wind turbine is originally used as a fan motor. At 25-2-2026, a new chapter 7 has been added to KD 792. The title of this chapter is: “Simplification of the spoke assembly”. The triangular sheet is now cancelled. At 27-2-2026 a new chapter 8 has been added to KD 792. The title of this chapter is: “Description of the generator winding”.

Report KD 750 about the VIRYA-5R with a 2-bladed rotor made out of Roofmate is cancelled because it is doubted if the rotor can be made strong enough. The new report KD 791 is added titled: “Calculations executed for the 3-bladed rotor of the VIRYA-5B3S windmill (lambda design = 6.5, Gö 711 airfoil, stainless steel blades) meant for connection to the axial flux generator of Hefei Top Grand type TGET450-5KW-300R for grid connection or water pumping”.

At 16-3-2026, chapter 7 of KD 791 about water pumping with the VIRYA-5B3S was completely reviewed.

At 27-3-2026 a new chapter 7 is added to KD 791. The title of this chapter is: “Use of the VIRYA-5B3S for 144 V battery charging”. Water pumping is now described in chapter 8.

Report KD 377 about the pendulum safety system has been reviewed. The design wind speed Vd has been reduced from 7 m/s up to 6 m/s. Chapter 6.3 describes now an alternative with two rotors. At 26-2-2026 a new chapter 7 has been added to KD 377. The title of this chapter is: “The delta-V curve for whole numbers of V”.

Report KD 772 about the VIRYA-10S with a 3-bladed rotor with stainless steel blades is replaced by report KD 787 about the VIRYA-10B2 with a 2-bladed rotor with wooden blades. The title of KD 787 is: “Calculations for the 2-bladed rotor of the VIRYA-10B2 windmill (lambda design = 7, Gö 711 airfoil, wooden blades) using the hinged side vane safety system and a generator type TGET770-H-10KW-100R for grid connection”. It is expected that manufacture of hollow stainless steel blades is too difficult for most companies and that manufacture of two wooden blades is easier.