Originally we had the plan to the design 'an open source', to be published on the internet, so that anybody would be able to produce it in exchange for paying a small fee.

Status
On September 3 2009, we sold the technology which is implemented in the OK4All, to SMA. And we are happy we sold the technology to a solid company that can make it a success. Amongs other, this implies that it will not be an open source design. For more information download the press release about this acquisition by SMA.

Downloads - in descending chronological order

• The return of the AC-module inverter
  H. Oldenkamp, I.J. de Jong
  Paper presented at the 24th EU PVSEC, Hamburg, 21-25 September 2009
  Download (word, 598 kB)
  
• Next generation of AC-module inverters
  H. Oldenkamp, I.J. de Jong
  Paper presented at the 2nd World Conference and Exhibition on Photovoltaic Solar Energy Conversion, Vienna, 6-10 July 1998
  Download (pdf, 291 kB)
  
• AC modules: past, present and future
  H. Oldenkamp, I.J. de Jong
  Paper presented at the workshop Installing the future, 22-23 January 1998, Hatfield, U.K.
  Download (pdf, 490 kB)
  
• Nieuwe technologie zorgt voor prijsdoorbraak van OK4-100 mini inverter voor wisselstroompanelen (in Dutch)
  H. Oldenkamp, I.J. de Jong, C.W.A. Baltus, S.A.M. Verhoeven
  Bijdrage aan de Nederlandse Duurzame Energie Conferentie, 17-18 november 1997, Ede
  Download (pdf, 50 kB)
  
• Advanced high frequency switching technology of OK4 AC modules inverters break the 1 US$/Watt price barrier
  H. Oldenkamp, I.J. de Jong, C.W.A. Baltus, S.A.M. Verhoeven
  Paper presented at the 14th Photovoltaic Solar Energy Conference, Barcelona, Spain, 30 June - 4 July 1997
  Download (pdf, 105 kB)
  
• Reliability and accelerated life tests of the AC module mounted OKE4 inverter
  H. Oldenkamp, I.J. de Jong, C.W.A. Baltus, S.A.M. Verhoeven, S. Elstgeest
  Paper presented at the 25th IEEE Photovoltaic Specialists Conference, Hyatt Regency Crystal City, Washington D.C., May 13-17, 1996
  Download (pdf, 189 kB)
  
• Competitive implementation of multi-kilowatts grid connected PV-systems with OKE4 AC modules
  H. Oldenkamp, S.W.H. de Haan, I.J. de Jong, C.W.A. Baltus, C.F.A. Frumau, S.A.M. Verhoeven
  Paper presented at the 13th European Photovoltaic Solar Energy Conference, Nice, France, 23-27 October 1995
  Download (pdf, 126 kB)