How to acknowledge funding
If I write is supported by, I give the impression that I am currently being paid


"Work by this author was partially supported by the Hitchcock Institute and by the Norman and Norma Bates Foundation."


  if I write partially supported I give the impression that I just got a smaller grant


Nonsense.  Unless the institute was your sole source of income and equipment during the entire research and writing process, "partially supported" is correct.  Also, it's standard idiomatic language; nobody will think twice about it.