Spangler Prototype, Inc. (SPI)
Spangler Prototype, Inc. (SPI) has been providing solutions since 1980 in Bolingbrook, Illinois. We take pride in ourselves for providing prompt and economical design services covering a wide range of solutions from electronic flourescent lamp ballasts to inductor and transformer design. Now located in Elgin, Illinois, Spangler Prototype continues to serve, both, national and international interests.