Increase Production, Reduce Costs With Joliet Technologies Variable Speed Drive Systems and Controls. Joliet Technologies is an OEM that engineers, integrates, and custom packages AC Variable Frequency Drives (VFD), DC Variable Speed Drives (VSD) and AC Drive Controllers. As a drive systems integrator, we use top-of-the-line manufacturers like ABB, Yaskawa, Siemens, WEG, and Fuji. Our custom drive packages are built to your specifications for your application, specializing in large horsepower drive systems (500 hp and above). We are also a UL 508A Certified panel shop. Serving the greater Chicagoland area and the world.