Name: KB's Customized Hybrid AC Drive with power supply and elevation control was a low-cost solution for mid-range treadmill.

The customer wanted their mid-range commercial treadmills to utilize the best combination of AC Drive and motor technology.

Overview: In the application of treadmills, each of the runner's footfalls creates an instantaneous peak load on the treadmill's moving belt. The Variable Frequency Drive must maintain a smooth speed profile during these footfalls. To maintain this smooth speed profile, the AC motor speed control is required to produce high instantaneous torque with each footfall without hesitation pauses noticeable to the runner.

The application benefit: By controlling the response time of the AC induction motor with a customized Hybrid Variable Frequency Drive (VFD) designed for treadmills, a low-cost, smooth performing treadmill is achieved. The AC motor is immune to brush wear, demagnetization, and run away, and costs less than a DC motor.

The customer's product: The customer's product is a large commercial treadmill designed to be used 24/7 in health facilities.

The customer's present solution: The customer's existing treadmills are supplied with costly speed controllers using a servo-type inverter. The customer's request was for a lower cost VFD to replace the high-cost servo providing the same or improved performance.

The customer selected the KBVF-26D Adjustable Frequency Hybrid Drive (AFD) because of its ability to deliver high starting torque, quick response time with smooth, whisper-quiet operation. KB brought the customer's existing treadmill into its engineering lab for evaluation. The AC motor parameters were measured across the range of operation from low to high speeds with light and heavy loads.

KB's capabilities for solving the problem: For the Variable Frequency Drive, it's the KBVF series of imbedded drives. This series incorporates a powerful, third-generation, micro-controller that is programmable for custom OEM applications using software that has proprietary motor monitoring capabilities. KB's engineering staff has a reputation of working directly with customer applications to reach satisfactory solutions.

The KB solution: The objective was to produce instantaneous response to each footfall, smooth running operation throughout the entire speed range and high starting torque using our tried and true KBVF-26D with customized fuzzy-logic software. The KBVF software was designed to include advanced, fuzzy-logic algorithms based on measured motor parameters obtained through extensive in-house testing.

The results: Using the KBVF-26D TM Hybrid AC Drive, the treadmill had instantaneous response to each footfall with smooth running operation throughout the entire speed.

Customer's strategic advantage: The customer got exactly what he wanted - no more, no less - with a product that was customized for his application Ready to Use, "Out-of-the-Box" without any additional programming.

A Win-Win solution for both the customer and KB.