Over 50 Years of Innovation

The Mark Series digital controllers were developed to precisely control Synchrotorque^® brand variable speed and soft-start hydroviscous drives. To maintain a desired clutch output condition, whether it be speed, torque (load), flow or pressure, the controller works as a closed loop feedback device utilizing the clutch output shaft controlled parameter as feedback. The input command signal is automatically and continuously compared to the output shaft controlled parameter, an error signal is generated, and the clutch clamping pressure is continually adjusted electro-hydraulically to maintain input command signal.

Philadelphia Gear released its first Mark Series controller, the Mark I, in 1969. Our engineers have worked continuously to improve the technology, and have leveraged our half-century of experience to develop the most technologically advanced version with their newest release of the Mark 8 Controller.

Below is a side-by-side, features and benefits comparison of its predecessor, the Mark VII, and the newly released Mark 8 Controller: