HIV (human immunodeficiency virus) is a virus that attacks the immune system, the body's natural defense system. Without a strong immune system, the body has trouble fighting off disease.
Servo-Tek Distributor: DC Tachometer Generators. A Servo-Tek DC tachometer generator provides a convenient and economical means of converting rotational speed into an isolated analog voltage signal suitable for remote indication and control. Combining high accuracy with low driving torque, Servo-Tek tach generators are ideal for use in servo systems. Tach Generators are particularly suited to application in precision integrators and velocity servos, both of which require a highly linear speed/voltage relationships with minimum ripple.
Max Ketcham. The definition of a servo drive can be found here http://en.wikipedia.org/wiki/Servo_drive In reality a servo drive controls a servo motor there are many types of servo motor from dc to ac to brushless dc. A VFD cannot control a servo motor and a servo drive cannot control a servo motor. Calling a VFD, even with add on boards, as good as a servo drive is comparing apples to oranges. They are not the same, and not meant to be used for the same type of applications.