Here on this Link is an selfmade PID Servocontoller for brush Servomotors whis encoder, for HP or Agilent Encoders, an works whis 200-1000 Step encoders
The circuit make maximum 80V and 25A for the Servomotor, and is verry easy an stable
The circuit has an Clock and and direction input, an can connect to par port of an PC.
Basis is an Atmel Controller, and the cost including the programming = 20Euro
The Hex File is not only avaible
The Rest of Matterial is < 20 Euro
http://5128.rapidforum.com/topic=112...267&startid=23

Servo motor diskussion is on this link
http://5128.rapidforum.com/topic=112282918267