CLOSING THE LOOP

• Operating a Voice Coil Motor using a Function Generator
• Closed Loop Voice Coil Motor Operating Instructions
• Closed Loop Servo Motor Operating Instructions
• Linear Stepper Motor Operating Instructions

• It is important to note that servo system integration can be somewhat involved and should be completed under the guidance of an experienced servo engineer.
• •The closed loop servo diagram below outlines what components are necessary in order to have a complete closed loop system

• The stage contains the brushless linear motor and the linear encoder as well as the cable that connects the amplifier to the motor and the cable that connects the encoder to the controller.
• The controller (standalone or PC Bus), the servo amplifier (with power supply), the cable between the controller and amplifier as well as a computer must all be supplied by the user. These components may be purchased from H2W Technologies.

• In order to size the amplifier with the linear motor, the continuous and peak current, back emf (to determine required DC bus voltage) and the motor inductance should be known.
• The amplifier current controls the output motor force and the DC bus voltage of the amplifier determines the maximum velocity of the positioning stage.
• The linear motors can be used with different types of 3 phase brushless servo amplifiers (also referred to as AC servo amplifiers).

• The first amplifier type is a PWM analog input amplifier that is trapezoidally commutated using Hall Effects. For point to point positioning systems this is an ideal solution because of the lower cost.
• The second type is PWM amplifier digital amplifier that is sinusoidally commutated. It uses the Hall Effects initially to determine the commutation points and then it is commutated sinusoidally without the Hall effects. The advantage is smoother motion with lower velocity ripple
• The third type is a PWM amplifier that is sinusoidally commutated. It does not require Hall Effects but does need the programmable motion controller to do software commutation. The advantage is low velocity ripple and higher reliability due to absence of Hall Effects.
• Note, that the amplifier should be purchased with a power supply unless regulated, high power, DC is available in your system

• The controller selection is dependent on many variables and it is preferable to contact the factory and speak with one of our servo engineers.
• The contollers are available in both stand alone and PC bus configurations. They are available as single or multiple axis (up to 32 axis)