Power Supplies & Accessories

Though most stepper and servo drives sold by Servo2Go® are full-featured, often the unique requirements of an application require accessories to optimize the system.  We carry a variety of power supplies to power your servo or stepper drive.  Sizes range from 300W continuous to over 35kW peak power.  Selecting the correct power supply is as simple as specifying the correct voltage and picking a model that can supply enough power . In addition to voltage and power, isolation is a very important consideration.  For safe and reliable operation, either the drive or the power supply must have isolation.  In the drive, isolation takes the form of optical isolators that isolate the signal ground from the power ground.  In the power supply, isolation takes the form of an isolation transformer that isolates the input AC from the power supply output. If the drive datasheet does not specify optical isolation then you must use a power supply with an isolation transformer.

To ensure current loop stability, a minimum load inductance is essential for the proper operation of PWM servo drives.  If the load inductance is less than the minimum rating for the servo drive, Filter Cards can be used to add inductance to the motor/drive system.  For example, if the servo drive datasheet calls for a minimum inductance of 250uH, and your motor only has 25uH, then the addition of the BFC15030 will ensure proper operation.  The total inductance for the motor and filter card will be 25uH + 300uH = 325uH.  Inductive filter cards are also used to reduce the PWM switching noise that occurs with high power supply voltages (>250VDC) and long cable runs (>10m).   FC filter cards are designed for use with brush type servo motors, voice coils and other single phase loads.  BFC filter cards are designed for use with brushless servo motors, linear motors and other three phase loads.

Transient over-voltage problems are quickly solved using Shunt Regulators.  These simple devices increase system reliability by stabilizing voltage fluctuations thereby eliminating over-voltage shutdowns.  The need for a shunt regulator is indicated when system faults occur during the deceleration portion of a move.  This can be verified by monitoring the power supply voltage on an oscilloscope and looking for voltages that exceed the over voltage rating of the servo drive.

Many motor and drive systems require a Regen Clamp circuit to limit increases in power supply voltage when the motor is decelerating under load.  This is commonly referred to as "regeneration", and occurs when DC motors are driven by their load (backdriving).  During regeneration the DC motor can produce enough voltage to actually exceed the input power supply voltage.  Applied Motion drives can deal with regeneration by channeling the increased motor voltage back to the source power supply.  However, if the voltage is not clamped to a safe level the power supply and/or drive can be damaged or destroyed. 50 Watt continuous, 800 Watt peak rating.