©I.CH Motion® 2020
ichmo
.com
Specifications subject to change without notice.
Owner's Guide: 3P20M Hybrid Stepper Motor Driver
Page 8
TECHNICAL DOCUMENT
7. Connecting the Motor
The connection between the driver and 3-phase stepping motors includes two different kinds of connections, namely delta-connection and
star-connection. Using delta-connection, the performances of the motor under high speed condition are better, but the driver current is higher too
(about 1.73 times the motor coil current); while using star-connection, the driver current equals to the motor coil current.
Figure 5: Motor connections
8. Power Supply Selection
The 3P20M can match medium and small size stepping motors (from NEMA size 17 to 34) made by I.CH Motion or other motor manufactures
around the world. To achieve good driving performances, it is important to select supply voltage and output current properly. Generally speaking,
supply voltage determines the high speed performance of the motor, while output current determines the output torque of the driven motor
(particularly at lower speed). Higher supply voltage will allow higher motor speed to be achieved, at the price of more noise and heating. If the
motion speed requirement is low, it’s better to use lower supply voltage to decrease noise, heating and improve reliability.
Regulated or Unregulated Power Supply
Both regulated and unregulated power supplies can be used to supply the driver. However, unregulated power supplies are preferred due to their
ability to withstand current surge. If regulated power supplies (such as most switching supplies.) are indeed used, it is important to have large
current output rating to avoid problems like current clamp, for example using 4A supply for 3A motor-driver operation. On the other hand, if
unregulated supply is used, one may use a power supply of lower current rating than that of motor (typically 50%
～
70% of motor current). The
reason is that the driver draws current from the power supply capacitor of the unregulated supply only during the ON duration of the PWM cycle,
but not during the OFF duration. Therefore, the average current withdrawn from power supply is considerably less than motor current. For
example, two 3A motors can be well supplied by one power supply of 4A rating.
Multiple Drivers
It is recommended to have multiple drivers to share one power supply to reduce cost, if the supply has enough capacity. To avoid cross
interference, DO NOT daisy-chain the power supply input pins of the drivers. (Instead, please connect them to power supply separately.)
