4
WM850 High Performance Microstepping Driver
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Remark 1: Pul/dir is the default mode, under-cover jumper JMP1 can be used to switch toCW/CCW double-pulse mode.
Remark 2: Please note motion direction is also related to motor-driver wiring match. Exchanging the connection of
two wires for a coil to the driver will reverse motion direction. (for example, reconnecting motor A+ to driver A- and
motor A- to driver A+ will invert motion direction).
Power connector P2 pins
Pin No.
Signal
Functions
1
Gnd
DC power ground
2
+V
DC power supply, +24VDC
－
+72VDC
*
, Including
voltage fluctuation and EMF voltage.
3, 4
Phase A
Motor coil A (leads A+ and A-)
5, 6
Phase B
Motor coil B (leads B+ and B-)
4.
Power supply Selection
It is important to choose appropriate power supply to make the driver operate properly.
Maximum Voltage Input:
The power Mosfet inside the driver can actually operate 18V
－
+72VDC
*
, including power input fluctuation
and back EMF voltage generated by motor coils during motor shaft deceleration. Higher voltage will damage the driver.
Therefore, it is suggested to use power supplies with theoretical output voltage of no more than +72V, leaving room for
power line fluctuation and Back EMF.
Regulated or Unregulated power supply:
Both regulated and unregulated power supplies can be used to supply DC power to the driver. However, unregulated
power supplies are preferred due to their ability to withstand current surge. If a regulated power supply is used, it
should be a linear type.
Multiple drivers:
It is possible to have multiple drivers share one power supply to reduce cost, provided that the supply has enough
capacity.
DO NOT
dazy-chain the power supply input pins of the drivers(connect them to power supply separately) to
avoid cross interference. 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 improve noise,
heating and reliability. NEVER connect power and ground in the wrong polarity, it will damage the driver. NEVER
connect or disconnect the motor leads with power on to the driver.
5.
Driver Voltage and Current Selection
This driver can operate small-medium size step motors (such as low voltage versions of sizes 11, 14, 17, 23 and 34)
made by Wheeler or other motor manufactures from around the world. To achieve good driving results, it is important
to select supply voltage and output current properly. Generally, supply voltage determines the high speed performance
of the motor,
●
Selecting Supply Voltage:
Higher supply voltage can increase motor torque at higher speeds, thus helpful for avoiding losing steps. However,
higher voltage may cause more motor vibration at lower speed, and it may also cause over-voltage protection and even
driver damage. Therefore, it is suggested to choose only sufficiently high supply voltage for intended applications.
* For the European Market – the maximum input voltage must be limited to 70VDC to comply with CE regulations.
