• The jumpers should be set to the default values as described below.
• Start with only the 5V logic supply (via NCS-BUS) - without applying power to the motors
and with no other connections (PC, Motors).
• Set the reference voltage for the Motor current with the R16 trimmer. The voltage can be
measured between the TEST pins. The measured voltage V(ref) depends on the motor
current (effective value) in the following way:
V(ref)=2*Squareroot(2)*Ieff(Motor)=2,83*I(Motor) equals the nominal value for the line
current. The peak current Ipeak is greater by the factor of Squareroot(2) - (max. 2,25A). For
1,5Aeff for example you would set the system to 4,24 volts.
• When all of this has been tested and verified, the board can be tested with a motor.
To do this, connect the board to the PC or microcontroller board. Always start up the PC first,
then start the software and then switch on the power supply for the board!
During boot up the power levels of some signal levels can change, that can cause undesired
reactions. For tests a free demo (for example PCNC) or a small self written program is
recommended.
If possible, start by applying a small voltage to the motor (15-20V), from a current limiting
power supply.
JP1: Step DividerJP1: Step Divider
JP1: Step DividerJP1: Step Divider
JP1: Step Divider
Jumper JP1.2 JP1.1
Full Steps closed closed
Half Steps open closed
1/4 Steps closed open
1/8 Steps open open
JP2: External rectificationJP2: External rectification
JP2: External rectificationJP2: External rectification
JP2: External rectification
The default setting (jumper set to 2-3) disables the „synchronous rectification“, and so
reduces power dissipation in the device. When no external diodes are used, change jumper
setting to 1-2. Caution: The maximum current of the board will be lowered in this
configuration!
External ConnectionsExternal Connections
External ConnectionsExternal Connections
External Connections
• The motor is connected to the screw connectors X1 (1. Coil) and X2 (2. Coil). The rotational
direction of the motor can be changed by reversing the polarity of one coil.
Center pins of unipolar motors (with 5 or 6 pins) are not connected. The pins must be
insulated and may not be connected to the positive supply or ground in any case!
Bipolar motors with 8 pins provide the possibility to connect two coil pairs in series or in
parallel. In series will always work. Connecting the coils in parallel may allow faster revolutions,
however the current is doubled as well (in comparison with the serial setup). The coil
resistance is halved in this case and the coil resistance should not be below 0.8 Ohms.
•To connect the board to the PC an interface board with a seperate connection for End-
point- and Emergency-Off-Switches is available. Alternatively an adapter cable can be used.
• When no interface board is used, pull all inputs of the board to VCC/+5V (or to ground) with
pullup resistors (10-47k).
Pinout of CON1 (NCS-BUS)Pinout of CON1 (NCS-BUS)
Pinout of CON1 (NCS-BUS)Pinout of CON1 (NCS-BUS)
Pinout of CON1 (NCS-BUS)
1not connected (n.c.)
2/Clock (Clock signal, falling edge generates a step)
3not connected (n.c.)
4/CCW (rotational direction, counterclockwise at low-level)
5/Emergency Off (at low-level)
6/Sleep (current reduction to 25% of the nominal current at low-level)
7,8 VCC (+5 Volts)
9,10 Ground
Meaning of LEDsMeaning of LEDs
Meaning of LEDsMeaning of LEDs
Meaning of LEDs
POWER: Turns on as soon as 5 Volts are applied to CON1
HOME: Lights up at every fourth full step position (Home position)
Hints for THints for T
Hints for THints for T
Hints for Troubleshootingroubleshooting
roubleshootingroubleshooting
roubleshooting
- If any part of the circuit does not work after first assembly, or when a failure occurs, find
and fix the error, before connecting or running a motor with the circuit! These additional hints
may be of help:
If these hints and the additional help at www.NC-Step.de don’t answer all your questions,
contact me for further help, by email. Please provide a detailed description of the problem
and your configuration. (Power supply, used Software a.s.o.) -> E-Mail: Ostermann@NC-
Step.de
Component List (without SMD-Parts)Component List (without SMD-Parts)
Component List (without SMD-Parts)Component List (without SMD-Parts)
Component List (without SMD-Parts)
Qty.Value Package Parts
81R R-EU_0207/10 R1, R2, R3, R4, R5, R6, R7, R8
8BYV27 BYV27 D1, D2, D3, D4, D5, D6, D7, D8
11K R-TRIMMT18 R16
1BC557B BC557B Q1
1lcLED yellow - home LED3MM LED1
1lcLED green - power LED3MM LED2
110µF/35V CPOL-EUE2.5-5 C10
1100µF/63V CPOL-EUE5-10.5 C11
1Pinh. 1*2 JP1E TEST
1Pinh. 1*3 JP2E JP2
1Pinh. 2*2 JP2QE JP1
1Connector-ML 10pol. ML10 CONTROL
2Pinhead 10pol.
3Screw Connector W237-02P X1, X2, X3
1DIL8 IC-Sockel
1DIL14 IC-Sockel
3Jumper
1TLV272IP TLV272IP IC3
174HCT14N 74HC14N IC1
0,5m ribbon cable 10pol.
Additional NotesAdditional Notes
Additional NotesAdditional Notes
Additional Notes
- A well stabilized motor voltage saves time and work, when searching for errors and reduces
noise levels. (Rule of thumb: 10.000µF for 3 motors (a lot helps a lot ;-)
- The 1 kOhm SMD resistors (R20, R21) should be adjusted according to the used LEDs if low
current LEDs are not used (Approximation: (5V - U_Diode)/I_Diode = R, e.g. (5V-1V) / 15mA =
270 Ohm).
