ElmoMC ExtrIQ Digital Servo Drives-Hornet - Manual (Page 23)

Hornet and Bee Installation Guide Installation
MAN-HRBEIG (Ver. 1.304)
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3.5. Integrating the Hornet or Bee on a PCB
The Hornet and Bee are designed to be mounted on a PCB, either by soldering the pins directly
to the PCB or by using suitable socket connectors. In both cases the following rules apply:
3.5.1. Traces
1. The size of the traces on the PCB (thickness and width) is determined by the current
carrying capacity required by the application.

The rated continuous current limit (Ic) of the Hornet and Bee is the current used for
sizing the motor traces (M1, M2, M3 and PE) and power traces (VP+, PR and PE).
 For control, feedbacks and Input/output conductors the actual current is very small but
“generous” thickness and width of the conductors will contribute to a better
performance and lower interference.
2. The traces should be as short as possible to minimize EMI and to minimize the heat
generated by the conductors.
3. The spacing between the high voltage conductors (VP+, PR, M1, M2, M3, VL) must be at
least:

Surface layer: 1.5 mm
 Internal layer: 0.10 mm
Complying with the rules above will help satisfy UL safety standards, MIL-STD-275 and the IPC-
D-275 standard for non-coated conductors, operating at voltages lower than 100 VDC.
3.5.2. Grounds and Returns
The “Returns” of the Hornet and Bee are structured internally in a star configuration. The
returns in each functional block are listed below:
Functional Block Return Pin
Power PR (Power Return)
Internal Switch Mode P.S. PR (Power Return)
RS232 Communications RS232_COMRET (J1/3)
CAN Communications CAN_COMRET (J1/20)
Control section Internal, not accessible
Main Feedback SUPRET (J2/2)
Aux. Feedback SUPRET (J1/4)
Analog input ANLRET (J2/2)
The returns above are all shorted within the Hornet or Bee in a topology that results in
optimum performance.