A) Mechanical Constraints/Geometry
Board Dimensions: The control board should meet the geometric constraints as defined. Geometry of the circuit board need to accommodate the concentric circular cut out inside the control board geometry.
B) Connector for the control board
Geometry: The connector can be square/rectangular in shape. The mating part for the connector can be mated with connector in only one manner/direction. The height of the connector need to be less than equal to 0.25”. If that is not achievable then the max. height should be 0.5”.
Connector Availability: Readily available connector (example from Molex, 3M etc. – TBD) – choice will be dictated by cost of the connector
Number of pins: 5 (4 inputs and 1 output)
Alternatively: No Connector on the board with wires soldered directly to the board. How much does this impact pricing? If the number of pins increase, it would be potentially more cost effective to adopt the approach of a connector than soldered wires.
C) Control Board Operation
Control Voltage: 0-5 V and PWM signal. Optional: 4-20 mA signal (optional) – dip switch
Total number of Inputs: 4 (Supply Voltage range (10 V-38 V), Common Ground, Control Voltage (0-5 V), Motor Direction of Rotation-F/R).
Discuss:+5.0V supply from board: power supply for speed control potentiometer and so the customer does not require a separate voltage source for controls.
Total number of Outputs: 1 (Tach Out) – Pulse per rev, signal options available
Motor Normal Operating Current Range: 0 – 4 amps
Motor Max. Current / startup current: 4.5 amps
Maximum electronic component temperature (ex: driver chip): max. 125 C, TBD
RPM range: 500 rpm - 4000 rpm @ given speed and given torque
Feedback: Open Loop Control with selectable closed loop control (RPM fluctuations are within 1 rpm of set point, ± 1 RPM)
Set point RPM Fluctuations at constant load: Within 1 rpm of set point, Tolerance ± 1 RPM
Motor control scheme: 0 – 5VDC PWM control signal linearly mapped to 500-4000 RPM speed. (Discuss on Open loop and closed loop with Control Resources)
D) Control Board Intelligent Protection
Over current protection: The control board shuts itself down if current exceeds 4.5 amps (Optional 3.5 amps). Reset current?
Over Voltage and Under Voltage Protection
If speed control is not required, supply voltage can be used in lieu of control voltage. Supply voltage acts as 5 V signal (10V-38V)
Thermal shutdown: Design includes thermal shutdown at 125°C. Power to be cycled after cool down below 100°C to restart
Operating Pump: -20 °C to 125 °C, 95% RH
EMC/EMI: To be designed with best practices
RoHS Compliant: yes
Safety Standards: Designed to IEC standard 60950
Assembly Standards: Built to current IPC-A-610