Constant Current Load
The client required a high accuracy constant current load which was rugged enough for Industrial applications along with having common components that can be easily sourced even in remote locations. The board needed to be repairable by unskilled technicians at remote locations.
This device was to be capable of up to 15A of current and dissipate up-to 200W heat with a fan cooling. The system can work up-to 35V and needed to be capable of high side regulation without accurate ground reference.
For ease of repair the first part was to avoid SMD components and for the same reason microcontrollers were out of the question. The board needed to be completely analog with high redundancy which was done by giving each mosfet a driving IC.
An additional logic was implemented to send out an alarm in case the input power supply dipped below the current setpoint of the system. We also supported the client in low volume production of the system in a ready to install configuration.