The SMU or source measurement unit works a bit like a power supply, which can provide current to the load, and it is also a bit like an electronic load, which can absorb current from the power supply. It includes a divider circuit, so it can automatically switch between sink and source modes clean and predictable. This makes it very useful for testing various power circuits, charging and characterizing batteries, or saving bench space by replacing two separate boxes.
This DIY-SMU from analog electronics master [Dave Erikson] It is a complete four-quadrant design, which means it can work under both positive and negative voltages.The design exhibits excellent performance, comparable to costly commercial instruments, which proves [Dave]Skills and experience.
If you imagine a graph with voltage on the horizontal axis and current on the vertical axis, you can understand the quadrants. Both shafts can swing to two polarities. Quadrants I and III represent the power delivered to the load, and quadrants II and IV represent the power absorbed from the power supply.
The very detailed project log shows every bloody detail, every problem found and the work done to solve it. It is a long reading, and for those who are interested in such devices, they will spend a lot of time in the humble opinion of this scribe.
DIY-SMU is mainly analog in nature, and the control part is provided by Teensy 3.2, with Next TFT display with touch function for user interface.The firmware even supports SCPI It allows remote control and data collection via USB, so it can be placed directly into your test and measurement stack.Extra details Can be found on the project GitHub repo.
Over the years, many power projects have graced these pages, such as the 2015 Hackaday Finalist Award, but this is one of the few four-quadrant designs, so take it off!
thanks [David Gustafik] tip!