As cheap microcontrollers have given us an impressive range of test equipment trinkets to play with, it’s easy to forget some of the old standabys. A curve tracer for example, the relatively simple circuit allowing the plotting of electronic component response curves on an oscilloscope. Lest we forget this useful device, here’s [Gary LaRocco] with a video describing one that’s so easy to build, anyone could do it.
It’s a simple enough premise, a low AC voltage comes from a mains transformer and is dropped down to the device under test through a resistor. The X and Y inputs of the ‘scope are configured to show the current and the voltage respectively, and the result is a perfect plot of the device’s IV curve. The best part is that it’s designed for in-circuit measurement, allowing it to be used for fault-finding. There’s a demonstration at the end with a variety of different parts, lest we needed any reminder as to how useful these devices can be.
The cost of one of these circuits is minimal, given that the transformer is likely to come from an old piece of consumer electronics. It’s not the first simple curve tracer we’ve seen, but we hope it will give you ideas. The video is below the break.
