Building a simple linear power supply for a project and need to spec out a transformer. I have no idea how they're built and used in the industry. I was instead handed a 120VAC input with a 24VAC output and 2A max step down transformer. I am content with it for the moment. But I'm looking to make my power supply universal. The question is, are there step down transformers available that can handle 100-240VAC 50-60HZ inputs? Or is this feature exclusive to switching power supplies?