What happens when you put two 5.1 V Zeners in parallel? Someone told me that if the output on my Zener regulated power supply was off, doing so would help make my output closer to 5.1 V. Before I take the advice of a student, I'd like to hear it from a more experienced person from here. I am cautious, because my book neglects the subject and google finds nothing on it. This absence of information could signify unpredictability or predictably useless outputs when putting two zeners in parallel. Besides, two zeners in parallel ideally behave like two voltage sources in parallel, which is a bad thing.