I looking to buy an electromagnet (12v) and there are a lot of them out there on amazon and ebay in all kinds of size and shapes -some are round, some are rectangle, etc. However, in my application, it's important that I have a positive side of the magnet facing out when the current runs through the electromagnet. In my application, I'm utilizing the repel effect of two magnets where another piece has a permanent magnet with positive side facing out. So the goal here is that when the electromagnet is energized, we have a force that pushes the two magnets away from each other.
For example, in this picture with this DC electromagnet, is it as easy as changing the polarity of positive and negative to get, say the positive side on its face? The specs that I ready don't mention anything about that. Thanks in advance.