I am replacing a DC power supply used in a lab experiment. We need to be able to choose a positive or negative current. Bipolar power supplies in our power range (around 1 kW) are expensive, so I am planning to buy two separate units: a unipolar supply, and another unit that will allow us to switch between the two polarities.
What is the name of that second component? Can I reasonably expect to get both from the same supplier?
Best Answer
A DPDT (double-pole double-throw) switch or relay can be used to reverse polarity. In some circumstances an H-bridge can be used.
Note that if your supply has one side (perhaps the negative) grounded it may not be useful to reverse the polarity since that side will remain grounded.