Bipolar Power Supplies Run The Voltage Gamut

In a previous article, I wrote about generating negative voltages via a standard unipolar dc power supply outfitted with polarity-reversal relays (see “Turn Positive Voltages Negative With Relays”). This method works well for certain applications, namely those requiring discrete test conditions that are sometimes positive and sometimes negative.  For such applications, polarity-reversal relays offer an inexpensive way to generate the …