Simple reverse-polarity-protection circuit has no voltage drop

摘要

Common methods of reverse-voltage protection employ diodes to prevent damage to a circuit. In one approach, a series diode allows current to flow only if the correct polarity is applied (Figure 1). You can also use a diode bridge to rectify the input so that your circuit always receives the correct polar- ity (Figure 2). The drawback of these approaches is that they waste power in the voltage drop across the diodes.