Among the potential fault conditions that must be considered when designing the DC
power port for portable electronics are incorrect voltage power supply connections (user
error) and dirty power supply connections. Lack of adequate port protection can result in
customer dissatisfaction and expensive warranty returns.
The most cost-effective way to implement a power bus for portable electronics is with a
standard DC barrel jack. However, because this connector is so commonly used, the user
may accidentally connect the incorrect power supply to his/her electronics at home or
while traveling. Faults may also occur when using commercially available universal power
supplies that come with a variety of connectors. These devices allow the user to dial in the
voltage to levels as high as 24V, as well as switch polarity.