Abstract: Described are devices for automatically adapting electrical polarity from a power source to a specified output polarity for use by an electrical load. In one implementation, power adaptation circuitry comprising one or more bridge circuits accept electrical power of unspecified polarity and output specified polarity. The bridge circuit may comprise a plurality of field-effect transistors (FETs) configured such that a particular subset of the FETs are energized to conduct electric current to the outputs when a particular polarity is applied at inputs.

Abstract: Described in this disclosure are battery contacts for use in electronic devices usable without soldering to a circuit board. The battery contact includes one or more contact features supported by leaf springs. The contact features touch a corresponding pad on the circuit board at time of assembly, providing an electrically conductive pathway. One or more of the battery contacts may include a spring-biased member configured to apply pressure to one or more batteries.