The invention relates to a miniature dual-power supply automatic conversion switch. The miniature dual-power supply automatic conversion switch comprises an automatic conversion device, a normally-used
circuit breaker and a back-up
circuit breaker, wherein the automatic conversion device comprises a shell,
intelligent control circuit boards, mechanism racks, a motor, a
bevel gear and two groups of transmission assemblies, each group of transmission
assembly comprises a transmission gear, a
cam and a conversion arm, the transmission gear is linked with the
bevel gear, the
cam is linked with the transmission gear, the conversion arm is rotatably arranged on the mechanism rack, corresponding to the
cam and used for driving a
handle of the normally-used
circuit breaker / a
handle of the back-up circuit breaker, the cam rotates with the transmission gear so as to drive the conversion arm to rotate, a breaking piece is movably arranged on the mechanism racks and is corresponding to a part between the transmission gear and the cam, the transmission gear and the breaking piece are freely matched in a closing direction and are matched in a linkage way in a breaking direction, an
interlocking mechanism is arranged in the shell and is matched with the conversion arm in a linkage way, and the
intelligent control circuit boards are used for controlling the motor to positively rotate, reversely rotate and stop. The miniature dual-power supply automatic conversion switch has the advantages of compact structure, high reliability, safety, reliability and small size and is convenient to install.