Abstract: A Totem Pole PFC circuit includes at least one fast-switching leg, a slow-switching leg, and a control unit. Each fast-switching leg includes a fast-switching upper switch and a fast-switching lower switch. The slow-switching leg is coupled in parallel to the at least one fast-switching leg, and the slow-switching leg includes a slow-switching upper switch and a slow-switching lower switch. The control unit receives an AC voltage with a phase angle, and the control unit includes a current detection loop, a voltage detection loop, and a control loop. The control loop generates a second control signal assembly to respectively control the slow-switching upper switch and the slow-switching lower switch. The control loop controls the second control signal assembly to follow the phase angle, and dynamically adjusts a duty cycle of the second control signal assembly to turn on or turn off the slow-switching upper switch and the slow-switching lower switch.

Abstract: A multi-axis dome camera includes a base having a support bracket fixedly mounted thereon and a pivoted bracket pivotally connected to an upper end of the support bracket to be 180-degree vertically turnable relative to the latter; a rotating disc being connected to a top of the pivoted bracket to produce a right angle, so that the rotating disc is able to conduct directly on the pivoted bracket the adjustment of an angle by which a captured image is presented; and a camera lens mounted on the rotating disc to rotate along with the rotating disc. With the above arrangements, the camera lens may change in its vertical and horizontal positions to capture images presented in more different directions. The multi-axis dome camera requires fewer parts to enable reduced manufacturing cost and is therefore suitable for mass production.