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 learning device with page indicators includes a case, a touch pad, an electronic control unit and multiple page indicators. When each learning card is placed on the touch pad, the position next to the page actuating mark of each learning card has one corresponding page indicator. When the page actuating mark is touched, the corresponding page indicator is activated.

Abstract: A main computer with multiple operating devices enables multiple users to manipulate the main computer.

Abstract: A system includes a host computer and operational devices. The operational devices are connected to the host computer by a connection device and utilizable by users. The host computer is used for executing an interactive program and a control manner specifying program. The control manner specifying program has a first routine for distributing the operational instructions of the interactive program to at least two users so that the interactive program is used by at least two users, and a second routine for changing the distribution method of the operational instructions of the interactive program to the users.

Abstract: An interactive learning software program includes a teaching computer, a plurality of operational devices and a notebook computer. The teaching computer is used for executing at least one interactive learning software program. The plurality of operational devices are used by the plurality of students and output an operational instruction to the teaching computer to use the interactive learning system. The notebook computer is used by the teacher, and the notebook computer is capable of executing an interactive control software program to output a control instruction to the teaching computer so that the interactive learning software selectively accepts the operating instruction from the operational device.

Abstract: An electronic switch is has a receiver for receiving external switch signal and to producing corresponding switch control signal. A decoder us provided to receive switch control signal from the receiver and to produce corresponding decoding signal containing a switch identification code. A memory stores at least one switch identification code, each switch PIN code corresponding to a respective switch element. A processor is provided to compare switch identification code from the decoder with switch PIN code in the memory and to turn on the corresponding switch element when the switch identification codes are matched. The processor has a learning mode for writing every received switch identification code from the decoder into the memory and corresponding every written switch PIN code to the at least one switch element respectively.