A signal processing circuit includes a buffer, a first capacitor, a second capacitor, a first switch and a second switch. The buffer includes an input terminal for receiving an external signal and an output terminal for outputting an output signal. The first switch is coupled between the output terminal of the buffer and the first capacitor. The second switch is coupled between the output terminal of the buffer and the second capacitor. The first switch and the second switch are turned on alternately.

A signal processing circuit includes a buffer, a first capacitor, a second capacitor, a first switch and a second switch. The buffer includes an input terminal for receiving an external signal and an output terminal for outputting an output signal. The first switch is coupled between the output terminal of the buffer and the first capacitor. The second switch is coupled between the output terminal of the buffer and the second capacitor. The first switch and the second switch are turned on alternately.

A circuit includes a high-side switch and a low-side switch. A first inverter includes first and second discharge current paths activatable to sink first and second discharge currents, respectively, from the control terminal of the high-side switch. A second inverter includes first and second charge current paths activatable to source first and second charge currents to the control terminal of the low-side switch. A high-side sensing current path includes an intermediate high-side control node, and a low-side sensing current path includes an intermediate low-side control node. The second discharge current path is selectively enablable in response to a high-side detection signal at the intermediate high-side control node having a high logic value, and the second charge current path is selectively enablable in response to a low-side detection signal at the intermediate low-side control node having a low logic value.

A circuit includes a high-side switch and a low-side switch. A first inverter includes first and second discharge current paths activatable to sink first and second discharge currents, respectively, from the control terminal of the high-side switch. A second inverter includes first and second charge current paths activatable to source first and second charge currents to the control terminal of the low-side switch. A high-side sensing current path includes an intermediate high-side control node, and a low-side sensing current path includes an intermediate low-side control node. The second discharge current path is selectively enablable in response to a high-side detection signal at the intermediate high-side control node having a high logic value, and the second charge current path is selectively enablable in response to a low-side detection signal at the intermediate low-side control node having a low logic value.

A microcontroller based multifunctional electronic switch using a detection circuit design to convert external control signal into message carrying sensing signal readable to the microcontroller. Based on a time length of sensing signal and a format of the sensing signal received in a preset instant period of time the microcontroller through the operation of its software program codes is able to recognize working modes chosen by the external control signal generated by user, and thereby selecting appropriate loops of subroutine for execution. The system and method of the present invention may simultaneously be applicable to detection circuit design using infrared ray sensor, electrostatic induction sensor, conduction based touch sensor or push button sensor for performing multifunctions such as controlling on/off switch performance, diming or speed control and delay timer management within the capacity of a single lighting load or an electrical appliance.

A microcontroller based multifunctional electronic switch using a detection circuit design to convert external control signal into message carrying sensing signal readable to the microcontroller. Based on a time length of sensing signal and a format of the sensing signal received in a preset instant period of time the microcontroller through the operation of its software program codes is able to recognize working modes chosen by the external control signal generated by user, and thereby selecting appropriate loops of subroutine for execution. The system and method of the present invention may simultaneously be applicable to detection circuit design using infrared ray sensor, electrostatic induction sensor, conduction based touch sensor or push button sensor for performing multifunctions such as controlling on/off switch performance, diming or speed control and delay timer management within the capacity of a single lighting load or an electrical appliance.

An output circuit includes a comparator circuit, a voltage conversion circuit and a signal output circuit. The comparator circuit detects an operating mode based on a first supply voltage and a second supply voltage and generates a first control signal. The voltage conversion circuit adjusts a level of an output voltage from a low-dropout regulator according to the first control signal to generate a first voltage, and generates a second voltage according to the first control signal and the first voltage. The signal output circuit adjusts a level of a digital signal according to the first voltage, the second voltage and the first supply voltage to generate a digital output signal corresponding to the operating mode.

An output circuit includes a comparator circuit, a voltage conversion circuit and a signal output circuit. The comparator circuit detects an operating mode based on a first supply voltage and a second supply voltage and generates a first control signal. The voltage conversion circuit adjusts a level of an output voltage from a low-dropout regulator according to the first control signal to generate a first voltage, and generates a second voltage according to the first control signal and the first voltage. The signal output circuit adjusts a level of a digital signal according to the first voltage, the second voltage and the first supply voltage to generate a digital output signal corresponding to the operating mode.

A smart switch apparatus is coupled between a live wire of an indoor power and two output terminals of a SPDT (Single Pole Double Throw) switch. Two ends of a load are respectively connected to a neutral wire of the indoor power and an input terminal of the SPDT switch. The smart switch apparatus includes an on-off status detector, a switch position detector, a controller, an on-off controller and a power circuit. The on-off status detector is coupled to the live wire of the indoor power for generating an on-off status signal. The switch position detector is coupled to the two output terminals of the SPDT switch for generating a switch position signal. The controller is coupled to the on-off status detector and the switch position detector for receiving the on-off status signal and the switch position signal. The on-off controller is coupled to the two output terminals of the SPDT switch and the live wire of the indoor power to selectively turn on or turn off the target power loop according to the on-off control signal.

A smart switch apparatus is coupled between a live wire of an indoor power and two output terminals of a SPDT (Single Pole Double Throw) switch. Two ends of a load are respectively connected to a neutral wire of the indoor power and an input terminal of the SPDT switch. The smart switch apparatus includes an on-off status detector, a switch position detector, a controller, an on-off controller and a power circuit. The on-off status detector is coupled to the live wire of the indoor power for generating an on-off status signal. The switch position detector is coupled to the two output terminals of the SPDT switch for generating a switch position signal. The controller is coupled to the on-off status detector and the switch position detector for receiving the on-off status signal and the switch position signal. The on-off controller is coupled to the two output terminals of the SPDT switch and the live wire of the indoor power to selectively turn on or turn off the target power loop according to the on-off control signal.