An example apparatus includes power amplification circuitry and current-level switch circuitry. The power amplification circuitry has a first input port, a second input port, and field-effect transistor (FET) circuitry, the FET circuitry to operate in a saturation mode while drawing power provided at the first input port from a first power source. The current-level switch circuitry is to sense a change in a current-level used to maintain the FET circuitry in the saturation mode and, in response to the sensed change in the current-level, to cause the power amplification circuitry to draw power provided at the second input port from a second power source while maintaining the saturation mode of the FET circuitry.

A constant voltage generator circuit is provided with an operational amplifier including a feedback circuit having a first resistor, and an output transistor. The operational amplifier generates a feedback voltage generated by dividing an output voltage between an output terminal and a substrate voltage potential of the constant voltage generator circuit by the first resistor and a second resistor. Then, the operational amplifier is configured to amplify a voltage potential difference between a predetermined reference voltage and the feedback voltage and to output a control voltage. The output transistor controls an output voltage based on the control voltage from the operational amplifier, and the feedback circuit is further configured to superimpose high-frequency noise components from the substrate voltage potential onto the feedback voltage.

A constant voltage generator circuit is provided with an operational amplifier including a feedback circuit having a first resistor, and an output transistor. The operational amplifier generates a feedback voltage generated by dividing an output voltage between an output terminal and a substrate voltage potential of the constant voltage generator circuit by the first resistor and a second resistor. Then, the operational amplifier is configured to amplify a voltage potential difference between a predetermined reference voltage and the feedback voltage and to output a control voltage. The output transistor controls an output voltage based on the control voltage from the operational amplifier, and the feedback circuit is further configured to superimpose high-frequency noise components from the substrate voltage potential onto the feedback voltage.

The present invention discloses a bias current generation circuit. An operation amplifier compares an input voltage having a zero-temperature coefficient and a feedback voltage to generate a driving voltage. An output transistor generates a bias current according to the driving voltage. A variable resistive circuit is electrically coupled to the output transistor through a feedback node to generate the feedback voltage according to the bias current and includes series-coupled resistors and switch transistors. Each of the resistors has a resistance having a positive temperature coefficient and includes a current input terminal and a current output terminal. Each of the switch transistors is electrically coupled between the current output terminal of one of the resistors and a ground terminal. One of the switch transistors turns on according to a control voltage variable according to the temperature variation to enable resistors to generate the resistance having a negative temperature coefficient.

The present invention discloses a bias current generation circuit. An operation amplifier compares an input voltage having a zero-temperature coefficient and a feedback voltage to generate a driving voltage. An output transistor generates a bias current according to the driving voltage. A variable resistive circuit is electrically coupled to the output transistor through a feedback node to generate the feedback voltage according to the bias current and includes series-coupled resistors and switch transistors. Each of the resistors has a resistance having a positive temperature coefficient and includes a current input terminal and a current output terminal. Each of the switch transistors is electrically coupled between the current output terminal of one of the resistors and a ground terminal. One of the switch transistors turns on according to a control voltage variable according to the temperature variation to enable resistors to generate the resistance having a negative temperature coefficient.

Disclosed is a semiconductor integrated circuit for a regulator, including: a voltage control transistor connected between a voltage input terminal to which a DC voltage is input and an output terminal; a control circuit that controls the voltage control transistor according to a feedback voltage of an output; a first transistor which is provided in parallel with the voltage control transistor and to which an electric current in a proportional reduction from an electric current flowing to the voltage control transistor flows; a first comparison circuit that determines which of the electric current flowing to the first transistor and a predetermined current value is larger; and a first output terminal for outputting the determination result. An output of the first comparison circuit is inverted in response to the flowing to the first transistor of the electric current smaller than a preset rotation lock detection current value.

Disclosed is a semiconductor integrated circuit for a regulator, including: a voltage control transistor connected between a voltage input terminal to which a DC voltage is input and an output terminal; a control circuit that controls the voltage control transistor according to a feedback voltage of an output; a first transistor which is provided in parallel with the voltage control transistor and to which an electric current in a proportional reduction from an electric current flowing to the voltage control transistor flows; a first comparison circuit that determines which of the electric current flowing to the first transistor and a predetermined current value is larger; and a first output terminal for outputting the determination result. An output of the first comparison circuit is inverted in response to the flowing to the first transistor of the electric current smaller than a preset rotation lock detection current value.

An irrigation system comprises an irrigation controller that receives user input and provides a power signal and command and message data to an encoder. The encoder encodes the command and message data onto the power signal to provide a data encoded power waveform that is sent over a two-wire path. The irrigation system further comprises one or more decoders in communication with the two-wire path to receive the data encoded power waveform and one or more irrigation valves in communication with the one or more decoders. The data encoded power waveform provides power to the decoders and the decoders decode the command and message data from the data encoded power waveform to control the irrigation valves according to the user input.

An irrigation system comprises an irrigation controller that receives user input and provides a power signal and command and message data to an encoder. The encoder encodes the command and message data onto the power signal to provide a data encoded power waveform that is sent over a two-wire path. The irrigation system further comprises one or more decoders in communication with the two-wire path to receive the data encoded power waveform and one or more irrigation valves in communication with the one or more decoders. The data encoded power waveform provides power to the decoders and the decoders decode the command and message data from the data encoded power waveform to control the irrigation valves according to the user input.

An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every 1/2 cycle of the alternating-current voltage.