Abstract: A conduction angle detection circuit, and systems and methods incorporating the same, is disclosed. The circuit includes a comparator having a first input and a second input, and configured to provide a pulse-width modulated output in response to comparison of signals at the first input with signals at the second input. The output has a pulse width representative of a dimmer setting of a dimmer circuit. The circuit also includes a limiting circuit coupled to the comparator and configured to receive a rectified voltage and to provide a voltage-limited output in response to the rectified voltage to the first input of the comparator. The circuit also includes a threshold supply circuit configured to provide a threshold voltage to the second input of the comparator, and a filter coupled to the comparator. The filter is configured to convert the pulse-width modulated output of the comparator to the dimmer reference level signal.

Abstract: A dimmer conduction angle detection circuit, and systems and methods incorporating the same, is disclosed. The circuit receives a gate drive signal from a PFC circuit and provides a dimmer reference level signal representative of a dimmer circuit's dimmer setting in response. The circuit includes a comparator with first and second inputs that provides a pulse-width modulated output in response to comparing signals received at the inputs. The pulse-width modulated output has a pulse width representative of the dimmer circuit's dimmer setting. The circuit also includes an input network, coupled to the comparator, to receive the gate drive signal and to provide an output, in response, to the comparator's first input. The circuit also includes a threshold supply circuit to provide a threshold voltage to the comparator's second input, and a filter, coupled to the comparator, to convert the comparator's pulse-width modulated output to the dimmer reference level signal.

Abstract: A current sense rectifier circuit comprises an assembly input terminal for receiving a current input signal having an alternating current (AC) waveform. A negative half-wave circuit generates a first input signal representative of negative portions of the current input signal. A positive half-wave circuit generates a second input signal representative of positive portions of the current input signal. The negative and positive half-wave circuits each include a single diode and a resistance. A closed-loop amplifier has an inverting input terminal connected to the negative half-wave circuit, and a non-inverting input terminal connected to the positive half-wave circuit. The closed-loop amplifier inverts the first input signal and provides a DC voltage output signal via an output terminal that is a function of the inverted first input signal and the second input signal. An assembly output terminal is connected to the output terminal to receive the DC voltage output signal therefrom.

Abstract: A ballast to power a lamp includes two switches, each to selectively connect the ballast to respective high voltage terminals, each having two states (ON and OFF). The ballast also includes a converter circuit that provides a voltage to energize the lamp, and a detector circuit. The detector circuit includes two inputs, each coupled to a respective switch; two resistors, each coupled to a respective input; two outputs, each connected to the converter circuit; a transistor network; and a capacitor. One output provides the converter circuit with power, and is connected to the input via the resistors. The other provides the converter circuit with a control signal, indicating a voltage level so as to power the lamp to a particular light level, depending on the switches' states. The transistor network detects a differential voltage between the inputs, generating the control signal as a result. The capacitor smoothes the control signal.

Abstract: A switch status detection circuit is provided, including three input terminals and a ground terminal. Two input terminals connect to a power supply via respective switches, receiving a respective voltage signal. The third connects to the power supply, receiving a neutral signal. A neutral synchronization circuit, between the third and the ground terminal, generates a positive pulsed current signal as a function of the neutral signal. Two capacitors, each with a respective first terminal connected to a corresponding input terminal, and a respective second terminal connected to the ground terminal, are charged by the current signal when the capacitor's corresponding switch is in an off state. Respective output terminals are coupled to each capacitor's first terminal to provide respective control signals, indicating the respective switch's state as a function of a voltage level across that capacitor. Each control signal has a logic level corresponding to its respective switch's state.

Abstract: A ballast to power a lamp includes two switches, each to selectively connect the ballast to respective high voltage terminals, each having two states (ON and OFF). The ballast also includes a converter circuit that provides a voltage to energize the lamp, and a detector circuit. The detector circuit includes two inputs, each coupled to a respective switch; two resistors, each coupled to a respective input; two outputs, each connected to the converter circuit; a transistor network; and a capacitor. One output provides the converter circuit with power, and is connected to the input via the resistors. The other provides the converter circuit with a control signal, indicating a voltage level so as to power the lamp to a particular light level, depending on the switches' states. The transistor network detects a differential voltage between the inputs, generating the control signal as a result. The capacitor smoothes the control signal.

Abstract: A current sense rectifier circuit comprises an assembly input terminal for receiving a current input signal having an alternating current (AC) waveform. A negative half-wave circuit generates a first input signal representative of negative portions of the current input signal. A positive half-wave circuit generates a second input signal representative of positive portions of the current input signal. The negative and positive half-wave circuits each include a single diode and a resistance. A closed-loop amplifier has an inverting input terminal connected to the negative half-wave circuit, and a non-inverting input terminal connected to the positive half-wave circuit. The closed-loop amplifier inverts the first input signal and provides a DC voltage output signal via an output terminal that is a function of the inverted first input signal and the second input signal. An assembly output terminal is connected to the output terminal to receive the DC voltage output signal therefrom.

Abstract: A dimmer conduction angle detection circuit, and systems and methods incorporating the same, is disclosed. The circuit receives a gate drive signal from a PFC circuit and provides a dimmer reference level signal representative of a dimmer circuit's dimmer setting in response. The circuit includes a comparator with first and second inputs that provides a pulse-width modulated output in response to comparing signals received at the inputs. The pulse-width modulated output has a pulse width representative of the dimmer circuit's dimmer setting. The circuit also includes an input network, coupled to the comparator, to receive the gate drive signal and to provide an output, in response, to the comparator's first input. The circuit also includes a threshold supply circuit to provide a threshold voltage to the comparator's second input, and a filter, coupled to the comparator, to convert the comparator's pulse-width modulated output to the dimmer reference level signal.

Abstract: A conduction angle detection circuit, and systems and methods incorporating the same, is disclosed. The circuit includes a comparator having a first input and a second input, and configured to provide a pulse-width modulated output in response to comparison of signals at the first input with signals at the second input. The output has a pulse width representative of a dimmer setting of a dimmer circuit. The circuit also includes a limiting circuit coupled to the comparator and configured to receive a rectified voltage and to provide a voltage-limited output in response to the rectified voltage to the first input of the comparator. The circuit also includes a threshold supply circuit configured to provide a threshold voltage to the second input of the comparator, and a filter coupled to the comparator. The filter is configured to convert the pulse-width modulated output of the comparator to the dimmer reference level signal.