Abstract: A control device, such as a digital ballast controller, is adapted to be coupled to an electronic ballast, such as a DALI ballast, via a communication link, and is operable to determine whether the ballast is operating within the specifications of a predefined protocol standard, e.g., the DALI standard. For example, the control device may measure the bit times of a digital message received from the ballast and to determine if the bit times fall within the limits set by the standard. The control device may also determine the minimum delay time required between two digital messages received by the ballast and determine if the minimum delay time falls within the limit set by the standard. The control device may adapt its normal operation (e.g., how digital messages are received and transmitted) or may provide feedback (e.g., by flashing a lamp) in response to determining that the ballast is operating outside of the specifications of the standard.

Abstract: A two-wire switching circuit can handle a large inrush current, but does not require a neutral connection or a heavy-duty mechanical switch or relay. The switching circuit comprises a mechanical air-gap switch, a first controllably conductive device (e.g., a bidirectional semiconductor switch), and a second controllably conductive device (e.g., a latching relay), which are all adapted to be coupled between an AC power source and an electrical load when the air-gap switch is in a first position. First and second delay circuits control the semiconductor switch and the latching relay to be conductive at different times after the air-gap switch is changed to the first position. Specifically, the semiconductor switch is rendered conductive before the latching relay is rendered conductive, such that the semiconductor switch conducts the large inrush current. The latching relay conducts current from the AC power source to the electrical load after the inrush current has subsided.

Abstract: A two-wire switching circuit can handle a large inrush current, but does not require a neutral connection or a heavy-duty mechanical switch or relay. The switching circuit comprises a mechanical air-gap switch, a first controllably conductive device (e.g., a bidirectional semiconductor switch), and a second controllably conductive device (e.g., a latching relay), which are all adapted to be coupled between an AC power source and an electrical load when the air-gap switch is in a first position. First and second delay circuits control the semiconductor switch and the latching relay to be conductive at different times after the air-gap switch is changed to the first position. Specifically, the semiconductor switch is rendered conductive before the latching relay is rendered conductive, such that the semiconductor switch conducts the large inrush current. The latching relay conducts current from the AC power source to the electrical load after the inrush current has subsided.

Abstract: A control device, such as a digital ballast controller, is adapted to be coupled to an electronic ballast, such as a DALI ballast, via a communication link, and is operable to determine whether the ballast is operating within the specifications of a predefined protocol standard, e.g., the DALI standard. For example, the control device may measure the bit times of a digital message received from the ballast and to determine if the bit times fall within the limits set by the standard. The control device may also determine the minimum delay time required between two digital messages received by the ballast and determine if the minimum delay time falls within the limit set by the standard. The control device may adapt its normal operation (e.g., how digital messages are received and transmitted) or may provide feedback (e.g., by flashing a lamp) in response to determining that the ballast is operating outside of the specifications of the standard.