LIGHT SOURCE UNIT AND LIGHTING FIXTURE

摘要

The light source unit includes a light source circuit including N (N≧3) pairs of a light source group including one or more solid light emitting elements and a constant current circuit connected in series with the light source group to keep, constant, current flowing through the light source group, a full-wave rectification circuit for performing full-wave rectification on AC voltage, and a control circuit. The first pair is connected to the full-wave rectification circuit. The k-th (2≦k≦N) pair is connected in parallel with the constant current circuit of the (k−1)-th pair so that the light source groups of the k-th and (k−1)-th pairs are in series. The control circuit terminates operations of the constant current circuits of the N pairs or limits currents flowing through the light source groups of the N pairs in response to detection of light or a signal.

主权项

1. A light source unit, comprising:
a light source circuit including N pairs of a light source group including one or more solid light emitting elements and a constant current circuit connected in series with the light source group to keep, constant, current flowing through the light source group, where N is an integer equal to or greater than 3; a full-wave rectification circuit which includes a first output end and a second output end and is configured to perform full-wave rectification on AC voltage to cause DC voltage between the first output end and the second output end; and a control circuit including a detector configured to detect light or signal from an external source, a first pair of the N pairs being connected between the first output end and the second output end of the full-wave rectification circuit, a k-th pair of the N pairs being connected in parallel with the constant current circuit of a (k−1)-th pair of the N pairs so that the light source group of the k-th pair and the light source group of the (k−1)-th pair are in series, where k is an integer equal to or greater than 2 and equal to or smaller than N, and the control circuit being configured to, when the detector detects the light or signal, terminate operations of constant current circuits of the N pairs or limit current flowing through light source groups of the N pairs.