Abstract: A continuity tester for a lamp, coaxial, plug connector has a receptacle connector with first and second coaxial, annular receptacle contacts at a same axial spacing apart as power and ground contacts of the lamp connector for electrical engagement when plugged therein and, a probe contact engageable with only the power contact. First and second LEDs connect to a battery via first and second parallel circuits. A biasing resistor in the second circuit ensures that battery power is provided to only the first LED when a battery circuit is completed only by electrical engagement of the first contact and the probe contact with the power contact of the male coaxial connector to signal absence of a short circuit and to only the second LED when a circuit is completed also by engagement of the second tester contact with the ground contact of the lamp connector to signal a short circuit.

Abstract: A modular downlight assembly having a channel shaped back housing for mounting in a ceiling cavity and formed with a series of identical apertures receiving, respectively, when mounted in the cavity, selected similar individual downlight modules. Each module has a mounting plate with a power supply mounted on an upper back face received, concealed from view, in an aperture and a lamp housing pivotally suspended from a turnable on a lower face by a scissor linkage for extension and retraction out of and into the housing channel. A protractor for indicating rotational direction is marked on the lower face of the mounting plate. Meshed gear teeth are provided on endmost links of the two linkages of each scissor link, synchronizing their movement. Selected links have movement limiting flanges extending into paths of movement of adjacent links and of the lamp housing limiting extension, pivotal movement and rotation.

Abstract: An aiming device for track lighting includes an elbow member rotatively mounting a lamp housing to a vertical extension tube. The elbow member has an upper end connected to a lower end of the extension tube for rotation in a horizontal plane through 355 and a lower, transverse end formed with an annulus of locking teeth and an internal rotation limiting rib. The lamp housing has a lateral mounting plate with a connecting turret with a rim of locking teeth, a hub formed with a screw socket and a pair of radially extending rotation preventing members enclosing between them a lead receiving aperture within the turret. A clamping screw can be manually adjusted between a locking position clamping the mounting plate immovably to the elbow by locking engagement of respective teeth and a release position permitting vertical rotation of the lamp housing limited by engagement of the rotation limiting rib and rotation preventing members.