Abstract: A circuit tester indicates the presence of power at an outlet and the continuity of a resistive load connected to the outlet. The tester is particularly useful as an automotive block heater circuit tester. The tester has a housing with a male end equipped with the prongs conventionally found on a male electrical plug and a female end with a socket of the same configuration as a conventional female electrical outlet. One of the sockets is divided into inner and outer terminals that are sequentially engaged by the mating prong of a male plug as it is inserted into the female end of the tester. A lamp and a resistive circuit are connected into this structure in such a way that when the tester is plugged into a live outlet, the lamp is illuminated brightly. When a male plug is inserted into the female end of the tester, the lamp initially dims to confirm continuity of the load and then brightens as the male plug is fully seated in the socket.

Abstract: In one embodiment, a battery case and lamp assembly detachably engage with a pair of clips secured to the front of the helmet. In the preferred embodiment a lower horizontal rod attached to the back of the battery case clips into a pair of clips secured to the front of the helmet and a pair of resilient claws at the top of the battery casing, detachably engage any one of a plurality of projecting teeth, also secured to the front of the helmet. The case and lamp assembly pivot around the horizontal rod so that the angle of the lamp assembly can be adjusted to suit the user. Switch means are provided for the lamp assembly to connect and disconnect same from the batteries within the battery case.