Devices that couple to high voltage transmission lines obtain power
themselves using the body capacitance of an element of the devices. The
devices generate a comparatively lower voltage from the current flowing
between the high voltage line and the element of the device that
generates the body capacitance. The devices can be used to operate
sensors that monitor the transmission lines or parameters of the power
distribution system, such as current, line temperature, vibration, and
the like. The devices can also be used as indicators, such as aircraft
warning lights, information signs, etc. In addition, the devices can
operate as RF transmission/reception or repeater devices, radar devices,
mesh networking nodes, video/audio surveillance, sound emitting devices
for scaring animals, drones that traverse the power line, etc. Because
the devices operate in response to line voltage rather than current, the
devices are reliable even in low current conditions.