Design Method of Passive Attenuator for Prevention of Electric Shock in a Large Crane Near Radio Broadcasting Antenna

Abstract

When a large crane is used near a medium wave radio broadcasting antenna, it operates as an effective receiving antenna and a voltage induced at a crane hook which gives a worker an electric shock.
In a practical experiment, we successfully developed an attenuator which employs a passive electric circuit to install those cranes, and announced the experiment results.
In this time, we theoretically analyzed this attenuator which employs a passive electric circuit and show the design method of a passive attenuator from the results of analysis. In this paper, first the equivalent circuit of the crane equipped with the passive attenuator as a receiving antenna is induced. We show that the attenuated characteristics of a passive attenuator by the model experiment accords with the theoretical attenuated characteristics which employ an equivalent circuit under the same condition.