PROTECTOR FOR ORGANISM INTRUDING TO INTAKE PATH

摘要

PURPOSE:To prevent electric shock to large-size organisms by a method in which a pair of metal plates are provided on the upstream and downstream sides of an electric screen to make up a bridge circuit including an electric resistance formed by the paired metal plates, and the control power source of the electric screen is controlled by output signals from the bridge circuit not equilibrated. CONSTITUTION:Paired metal plates 6 consisting of metal plates 5 are provided on the upstream and downstream sides of an electric screen 3 in an intake channel 1 to make up a bridge circuit 7 including electric resistances Ra and Rb which are formed by the plates 6. Under a condition that large-size organisms do not intrude into the channel 1, a movable terminal K is regulated to equilibrate the circuit 7. When large-size organism intrudes into any one of the plates 6, one of the resistances Ra and Rb is changed to put the equilibrium of the bridge 7 to out of order, and an electric current flows between output terminals (a) and (b). The electric current is converted into voltage in a converter H and amplified, and the control power source of the screen 3 is turned OFF for a fixed time period through a timer circuit T by a control circuit C.