Line security system

摘要: A system for insuring the security of electrical transmission lines extending between a monitor station and remote utilizes voltage source at which impresses an AC signal on lines. At station, is rectified applied to current regulator provides quiescent pulsed direct constant level The arranged provide higher alarm when intruder detected station. monitoring shorted line fault detector reversal in direction normal flow occurs lines, open drop below detected, rise above detected. impressed periodically reduced amplitude barely sustains minimum test impedance.