Cable Capacitance...

Discussion in 'General Electronics Chat' started by odgerel, Jan 29, 2008.

  1. odgerel

    Thread Starter New Member

    Jan 29, 2008
    2
    0
    Hi, All.
    I would like to know about following. If you know please help me!!!

    Question:
    500m common communication cable (TPP 10x2x0.5) is connected directly to the amplifier filter etc (charge amp) without any external power supply. If there is some external forces about 6-20Kg on the cable, amp senses that intrusion occurs on the cable. But I dont understand how to sense cable signal. I think, op-amp senses the difference of the cable capacitance. But there is no any power supply in cable. Is it right?
     
  2. rwmoekoe

    Active Member

    Mar 1, 2007
    172
    0
    i think what you thought is right. it's measuring the cable capacitance.
    i think it can be done by for instance passing a low frequency signal to one lead and measuring the crosstalk signal at the other. any significance changes in the amplitude of the crosstalk signal would mean a change in the capacitance, hence the cables proximity
     
  3. odgerel

    Thread Starter New Member

    Jan 29, 2008
    2
    0
    Thanks for your advice. Also one question. Help me.
    Can I measure and amplify the electrostatic charge of cable when cable is deformed due to the exterior forces? I mean if there is some deformations on the cable, copper wires of cable are rubbed each other then there is generated the electrostatic charge.
     
  4. rwmoekoe

    Active Member

    Mar 1, 2007
    172
    0
    wow, you think that far.
    it's a great idea i guess.
    it's only that i think the odds are too hard to predict, hence somewhat useless.
    electrostatics are dependent on many circumstances don't you think so?
    :( i don't know exactly how to measure it accurately. maybe someone in the forum can give a helping hand?
     
Loading...