Needing help with RL transients

Discussion in 'Homework Help' started by dbeckett91, Apr 6, 2011.

  1. dbeckett91

    Thread Starter New Member

    Apr 6, 2011
    I am looking for help with a question I have regarding working out the current in a circuit I have been given, the problem comes where my tutor will not be around for a while so I am stuck for which equations to use but here is the question below with the circuit diagram.

    Work out the current through R4 and through R5&L3...
    - As soon as the switch is closed
    - After the switch has been closed for a long time (5time constant)
    - As soon as the switch is opened
    - 400nS after the switch is opened


    I have worked out my time constants to be 6.833uS (charging) and 872.340nS (discharging). I also think I may have worked out the current when the switch is first closed to be 7.31mA for R4 and 0A for R5&L3.
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    Your values so far look fine.