Initial condition inductor

In this section we will demonstrate the transient response of an inductor circuit with a switch that is normally closed. The initial condition of the inductor will not be specified by an IC= line in the circuit. Instead, the initial condition will be determined by PSpice from the initial state of the circuit before the switch changes position. If you wish to specify the initial condition of the inductor, it is specified in the same way as the initial condition of a capacitor. For an inductor, the direction for positive current is into the dotted terminal, as shown in Figure 6.1. The dot is always shown on the inductor graphic. The graphic should be rotated to obtain the desired direction of positive current flow. 

SDLUTlOn The initial condition of the inductor does not need to be specified because PSpice will determine the initial conditions from the circuit ... 

LUTI0I1 The initial condition of the inductor does not need to be specified because PSpice will determine the initial conditions from the circuit. Hi is a current-controlled voltage source. Its voltage is 2000 times the current through R2. To add a second plot in Probe, select Plot and then Add Plot to Window. 

Coupled reactions occur when the primary reaction results in an intermediate which enables the acceptor to react too. The main characteristic of this reaction is that the value of the induction factor is small, not exceeding 2 even under most favourable conditions for the induced change. Plotting F-, against the ratio of the initial concentrations of acceptor and inductor results in a curve having a limiting value. 

To protect the switch (and converter) from excess currents, a current limit is usually required. In this case, the current in the inductor, or in the switch, is sensed, and then compared against a set threshold. If and when that is momentarily exceeded, the control circuitry forces the switch to turn OFF immediately for the remainder of the switching cycle, so as to protect itself. In the next cycle, no memory is usually retained of what may have happened in the preceding cycle. Therefore, every switching cycle is started afresh, with the current being continuously monitored to ensure it is at a safe level. If not, protective action is again initiated, and can be repeated every cycle for several cycles if necessary, until the overcurrent condition ceases. 

---