Switch components

The following are the circuit components supported as of SimLab:

Component Icon Description
Switch square/formula Control components, orientation affects the computation.

Introduction

The switch component is a semiconductor component available for transient solutions. It deals with turning the component states (on or off) depending on a specific set of commands.

In the switch square user defines the pulse characteristics according to which the switch is controlled. While in case of the switch formula user can define a formula and if this formula is greater than zero the on state will be activated.

Square switch

Below is the definition of the square switch:



On state resistance: resistance when pulse it at maximum

Off state resistance: resistance when pulse it at minimum

Note: zero or negative values of off state resistance are not allowed

Pulse beginning time: beginning of pulse signal

Pulse end time: The total time of the pulse signal



Square switch Example

For the following circuit with a sinusoidal voltage source connected to a simple coil conductor components, a square switch is defined with the following pulse characteristics.



Then the voltage of the source and the coil conductors is shown in the below image.



As it can be seen the voltage at the coils for the time between t = 1s and t = 5s is negligible because the switch is turned ON during this time.

Formula switch

The dialog box of switch formula is as below:



On state resistance: resistance when pulse it at maximum

Off state resistance: resistance when pulse it at minimum

Switch command formula: here user can specify a formula for control of the on and off state. If the given formula evaluates to greater than zero then switch is turned on.

Note: To be able to use this Formula switch it needs to use an internal function existing and interpreting in Flux, the VALID function. The Valid function allows creating square wave signals.

The Valid(x,x1,x2) function returns:

  • 1 if x is in [X1 , X2[
  • 0, otherwise

Formula switch Example

In case of transient application it is also possible to define a rectangular pulse function described in the figure like:

Valid(TIME, T1 , T2 )

where:

  • TIME is the parameter time
  • T1 is the instant of the pulse start = [0, T1] the switch is OFF
  • T2 is the instant of the pulse end = [T1, T2] the switch is ON

Note: In case of a motor the time can be replaced by an angle (the angular position of the motion). This angle can be the parameter used in the valid function for the command of the switch