Voltage controlled stwich in LTSpice

[Sukhdeep]

Hi all,

I am facing problem With implementation of voltage controlled switch in LT Spice.
I Wonder if the threshold voltage of switch should be greater than the pulse voltage Applied to switch or rather it should be less than the pulse voltage!!!
if i apply pulse voltage smaller than the threshold voltage of switch then it Works otherwise it doesnt work!! Is it meant to be so?

Thanks

 

[Harald Kapp]

if i apply pulse voltage smaller than the threshold voltage of switch then it Works

This doesn't make sense. You probably have another error in your circuit.

The threshold voltage is set ideally midway between min and max of the controlling voltage. Example: Pulse voltage varies from 0V (off) to 1V (on). Set the threshold to 0.5V. For extra clean switching add a small hysteresis, e.g. 0.05V to the switch parameters.

Upload the .asc file (only the relevant portion around the switch and the controlling pulse voltage is required) so we can check it.

 

[Sukhdeep]

here is image of the .asc Circuit that doesnt work if Vt of switch is lower thab Pulse voltage..

Can you please see the mistake?

I dont know if its possible to attach .asc file here?

 

[Sukhdeep]

Hi,

Did you found mistake? If yes kindly let me know too.

 

[Harald Kapp]

The image is not very helpful. I don't see an obvious mistake but I don't have time to redraw it in LTSPICE for simulation. See attached simulation file for a demo of a switch.