https://www.circuitlab.com/
Though free but only a few tries for each session. Not much useful.

https://www.multisim.com/
This is good. So  far I have used for simulating small sections like filters, transistor amplifiers etc. The free version served the purpose.

https://www.falstad.com/mathphysics.html
Various Simulation tools are there. Yet to explore much.

Please note – The information provided here is on as is basis. I don’t guarantee their accuracy and proper functioning.