Re: problem with proteus
Heres a simple one.
The circuit has been tweaked a little in order to make the lamp ligthing quite smooth.
First I've increased "Frame per second" to 50 as this helps to make less flickering the lamp, though it requires more CPU resources.
Then I changed some spice parameters to make simulation less accurate but faster; ABSTOL=1e-08 and VNTOL=1e-3 (quite acceptable considering the voltage values of the circuit), RELTOL=1e-2, PIVREL=1e-2 (help to make admittances matrix well conditioned) and TRTOL=50 (approaches to a fixed timestep rather than variable one). All applied via the system menu - set animation options - spice options.
Iain.