((nothing to do)) . . . well -- i tested some Sine amplitude detector concepts in Spice a longer while ago - but i didn't yet found these . . .
so a quick peak detector --
-- you can find better circuits from web , but it is actually good this one isn't -- coz it shows how reaction speed and error change along the input . . .
. . . so -- it likely means less trouble if you scale down your input and shift it to required range . . .
__________
Experimental ::

________________________
d/s Mod.1 ::
___________________
(d/s Mod.2) Updated and simplified - compared to Experimental v. ::

 

@petewh If you place your cursor over the schematic and right click to get a drop down menu you can select "Open Link In New Window" or tab using firefox, not sure about other browsers, but try opening it in a separate window -that's what I have to so in order to see the whole schematic clearly.