LTSpice

LTSpice is a popular simulation package.

Tips/Techniques

Amp Hour

https://theamphour.com/196-an-interview-with-mike-engelhardt-spice-simulator-synteresis/

Simulating a timer

https://www.youtube.com/watch?v=-aQ77YI7inI I think (without double checking) that this is similar to the beginner Make Electronics: Learning by Discovery book by Charles Platt (the 2nd edition is the one I've read and own, but the 3rd is available). Preview here: http://web.archive.org/web/20201128100847/https://cdn.makezine.com/make/shed/make_electronics_1.pdf In that book you use a PUT, Programmable Unijunction Transistor (unusual variant) in order to make an alarm buzz (maybe one 2nd thought, this isn't exactly as the video, which I've yet to watch...). https://www.circuitstoday.com/programmable-ujt