\documentclass[11pt]{article} %Gummi|065|=) \usepackage{graphicx} \usepackage{caption} \usepackage{xcolor} \usepackage[vcentering,dvips]{geometry} \geometry{papersize={6in,9in},total={4.5in,6.8in}} \title{\textbf{Door Alarm}} \author{Steak Electronics} \date{} \begin{document} \maketitle \tableofcontents \textcolor{green!60!blue!70}{ \section{Overview}} Client wants a door alarm. Let's do a few transistors, an audio amplifier board, a magnet and magnetic reed switch, along with a light switch. Functionality req'd: \\ \\ Makes noise when door opened. \\ \\ Able to be shut off with light switch. \textcolor{green!60!blue!70}{ \section{BOM}} Any audio amplifier loud enough will work. I'm going to use this one: \\ \\ IS31AP4088A-QFLS2-EB \\ \\ I think I have speakers and transistors. I'll need a magnetic reed switch and magnet. They should be black, as the door is black. \\ \\ MS-324-3-3-0500 \\ \\ let's also try 59140-1-S-03-A,\footnote{A and F ending letters on this, A is tinned, F untinned leads} as first co. doesn't make the matched magnets... \\ \\ and the magnet, 57140-000 A speaker, although I have plenty in my junk bin. AS07708PS-2-WR-R \\ \\ That's a start. \section{Work Log: LM324, LM555, TIP120,125} I spent a bit on this during the evening. I tried first with a LM324, in falstad (sim software) to see if I could make a function gen, out of 3 op amps. I was unable to get the sim to work, although reportedly the circuit works online (ref: https://www.eevblog.com/forum/beginners/simple-analog-function-generator-design/msg1174548/\#msg1174548) I decided instead, to simulate a triple 5 with a LM324, to finally a transistor output, and this worked in sim. I breadboarded the circuit however, the output was not switching correctly. It turned out later, that I had not read my TIP125 close enough - that was the PNP Q. Before realizing this error, I breadboarded two op amps, (ref: https://electronics.stackexchange.com/questions/311648/obtaining-a-triangle-wave-from-a-square-wave-using-a-lm324n-op-amp) and these were able to make the square / triangle wave without issue. \end{document}