As with many inventions, two people had the idea for an integrated circuit at almost the same time. Transistors had become commonplace in everything from radios to phones to computers, and now ...

[Kevin Darrah] wanted to make a simple 3.3V regulator without using an integrated circuit. He wound up using two common NPN transistors and 4 1K resistors. The circuit isn’t going to beat out a ...

The board monitors the voltage drop across a resistor in the doorbell circuit ... made out of a comparator and a resistor (more about that in a second), and four transistors for triggering ...