Everything for Electronics

# How To

#### Copper Cobweb Circuit Construction

Are you bored with conventional two-dimensional circuit layouts, or looking for a way to add an artistic flair to your next project? I’ve taken point-to-point construction style a step further by making it self-supporting, which opens up a wide range of physical circuit topologies. (Point-to-point construction usually uses supporting structures like terminal strips that are functional but not pleasing to the eye.) I call this construction style the copper cobweb. Here’s how to do it.

#### You Don’t Have to Be an Engineer to Design Your Own Electronic Circuits

Most of you have at one time or another thought about designing your own electronics. The thing stopping many of you is the fact that you realize you’re not a “real” graduate engineer. Well, so what? You don’t have to have an EE degree to design. You can do your own design with a little direction. Here’s my approach to it, so you can give it a try.

#### An Elegant Approach to Design a Variable Voltage Divider

A voltage divider is probably the most common electronic circuit. Despite its simplicity, it can be a design challenge for many folks, particularly beginners. This article presents a fast and accurate way to design a variable voltage divider with minimum math.

After reading the May-June 2018 NV article on Ohm’s law, I thought a follow-up article that goes a little deeper might be in order. Specifically, how Ohm’s Law together with a computer and a couple of tricks can be used to calculate the time dependence of much more complex circuits involving not just resistors but capacitors, inductors, op-amps ... you name it! In this article, I’ll describe a simple numerical method that is intuitive and solves many complex problems with just a few lines of code. No simulator needed!

#### An ESP8266 Live Wi-Fi Webcam

Having read about the ESP8266 NTP clock in previous issues of Nuts & Volts, an idea came to mind to construct an interface camera using the ESP8266. In this project, we used an old Android phone as a camera source and linked to an ESP8266 based webserver. The phone acts as a camera server and the ESP8266 web server acts as a client to the camera server. The webserver displays the live webcam on its web page.

#### TGI: The TEENSY Graphics Interface

The February and March 2018 editions of Nuts & Volts featured my article detailing the Arduino Graphics Interface (AGI) project which described a general-purpose hardware and software platform that could draw graphical objects onto the face of any analog oscilloscope. A reader challenged me to see if the AGI concept and software library could be ported to the newer and faster TEENSY 3.6 processor. This article describes the new and improved TEENSY Graphics Interface project that implements a fully operational “CRT Clock” as a working demonstration of a TEENSY based graphics platform.

#### Practical Ideas for Portable Magnetic Loop Antennas

Magnetic loop antennas are becoming popular today because they can be very efficient for their size, do not need radials (even though most designs are vertically polarized), have useful takeoff angles, and can be easily rotated to peak or null a signal. Here’s how I designed a convenient setup for myself.