Everything for Electronics

# Theory

#### Transmission Lines and SWR

Any conductor carrying an AC current can be treated as a transmission line. Here, we'll talk about a basic element of transmission lines: the standing wave ratio. Find out why it’s important and how to measure it.

#### The DC Volt

How many times each day do you pick up a probe to measure a DC voltage? The meter reads, say 4.65 volts, and we usually accept it without question. But just what is a volt and how is it maintained? Here's a fascinating look at the search for increasingly more accurate methods of building a “standard volt.”

#### Small Logic Gates — The building blocks of digital circuits -  Part 2

Now that you have a handle on binary logic and how to make simple gate substitutions to solve your custom IC or obsolete part replacement problems, the next step is to put these gates to work for you. You know, the mundane tasks of add, subtract, multiply, and divide.

#### Small Logic Gates — The building blocks of versatile digital circuits -  Part 1

All logic circuits are based on two elementary propositions: AND and OR. Throw in an inverter gate (NOT), and you can solve any logic equation. Use these basic building blocks to get you out of a parts jam, whether it be for a new project or as a replacement device.

#### Magnetic Saturation And The 100 Amp DC Current Transformer

For most of us, measuring DC current means putting an ammeter or low resistance current shunt in the line. But now, you can build an adapter that can be used with your voltmeter and will measure 100 amps DC.

#### Turing Machines

The most powerful computer in the universe is actually the simplest. Explore the concept of Turing Machines and experiment with a simple Turing Machine simulator.

#### RF Interference

The phenomenon known as RF interference — RFI to its many friends and acquaintances —  involves interference caused by signals propagated wirelessly as radio waves. Most people don’t know (or care) about RFI until their garage door opener won’t work.