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Math of the 555 Timer

Math of the 555 Timer

If you’ve been following along with the 555 timer series, this video describes how to derive the formula that describes the timing of the circuit. Starting with just 2 components, we’ll work our way to an answer.

How to Control the Duty Cycle of a 555 Timer

How to Control the Duty Cycle of a 555 Timer

Continuing with a focus on the 555 timer, this video tutorial looks at how to vary the pulse width of a 555 timer’s output. It’s all possible with just a a hand full components. By varying the duty cycle one may vary the blink rate on an […]

Cascading 555 Timers for Custom Blinking LEDs

Cascading 555 Timers for Custom Blinking LEDs

For the past several weeks we’ve looked at blinky LEDs, 555 timers, and resistors. This week it’s time to put it all together into an application. A YouTube subscriber suggested the project as follows: How would you go about having an led blink twice, then […]

Power Dissipation and How to Avoid Destroying a Resistor

Power Dissipation and How to Avoid Destroying a Resistor

As we learned from the last video, resistors are helpful when you want to limit current. They are also helpful if you want to divide a voltage level, but in order to do any of this, it’s important to understand all about a resistor’s power […]

How to Use an LED

How to Use an LED

In this weeks video we’ll take a look at how to use an LED. There are tons of LED related projects out there but what if you want to integrate LEDs in your own project? When your finished with this video you’ll be able to […]

555 Timer Output Stage (Lens Detector Part 2)

555 Timer Output Stage (Lens Detector Part 2)

The 555 timer has many uses and in this video we’ll explore two different ways to utilize the output. First we’ll see how the the timer can be used to source and sink current and secondly we’ll look at a way to use the timer […]

How a 555 Timer Works (Lens Detector Part 1)

How a 555 Timer Works (Lens Detector Part 1)

I am slowly in the process of developing another class, but this time I want to go about it a different way. I’m going to be letting everyone else in on the process. The coming class will include a lot of projects, so during the […]

How to Build a Passive Network Tap

How to Build a Passive Network Tap

In the course of my normal job, it’s surprising how often field expedient solutions are used to solve a problem. However, those field expedient solutions are impossible unless you understand the underlying principles involved. In this video I’ll look at Ethernet infrastructure, discuss how it works, […]

9 Volt, Battery Powered, Telephone Intercom System

9 Volt, Battery Powered, Telephone Intercom System

When I was developing the VoIP Fundamentals course, I wanted a demonstration to illustrate the simplicity of the public switched telephone network. After combing through the internet, I came across this ingenious little project. With just a 9V battery, a resistor, a telephone cord, and a […]

Auto Answer: Feature or Vulnerability

Auto Answer: Feature or Vulnerability

Auto Answer is a feature in many VoIP phones that allows the phone to go off-hook the very instant a call is received by the instrument. In this video we’ll look at how this feature is setup and talk about the security vulnerabilities. NIST Report: Link […]