Category Archives: Electronics

We have recently experienced some laboratory failures during humidity testing that were due to corroded connectors (Figure 1). The connectors had corroded after they become wet from condensation that accumulated on the cables and rolled down to the lowest point on the cable – where the connectors were. Continue reading →

Yesterday, I had a question from a reader on how to develop mathematical formulas for different potentiometer tapers. Normally, I would simply answer the questioner without a separate post, but my solution for this particular question provided a nice illustration of basic coordinate transformations. Since I have not shown any coordinate transformation applications in this blog before, I thought it would be worthwhile to make a post of my response. Continue reading →

Electrical engineers design their circuits to work under "worst case" conditions. This means that the circuits will meet their operational requirements when built with any possible mix of components and environmental conditions (Figure 1). Determining the worst case conditions for a complex system can be difficult, especially for analog systems. There are numerous approaches to worst-case circuit analysis. One approach that I use is called Extreme Value Analysis (EVA). Continue reading →

This is a circuit designed by Stephen Woodward that I saw years ago in EDN. I originally was interested in the right-hand side of the circuit, which measures the real power usage of the load. I now have an interest in the left-hand side of the circuit, which measures the Volt-Ampere (VA) usage of the load. I will present an abbreviated analysis of the circuit Continue reading →

I previously wrote a blog post about how to select components for a Schmitt trigger circuit using a comparator with an open-collector output. An engineer stopped by my cube yesterday and asked if I could write-up the same analysis for a Schmitt trigger circuit using a comparator with a push-pull output. This post will provide that analysis. The only thing unusual about the circuit is the use of a Zener diode as a voltage reference instead of the more commonly seen resistor divider network. Continue reading →

An engineer stopped by today and had forgotten how to use Mathcad to solve a pair of circuit equations to determine termination resistor values. I stepped in and helped. As I looked at the problem, I thought it might be useful to cover on this blog as a tool demonstration. Continue reading →

One of the most common diagnostic functions requested for an electronic system is to measure its own temperature. We want to know the hardware temperature when a problem occurs because many system characteristics are affected by temperature and temperature may give us a clue to the problem's root cause. Continue reading →