Bench Talk

Breadboards are fantastic for experimenting with a circuit design and testing components. Eventually, you will want to move to a more robust solution for a circuit that is intended to escape the confines of laboratory and bravely venture into the real-world.

It’s a great time to be an electronics engineer and an even better time to be a weekend warrior tinkerer. The line between these two worlds is rapidly evaporating as the tools that enable circuit design plummet in cost and skyrocket in capability. The most important thing that a product can do for us is to streamline our workflow while still delivering high quality results.

Mechanical buttons and switches can present unintended input trouble for embedded electronics projects. There’s an undesired effect known as “bounce.” What is bounce? When you press a button it sometimes does not cleanly change states. There is some electrical noise generated as the button rapidly oscillates between states immediately after a button is pressed but before it settles. Think of it like pulling a mass-spring system downward, letting go, and waiting for it to settle at equilibrium. Switches and buttons oscillate similarly, though the time to settle is measured in milliseconds.

Every now and then you come across a real gem on the internet. My father was a Coast Guard electronics technician early in his career, and it’s interesting to be able to talk with my dad about electronics stuff. This morning he sent me a link to a site with old Broadcasting and Audio Engineering magazines going back to the 1920s. I look at this ad in Figure 1 from Audio Engineering of June 1949 and have to ask: “What is a Triode?” Triodes are vacuum tubes, boys and girls. Isn’t it interesting that audiophile “purists” today would buy these very tubes for a glowing, more thrilling audio experience? Admittedly, tubes are more interesting to look at than solid state.

We built a smart mailbox, as related in an article, that had an ambient light sensor to detect when the mailbox door was opened. In that project we used a Vishay ambient light sensor (Mouser Part #782-TEPT4400) that acts very much like an NPN transistor, in fact the part is also referred to as a phototransistor. The difference being (when compared to a normal bipolar junction transistor) that instead of needing a base lead to setup the bias voltage, photons provide energy at the base-collector junction to turn the transistor on, thus allowing current flow from collector-to-emitter.

When you are just starting off in electronics, there are many design pitfalls that can lead to hours of frustrating troubleshooting. I highlighted the importance of troubleshooting in this earlier blog post regarding my work on the automated energy harvester. Many times these faults are fixed with a very simple tweak to the circuit design or component selection. One of the most basic of the faults is the infamous “floating pin” or “floating input” that can affect the I/O pins of digital integrated circuits.

I think we’d all agree that there never seems to be enough time to get everything we want to do….done. Engineers especially, face the double time pressure of meeting current project deadlines while at the same time keeping up with new technology and new products for the next project down the road. One of the things we at Mouser pride ourselves on is in making it easier for engineers stay up to date on new products and technologies through our website, technical articles, and newsletters. With the recent announcement of our MultiSIM BLUE tool, Mouser will now be able to directly help engineers with the first part of the equation: reducing their current time-to-market pressures.