Whether you are just getting started in electronics or you have boxes of parts, it is good to know what are the most critical parts to have in your kit. James asked the element 14 community for what they considered to be essential passive components like resistors, capacitors, switches, wires, and even diodes. In this video, he consolidated their puts and explains what to think about when buying these parts for your kit.
Learn how to use an LCR meter, such as the Tenma 72-10465, to measure reactive components. An LCR meter uses an AC signal at different frequencies to characterize capacitors, inductors, and even resistors. They can also provide impedance measurements. These include phase angle, ESR, quality factor, and dissipation factor. You can even use the 72-10465 to sort components by their tolerance range.
A question came up on IRC regarding how to PWM a 3-pin PC fan with an Arduino using analogWrite(). Controlling the fan was seemingly straightforward. The problem was that the hall effect sensor, or TACH signal, was incredibly noisy. The noise made it impossible to measure the fan’s rotation. Working through the question, I found three issues to tackle:
- You need to use a PNP transistor
- Filter capacitors help
- Create a non-blocking RPM measurement (with millis())
This post addresses all three issues regarding how to PWM a 3-pin PC fan with an Arduino.
Whether you are an engineer with enough experience to be called a graybeard or a novice that keeps grabbing the wrong end of a soldering iron, there is one component that eludes everyone working in electronics.
It’s the humble capacitor.
A seemingly simple device, turns out, to be incredibly complex. While the basic electrode-dielectric-electrode structure sounds simple, the materials used in that structure drastically changes the characteristics of the device.
[featured-image]KEMET Engineering Center Screenshot, Courtesy of KEMET Corporation.[/featured-image]
To save time, breadboard pins or just lack of knowledge people try to skip adding even one decoupling capacitor to a circuit. Either on IRC or in Forums you can almost always see it coming: “randomly, my circuit stops working” And then, “what do you mean a decoupling capacitor?” question.
While working on breadboard Arduino, I came across some unexpected measurements. Initially, the only capacitors on the breadboard were the two 22pF from crystal to ground and the capacitor connected to RESET for Auto-RESET.
Keep reading to find out what happen when I added a 100nF and a 1µF cap. A bunch of scope traces and surprising results follow.