Keeping tabs on relative humidity and temperature is important in a variety of situations. The DHT22 is a recent contribution to the lineup of joint humidity/temperature sensors, and is particularly attractive to DIYers thanks to its low cost. Uncover its secrets to get it working for you.
I examined the almost perfect circle surrounding a stylized “M” (for Motorola) that was branded into the end of my index finger after touching the case of a power transistor to see if it was “warm.” This was my introduction to “heatsink selection for power semiconductors” I received as a young experimenter building a power supply — a lesson I have not forgotten several decades after the event.
Electronic designers are familiar with the apparent perversity of Nature in the tendency of amplifiers to oscillate and oscillators to amplify. But even the beginning designer knows that questions of oscillation and stability involve feedback — that ubiquitous structure in natural systems and many man-made ones — whereby a fraction of the system’s output energy is fed back to the input to produce useful effects.
Understanding And Designing With The Ever-Useful CMOS Timer: Not as commonplace as the operational amplifier, the integrated circuit CMOS timer — such as the ICM7555 and TLC555 — has nonetheless found a secure niche in electronics. Why is this?
Crystals That Make The World Go ‘Round: Strike a crystal goblet with a spoon, and you immediately have both the attention of your guests and the sympathetic resonance of other goblets on your sumptuous holiday table. What is happening here? Well, you have created a crystal oscillator that generates acoustic waves in the air.
Some people tend to shy away from using surface-mount components in their projects. It seems to be too difficult or needs an array of specialized equipment. In the past, I found myself in this same mindset — wary of using these types of parts. That all changed.
Power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) have a lot of nice features that seem to be overlooked. Let's take a close look at these useful devices, then in Part 2, we'll use them to build a couple of handy projects.
This transistor was actually the first type of semiconductor amplifier predicted theoretically at Bell Labs, back in the 1950s, but it was not developed into a practical device until after the bipolar type had become popular. However, FETs have now become the most common type, with tens of millions of them in each microprocessor IC chip.
Open a parts vendor’s catalog to the capacitor section and you’ll find an amazing variety of choices. Why are there all these different types? Rest assured that there are perfectly good reasons for each. Find out why and how to tell what type is right for your project.
An ohm is an ohm, right? Not so fast — there are many different types of resistors. To insure that your circuit works and stays working, use the right type of resistor. In this article, you'll learn about the common types of resistors and their special characteristics.