Most electronic devices today have a single button you push to turn them on and off. Think of your cell phone, laptop, and even your TV. There is no toggle to flip, no knob to turn back and forth, nor slide switch to move. So, how do you get one of these power buttons into your project so your latest gadget can sit next to your other devices without the embarrassment of a toggle or slide switch?
Design and construction of a basic analog radio has changed drastically over the years. Radio architecture has evolved from multi-tube designs, to transistors, to integrated circuits, and now, today, to a single chip. Here's a look at how digital techniques have changed and improved analog radios.
Many techs of yesteryear built their projects on a breadboard, then would transfer everything to a mirror copper clad board. Here's everything you need to know to use this timeless technique to wire up circuits for prototyping or functional applications.
The Raspberry Pi represents a breakthrough in low cost computing power. Get a piece of this popular DIY action by learning how to cook up your own RPi to start experimenting with.
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.
Perhaps one day soon we’ll have a battery that displays no “memory” effect; can be completely discharged or overcharged without harm; and require no complex computerized management system. Does such a battery sound like too much to hope for? Thomas Edison didn’t think so.
This article shows you how to build a really cool 3D cube with a 4 x 4 x 4 monochromatic LED matrix which has a total of 64 LEDs.
Ground faults are a curse to fire alarm systems. Even a small amount of current leaking to ground somewhere in the building can cause an unscheduled fire drill. Worse yet, a second ground fault somewhere else in the building can short out the whole system. An easy modification allows a low tech analog ohmmeter to detect insulation faults that a high tech digital ohmmeter fails to find.
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.
The clock is made of a collection of counters. Counters made by a chain of n flip-flops result in binary ripple counters capable of dividing by 2n. A four flip-flop counter naturally counts from 0 to 15. To make it count from 0 to 9, it needs some steering logic on the flip-flop toggle inputs.
