Upon entering a cell, a virus often becomes dormant, turning off its genes and laying low until awakened by some trigger from its environment. When that trigger is pulled, the virus quickly ramps up ...

Available integrated circuits can let you program a current limit, but they generally involve microcontrollers or data converters (or both). As an alternative, the circuit of Figure 1 lets you program ...

There have been many different ideas presented for increasing the acoustic output of a piezo buzzer or ultrasonic transducer. Most of them involve rather complicated circuitry that drives up the total ...

It is a running gag around here that whenever a project posts, someone will inevitably point out that it could have been done ...

Lighting a string of LEDs at a constant brightness requires driving it with a regulated current. A boost converter is commonly used to step up the voltage to a level high enough to bias the LEDs on ...

An RC circuit in series with the coil allows full-current turn-on for reliable relay operation, then reduces the current to save power. Fellow engineer Sanjay R. Chendvankar of Mumbai, India, recently ...