It features at least once in every Small Circuits collection: the 555 timer. In this simple circuit we give the chip a little more attention than usual (refer to ‘The Eternal 555’ in the Jul... Read more
This LED blinker manages with only a few components and is dimensioned to operate from an ac supply in the range of 4–16 V (6–24 V dc). As its current consumption is less than 1 mA, it’s als... Read more
This energy saving, a 12-V controller is nearly universally applicable. In addition to controlling battery powered lighting in a car, boat or caravan it is also quite able to control the spe... Read more
This infrared alarm can be used to detect persons passing through doorways, corridors, and small gates. The transmitter emits a beam of infrared light which is invisible to the human eye. Th... Read more
This is a tried and trusted design for the protection against overvoltages that can be configured for your own needs. The circuit can also be used to detect under voltages; in that case, the... Read more
This circuit is designed to help minimise the quiescent power consumption of PCs and notebooks, using just our old friend the 555 timer and a relay as the main components. The circuit itself... Read more
This voltage monitor circuit is based on an Elektor design with a 555 timer IC in the book 302 Circuits, which uses two LEDs (red and green) to indicate whether the voltage is within range (... Read more
The author wanted a very cheap and simple alarm for some of his possessions, such as his electrically assisted bicycle. This alarm is based on a cheap window alarm, which has a time-switch a... Read more
This circuit is a simple but high-quality preamplifier using a DS1882 digital potentiometer, a device specially designed for audio applications. The potentiometer is controlled over an I2C i... Read more
The RS Latch in the 555 Timer can be used with the Reset and Trigger inputs. The output is set or reset with the momentary inputs applied at these inputs. As the S and R inputs are controlle... Read more
