| The circuit shown here combines the functions of a low-pass filter and an integrator, presenting a novel approach to creating a precision 50...
| The circuit shown here combines the functions of a low-pass filter and an integrator, presenting a novel approach to creating a precision 50...
| Power shortage problems arise when too many USB devices connected to PC are working simultaneously. All USB devices, such as scanners, modem...
| This circuit eventually surfaced while pondering over the design of a current indicator for a small power supply. Fortunately, it proved pos...
| This circuit was designed to ‘baby-sit’ SLA (sealed lead-acid or ‘gel’) batteries using freely available solar power. SLA batteries suffer f...
| At the end of his scientific research carried out in 1887/1888 Heinrich Hertz was able to prove the existence of electromagnetic waves and d...
| It is often necessary in complex designs to provide a sequence of reset pulses to different parts of a circuit to ensure the whole design fu...
| This circuit was designed to produce an audible alarm when the mains power is interrupted. Such an alarm is essential for anyone whose livel...
| Some relays will become warm if they remain energised for some time. The circuit shown here will actuate the relay as before but then reduce...
| This circuit is innovative in more than one way and therefore belongs per se in Elektor’s Small Circuits Collection. Firstly, it demonstrate...
| Most darkness activated alarms employ opamps and some logic ICs. Here, a less expensive approach is shown based on the eternal 555, this tim...