This circuit is from an old Mullard (Philips) manual with applications using the 555. Choosing appropriately the resistors and the timing capacitors, the ranges obtained can exceed days.
July 2017 - Mouser Electronics has in its stock the new infrared (IR) emitters from OSRAM Opto...
The gated oscillator in the figure bellow tums on when a “0" Iogic Ievel is applied to its input....
In the figure we have a typical relaxation oscillator with a SIDAC as well as waveforms and...