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.
This transmitter generates modulated infrared radiation and can be used as the basis for a remote...
This circuit, from the 1990 Motorola Dataar Databook, can use any LM139 series comparator. The circuit...
Up to some minutes intervals can be obtained from this circuit. The circuit can use a lamp (or...