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.
For signals up to about 500 kHz modulated in amplitude and transmitted by the power network, the...
This circuit, found in a 1995 documentation, is intended for switching composite RGB video signals...
This low drift or offset circuit is from an 80's documentation. The configuration can be made with...