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 Mullard circuit was found in a 1969 documentation. It uses complementary transistors on the output and...
This circuit generates signals from 0.01 Hz to 10 kHz, but uses unusual components today. The...
This filters blocks radio interference or noise coming from the AC Power line. Noise such as the...