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 circuit was originally designed to be used in the car. When talking, the sound of the voice...
The transistor for this flashlight brightness control may be the BD135. The circuit is from 1978...
We found this circuit in Radio Electronics magazine from October 1966. The circuit uses a 15 V...