Solar flashlight (CB20488E)

This circuit charges a battery to power a flashlight at night. The circuit is from an English publication from 1991.

4001 External Trigger Monostable (CB15508E)
In the figure we have a circuit that fires from a positive pulse of short duration applied to its...
High Q Notch Filter TL071 (CB15307E)
This filter is suggested by Motorola's Linear Interface ICs of 1993. This same configuration...
1 kHz High Pass Filter (CB25997E)
This first-order high pass filter is applicable to any operation requiring a dual power source. It was...