This low power circuit was obtained from an American 80's documentation. The circuit indicates the voltage of a battery being trimmed by the trigger point. The transistors can be the BC549.
This circuit was obtained in an old manual valid for practically any type of operational...
This circuit was obtained from Radio Electronics magazine, October 1987. The circuit uses a triac...
This three-digit counter (up to 999) was found in documentation from the 1990s. It uses TTL...