This circuit with zener diodes was found in documentation from the 90s. The zener diodes determine the lighting point of the LEDs. The circuit is for 12 V automotive batteries.
This trigger uses two transistors having been found in ancient French documentation. The circuit is...
This simple alarm with latching uses a relay as the main element. The circuit is from a Radio...
This sensitive signal follower with an LM386 integrated circuit can be used in both audio and RF...