This circuit is from an American 80's documentation. The circuit indicates when the voltage of a 9 V battery drops below 7 V. The transistors can be BC548.
The components used in this 80's circuit are uncommon today. The circuit is intended for...
May 2017 - The new high-speed Amphenol FCI Flex connectors with up to 10 Gbps data transmission...
This circuit turns on your car's backlight when a vehicle coming from behind gets too close to it...