Transistors are common and when pressing the switch, only one of the LEDs remains lit. What it will be is not possible to predict, which makes the game possible.
This circuit was published in an English magazine from 1980. The magazine no longer exists, but...
Found in a 1990s Motorola documentation, this high voltage circuit uses a PUT that is not a common...
This proximity sensor was found in a 90s Popular Electronics. The base is a PLL567 that operates...