This circuit was found in a 1964 Electronic Design. It generates opposite phase signals from an input signal. Modern equivalent transistors can be used in the same configuration.
This light sensor shield, with operational and TTL compatible output or microcontroller was found...
This circuit is from a 1980s Motorola documentation. The circuit can be made with modern...
The number of pulses produced by this circuit depends on the switch pressed. The circuit is from...