This circuit found in a 1964 US publication reverses the signal level by providing 9 to 0 V outputs from 0 to 9 V signals. Transistors may be equivalent.
The operational amplifier using this 80's circuit is a double 741 of the time. The circuit may be...
Mouser Electronics has in stock Amphenol FCI Booltrack ™ connectors for robust connectivity...
This circuit can be used to add a delay to a logic signal as shown by the input and output...