This circuit is used in transceivers, enabling input selection by diode switching through polarity reversal. The circuit is from an old American documentation on telecommunications.
This flasher with a well-known configuration was suggested by a 1977 publication by Radio Shack. The...
In the figure we have a practical idea for using the good junction of a partially burned...
The CMOS TLC555 [equivalent to the bipolar 555] can be used as a monostable in the configuration...