This traditional monostable configuration is from a Motrorola documentation from the 70s. The integrated circuit is the Motorola version of the time and can be replaced by the current conventional 555. The circuit can be powered by voltages from 5 to 15 V and the trigger input is made by the negative signal transition. It is not convenient to leave this trigger input open. A pull-up resistor from 1k to 100k is recommended. The time of the output signal is given by the time constant R2 / C2.
