We found this circuit in a publication from the 1970s. The circuit detects when the pulse duration is greater than 1.1 x R1 x C1. The transistor can be 2N2222 and the supply is made with voltages from 5 to 15 V.

We found this circuit in a publication from the 1970s. The circuit detects when the pulse duration is greater than 1.1 x R1 x C1. The transistor can be 2N2222 and the supply is made with voltages from 5 to 15 V.