I have a DC supply (5 V) to turn some circuit on and in that circuit there is a module which uses a specific mechanism (i.e. a 2 seconds width high pulse) to turn on (even if a supply is connected, that module will turn on only by this mechanism i.e 2 seconds pulse).
So I want to generate a pulse (high) of 2 seconds when that DC supply is turned ON.
I know we can do this using timer ICs like 555 timer, or any microcontroller, or using gates (but this uses IC, RC components etc,) but I was wondering if I can make a circuit using only R and C as components.
Problem:
When DC supply (5V) is turned ON, the circuit gives '1' (5 V) for 2 seconds and then give '0' (0 V) for the rest of the time supply is connected.
Question:
Is there a solution where we can implement this without using any microcontroller, timer IC or any delay IC? The circuit can contain resistors, capacitors, transistors or diodes etc.
Edit:
This pulse is used as a trigger to turn on the module, there is no load attached to that pulse. Currently, there is a push button that does this job. I have to press that button for 2 seconds to turn that module on. I want to remove that button and want to automatically turn the module on when supply is connected.
Best Answer
This will provide sharp trigger pulse with hysteresis; you can finetune the time by Rp:
At time zero the supply turns ON and provides a 5V two seconds single trigger pulse output.