Generating a delayed pulse with one 555 timer upon powering up the circuit
I created the following circuit that seems to be able to accomplish that task with just one 555 and no external triggers. 

Explanation of my circuit:


The left-side attempts to simulate a delayed trigger pulse.


R1-C1 is slowly decreasing the voltage from high to low and manipulates the length of time when output will be on LOW (~15 seconds)
R3-C3 is increasing the voltage but slightly slower than R1-C1 so that Trigger voltage dips below 3V but not for long

The right-side is a monostable 555 implementation


R4-C4 manipulates the length of time when the output would be on HIGH (~5 seconds)









simulate this circuit &ndash; Schematic created using CircuitLab

Here are the voltage measurements:



Here are the current measurements:



I think this implementation works but is there an easier way to accomplish that?