Above is a comparator circuit which employs RC time constant to control the ON time of the output(please left-click to enlarge the image). Red plot belongs to the momentary-switch voltage versus time, green plot is the output voltage; and the blue is the current through the LED.
The load connected to the output will be a solid-state-relay such as: https://www.sparkfun.com/products/13015
I'm planning to drive a DC motor with that relay as a next step.
My questions are:
1-) When ON time I want the LED to glow, so I had to use around 270 ohm in the simulation(R6) to obtain a moderate brightness around 11mA. Bu then I had to choose R5 as 470 ohm where I normally choose it 10k in non-loading applications. Is the value of R5 pull up OK?
2-) Regarding C1: Should I use a tantalum capacitor instead of an electrolytic one for stability and long term use?
3-) R5 drives current all the time, so one has to switch off the power. Is there a workaround to prevent that? And LED current never goes to zero. Any ideas about these?
Note: I don't want to use an additional opAmp.