If I want a 10 second delay, I can achieve it with a resistance of 100K and capacitor of 100uF [see RC time constant]: tau = 100e3 * 100e-6 = 10 seconds.
https://www.youtube.com/watch?v=GeveeSTyvGs
- Capacitor: 470mF, 100mF
- Resistance: 47K, 22K
- Diode: 1N4001,
- Transistor: 2N???
http://www.the12volt.com/installbay/forum_posts.asp?tid=91691
https://answers.yahoo.com/question/index?qid=20100910203520AAoZUtq
https://en.wikipedia.org/wiki/RC_circuit