Both of which do not sell the SL100, 2SD313, BD139 or BC301. I would really appreciate it if the experts here can help me find a replacement that is available from the above two sites and works for the "Automatic Room Lights" project.
The SL100 is a high frequency transistor, this isn't needed to drive a relay. Looks to me like any general purpose NPN will work. (2N3904, 2N2222 etc.)
There is certainly plenty of circuitry to get your teeth into here ...
Yep, any old small or medium power NPN transistor should work.
I can't help thinking there is a *much* simpler circuit to achieve the same results, maybe based around an up/down counter thus eliminating one of the 4017s and all that 'compare' logic after it.
The site has a search engine that especially looks for part replacements. I went out and bought a BD137 and NTE152. Hopefully one of them will work. From the responses, it looks as though they will.
In regards to a simpler design, it's way out of my league. Anyways, it looks more sophisticated this way, maybe I'll get a high mark for it