Stan, Today's project is the Circuit #2 you posted a pic of above, that Rod has already tried. The one with 4 transistors.
And FWIW, I tried the circuit with the LM339 and was unable to make it work. I checked and re-checked all my connections and they seemed to be correct. Even tried a couple of things I thought might make a difference and they did not, still didn't work. I don't think it was due to a mistake on my part? I set it aside and am going to check it one more time in a day or two before giving up?
Rod is ahead of me in trying some of the others. I have to agree with him that the first circuit we came up with (R5.4 posted here) earlier in the thread seems to be the one we are leaning toward.
I also broke down and got some 7808 & 7809 voltage regulators to add to my 5 & 12 volt versions. I went all out and used a US seller (about 30 cents each, still free shipping). And they are already here! So I can now experiment with those too.
Also, for anyone else having trouble with the link to Rob Paisley's site, my earlier problem was Chrome and the website being http: instead of https: Chrome wasn't allowing everything to come through until I told it the site was safe as it wanted the site to be https: There are settings in Chrome to allow an http: site, but they are apparently turned off by default.
I hadn't run into this previously? Thought I would post in case others had problems. Also, the http: site worked just fine with IE 11, no special settings needed.
