With no capacitors you should be able to observe full-wave rectified at twice line frequency with 34V peak.
With one 2200uF cap you should see virtually no ripple.

 

Thanks for that. I did what you said.

rectified line w/no caps:



with a cap:



I'm now feeling what I've feared the entire time. Everything has been working fine and I just don't know at all how to test and measure with my meter and scope. Well, I know a little more now. When the book said to use the VAC setting on the multimeter to check the ripple, I thought that would be the same on the scope. Now I see it. Literally. You see the AC ripple on the DC signal when looking on a scope. That's, like, what it's for. *face palm*

Anyhoo, I'm going to order an analog meter. While waiting for that to come in, I'll start putting the regulator section together on a board. I got a 317/337 pair for next to nothing locally. Only lightly used they seem. What could possibly go wrong?



Thanks again for chiming in and helping me out. This is a great community. I hope I can return the favor one day as I learn more.

 

What can go wrong? Lots. Especially when you purchase electronic components from RS. I was told that semiconductor rejects at the factory went into a bin labelled RS.

 

Why is your full-wave rectified signal inverted?
Are you probing the -ve side of the bridge for this test?

And that sine wave looks very distorted.

 

I didn't purchase it from RS, but it's very possible that's where it came from originally. Maybe I'll order a new pair.

It was the -ve side. Physically, the wire was much easier to get to than the +ve side, and I didn't think it would make a difference. The +ve was still attached, so could that be why it was distorted? It took a good long time just to disassemble that little bit and then put it back together. Perhaps I was a bit half-a$$ed. But, if you think that I just just take apart the whole thing for sure to test, I'll say I've learned my lesson.

 

Ah yes. Re reading your suggestion, you said remove ALL the caps.

Ugh. I feel like I'm in 4th grade again. Sorry. I'll do it again and do it right.

 

Here it is, from the rectifier, with no caps attached:

 

Looks ok.

As I said before, 4700uF is more common than 4400uF.

What is your current demand on your load and how much ripple are you willing to tolerate?
Put one 2200uF on each side of the bridge, one on the +ve side and one on the -ve side.

There should be no ripple on either side, +ve or -ve, with no load attached.

 

How much ripple I'm willing to tolerate? Unfortunately I don't have enough experience points to be able to give you an answer. I'm merely following directions out of a book. (But yes, I am trying to learn, so it's more than that.) That said...before I start taking caps off (those lugs are cramped and stuffed full of components and solder)... I've done some other measurements that make me feel this scheme with the caps is working just fine. The book says that I should have an AC component of 5-20mVAC. When I measure with the nice fluke I borrowed, it tells me I've got less than 1mVAC. Maybe that's not so unrealistic?



Perhaps since I have four caps of 2200uF in parallel as opposed to just two 4400uF caps, it helps take out ripple even more than what the author originally said.... Yes, I'm being a little speculative, but I feel that the fluke is giving me a good reading. Also, I did a AC frequency check using the fluke (a little trick the owner of the nice fluke told me to try) and I'm getting a goose egg on both sides, which would imply no ripple, yes?