Voltage References - The Modular Bench Power Supply ++

RE: Voltage References - The Modular Bench Power Supply ++

e14 Contributor — Thu, 19 Nov 2015 02:18:36 GMT

Hi Peter,

Thanks again for the wonderful videos. Please excuse my ignorance, and also the fact that this is not the main topic in your presentation, I thought a while, but could not figure out how you are connecting the power supply and the signal generator to test the v. references. I could be totally mistaken here, but I thought you had mentioned that the ground leads of the two instruments are connected, in which case the 20V potential on the output of the p.sup. should drive some current into the signal generator oscillating at 5 V p-p. If the two are connected in series, then the same current should go through both of the instruments. What is the point I am missing here?

I am assuming here that a p.sup or a signal gen. should not be connected to a circuit that in itself has a voltage source, maybe here I am mistaken.

Regards, Gilbert

p.s. I am studying the op amps videos, you are going through an actual hands-on design and build procedure in detail, which is unique and great.

RE: Voltage References - The Modular Bench Power Supply ++

jw0752 — Tue, 30 Sep 2014 15:22:13 GMT

Thanks Guys - It seems that I looked at the Data sheet before I went searching for a source and price and inadvertently added the "Z" to the part number. These links look much better.

John

RE: Voltage References - The Modular Bench Power Supply ++

jw0752 — Tue, 30 Sep 2014 06:17:01 GMT

Hi Peter, I was looking into getting one of the REF02Z voltage reference chips you mentioned but, at least here in the States, they are not common or cheap. DigiKey has some for $22.50 each and Newark lists them for $20.50 but doesn't have any in stock. Why would there be such a difference between Canada and the US on price? As you mentioned I am sure there are many substitutes.

John

RE: Voltage References - The Modular Bench Power Supply ++

Robert Peter Oakes — Tue, 30 Sep 2014 01:35:31 GMT

Thanks for all the support so far, next up, OP Amps and I welcome the "Negative Feedback"... "Did you see what I did there... negative Feedback.. Op Amps [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-51c6a146-ab07-43a2-b5a6-caaf3f9c4e73/contentimage_5F00_1.png:16:16]. No , ah well, you will

RE: Voltage References - The Modular Bench Power Supply ++

DAB — Mon, 29 Sep 2014 20:54:26 GMT

Good Job Peter.

You did a good job describing the circuits and the contributions of the components.

I did not know that you had so many multimeters, but if I count my old analog ones, I can probably beat you. [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-51c6a146-ab07-43a2-b5a6-caaf3f9c4e73/contentimage_5F00_3.png:16:16]

DAB

RE: Voltage References - The Modular Bench Power Supply ++

shabaz — Mon, 29 Sep 2014 10:45:10 GMT

Hi Peter,

Glad the project has started!

As an idea, perhaps the vids could be chopped up into 6-minute versions with descriptions, so people can immediately jump to the relevant one, (or alternatively have a 6-minute "highlights" version too).

Regarding the voltage references, I too agree with you, and would avoid zener diodes. You might also want to check out the TL431, cheap yet high performance - initial trimming is 0.5% (so that may rule it out depending on needs) but on most other points it should fare well. Still there is such a choice that everyone may select differently!

By the way, forward to the next instalment - I have a main PSU, but my current home-built dual supply is pretty basic - based around dual LM317. So I'm keen to get building : )

RE: Voltage References - The Modular Bench Power Supply ++

michaelkellett — Mon, 29 Sep 2014 07:40:15 GMT

It's such a shame you've done this as video - I'm sure you've put a lot of effort into it but I can't possibly afford 90 minutes to look at it. I also suspect that it's much harder for those where English is not their native language.

It also means that it's not cut and paste-able or searchable.

BTW, a typo has crept in to the preamble and there are several references to silicone when you mean silicon.

RE: Voltage References - The Modular Bench Power Supply ++

jw0752 — Mon, 29 Sep 2014 06:11:25 GMT

Thank you Peter, As usual an excellent easy to understand presentation.

John