Power Supply for Home lab?

The Main reason folks build there own is first and formost for the experiance  (Kinda New EE 101) , it can teach you a whole load about electronics, OpAmps, Power Transistors, Feedback, Transient Response, Voltage References, Temperature stability to name just a few and at the end of it you have something usefull

The second reason is because you have a few of the expensive parts laying arround already and there just the ticket to build a PSU on a budget, Im talking about perhaps a transformer from an old AMP, got a box to put it in, have an LCD or LED display to show the volts and amps (Or an analogue one) etc. Then the cost is minimal for the rest and you still get the benefit of learning and something usefull

If the reason you need one is purly professional / Must have one for the hobby but are an experianced EE then yes, often much cheaper to simply buy one, albeit low end.

My series on building one is aimed at the folks wanting to learn and gain the experiance, and now im going to extend this to making it fully programable, even remotly so it will potentially be comparable with ones exceeding many hundreds of dollars.

Peter

You can't go wrong with an LM317 operating in Linear regulation mode!

Making its voltage programmable is as simple as incorporating a I2C/SPI/Serial controlled resistor.

IDK (I Don't Know) about Photons possibly having Mass? At certain Levels/Situations Matter/Energy are interchangeable (E=M^C2 ). I guess I should continue that MOOC QM course I started  at www.coursera.edu. the QM course offered by the USA university of Maryland. I got as far as the Time-dependent Schrodinger Equation. But stopped b/c #1) I had got my Answer to the Q: Why QM? A (being): small semiconductor geometries are subject to QM Effects. #2) The math was getting Hairy and I suddenly remembered that I had given away my Math Bible, Krezszig "Advanced Engineering Mathematics" ^C2 . {sorry about the artifact, I am slowly starting to use the Equations Editor). W/O much success as evident by my mistakes here.

AAR Thx for posting the Ponder(ables)/In-Ponder(ables) to which I may/may-not be able to add to the discussion.

USCDADNYC, , NY NY USA

Kreyszig  - I'm keeping mine just in case - which shows what a hoarder I am since I have opened it exactly once with the intention of looking something up in the last 42 years !

MK

To MK:Was your edition of AEM "red" in color and about 6.5"x9.5"x2.5" (17x24x6cm). How I miss that book, I guess I can get a copy over the Internet.What book did you have for Fresh/Soph General Physics? What Calculus Text? US or outta country Higher Ed institution? I was BSEE 73' Syracuse University, JD 1990 NYLS.

You might saw I went from a 2nd Rate Engr School to a 3rd Rate Law School. My trajectory is definitely downward.

WRT "Hoarding", I take an approach similar to the NYS EPTL (Estates Powers, Trust Law) by analogy. You cannot execute a "Will" w/o knowing the metes & bounds of your Personal/Real (land) Property. Similarly, if you know what you have and can show a compelling reason to "keep" such, in my eyes, it is Not Hoarding. IDK about in other jurisdictions outside of NYS (USA), but this is pretty much English Common Law based. So you guys/gals in NZ and/or Aussie Land are covered

BTW anybody else going to participate in that "power electronics" MOOC at www.coursera.edu? We can use this forum to exchange Q's/comments. And maybe

exchange "GOOD" (if at all possible) Puns/Jokes. LOL

Hi Edward,

Unfortunately, E = mc^2 does not mean matter and energy are interchangeable.

This is a often repeated but wrong interpretation of what Einstein really said.

The full context of his equation says that the maximum kinetic energy E of a mass object m occurs when it is travelling at the speed of light c.

Mass and energy are separate items and both are 100% conserved in all reactions.

The equation also indicates that there can be NO massless sources of energy.

So the faster a photon vibrates, then the less mass it has.  This fact means that Planck's radiation law is wrong as he has higher frequency photons with more energy, which is not confirmed when you include the mass.

So if you are going to use Quantum Mechanics, you first need to throw away all of your massless objects and replace your discrete quanta as individual photons.

Oh and by the way, the standard atomic model is also wrong.

DAB

Seven!

It's my cat playing dice again!

DAB wrote>>...

Unfortunately, E = mc^2 does not mean matter and energy are interchangeable.

This is a often repeated but wrong interpretation of what Einstein really said.

The full context of his equation says that the maximum kinetic energy E of a mass object m occurs when it is travelling at the speed of light c.

ELY reply>> Forgive my stating the special case of Einstein's Famous Equation. Where v is negligible when compare to c. My bad.I guess I should stated the formula as: [having tbl w/ the equation editor, so this longhand] E = (M x c(sqrted)/ Sqroot (1- ( v(sqrted)/c(sqrted)). Is this what you are alluding to?

AAR I had to open up my Atomic Physics Text from Fall 71 or Spring 72 for this one

AAR2 I have just about exhausted my knowledge of (atomic/relativistic) Physics. Maybe I should proceed ahead (from where I stopped) WRT that QM MOOC. Could you (DAB) look at the curriculum to see if any of the concepts are worthwhile. Link is: https://www.coursera.org/course/eqp

Will any of this gobbly-gok help me understand what is behind the science/math of your Premise(s)/Theories ? Not to slight you, but I would prefer a Third Party Source for the Basic Science involved. Can you refer me to a "Mainstream" Source? I don't want this to become  a  PHD level learning experience. Just the Basics, if at all possible.

Two!

Cat's Eyes!

The cat's at it again!

As a forearm to the head - Ancient Egyptians measured Qubits in Cubits.

Both QEIIs are World renowned wave motion experts.

One QEII has no power and only reigns.

One QEII has no power and only reigns.

Does that mean that she does not precipitate?

DAB