Very Disapointing New Bench Power Supply!

superwarp1 posted:

The one on the right has been bullet proof.  Sadly you can’t get that make anymore 

I have (had) the one on the left - it crapped out after 18 mos.

Brendan 

Brendan posted:

superwarp1 posted:

The one on the right has been bullet proof.  Sadly you can’t get that make anymore 

I have (had) the one on the left - it crapped out after 18 mos.

Brendan 

Brendan; you did well I think. Mine crapped out after about 18 seconds!

Rod

I don't use mine enough to know if it'll crap out after a spell.  So far, it's worked fine when I've used it.

Well my old USA Made Astron VS-20M-20V DC power supply was bought new back in 2006 and works just fine. I also have the schematic for it incase it ever needs servicing...of course can also just send it back to Astron for repairs.

It may be slightly off-topic, but my go-to bench power supply is an old "Electro" Model EFB made by Electro Products Laboratories out of Chicago, IL. 

Can't locate a date on it, but I’d guess it was manufactured in the late '40's or early '50's and still works great. It belonged to my father-in-law who was a ham radio operator and tv, radio and general electronics tinkerer and, yes, you will get a hernia lifting it !!

I'

gunrunnerjohn posted:

FWIW, my identical supply has been fine as far as reliability goes.  They do have the same comment about no load at startup, but they make a statement that it may get a voltage spike when you power it up.  I haven't seen that issue surface, but I am careful in connecting it to anything critical.

How about connecting a couple of capacitors across the output? Would that solve the spike issue? Maybe if it did, the original designers would have included it.

I don't think so, that may actually force a failure because of the surge current.

gunrunnerjohn posted:

I don't think so, that may actually force a failure because of the surge current.

I was thinking of a .01 or a .001. That might eat a spike, but should not create too much of a surge. But again, the original designers would have included that if it would have worked, no?

So John, how do you use it? Do you turn it on, turn down the voltage to zero, hook it to the circuit, then turn the voltage up? That seems like a hassle. Or do you hook it to the circuit and then just turn it on, or what?

Or has the spike they warn about never affected anything you were working on?

I doubt a small cap would have much of an effect.  Remember, you're talking about a P/S that can deliver to amps, when it surges, it has a lot of energy in the surge.

As for how you'd connect it, you'd have to evaluate what you're testing.  Since I use it to run DCS locomotives on DC on the bench, the spike is of little consequence IMO.  I did hang a 'scope on it and didn't see any massive overshoot  The overshoot may only happen in certain circumstances, hard to say.  Personally, I have the voltage set and just hit the power switch when I use it.

One other issue with many switching power supplies is their startup load capability.  Some have trouble starting up with a heavy load, another reason for their caution, depending on the actual design of the electronics.

gunrunnerjohn posted:

Rod, I'd simply put it in eBay's hands and stop dealing directly with the company.  For defective products, they normally are quick to simply refund your money.

I'll second that. File a complaint thru eBay and you will receive credit quickly from Paypal.  Works every time.

Gerry