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ArcticMyst Security by Avery

Suggestions on variable DC power supplies/oscilloscope discussion.

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Hey guys,
With the amperage requirements becoming greater with the new powerful diodes and drivers my mastech 15V/3A isn't cutting it.

I know in the past I have asked around but it was awhile ago.

Should I go linear or switching?

Jump up to 10A or should I look ahead and buy a 30/20A.

My thoughts are the mastech HY 3020D($215) possible a cheap eBay supply as an option.

Thanks,
Jefferson
 
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diachi

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Re: Suggestions on variable DC power supplies.

I'd go switching if possible - much less bulky, assuming you can find something with a nice clean output - no spikes and that kinda thing. Guess you could always add some capacitors to the output if you do end up with any spikes!
 
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Re: Suggestions on variable DC power supplies.

I'll check into that. Switching over linear.
I wonder at what amperage you could perform electrolysis to make hydrogen.
 

diachi

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Re: Suggestions on variable DC power supplies.

I'll check into that. Switching over linear.
I wonder at what amperage you could perform electrolysis to make hydrogen.


You can do electrolysis at low currents, but if you throw more power it at you'll obviously have a quicker reaction.

Switching supplies are generally lighter and more efficient. However, for noise sensitive applications the cheaper options often aren't great. I.e., ham radio - cheaply made Chinese switching supplies are a large source of interference, much less likely to have that issue with linear supplies or well built/designed switching supplies.

You can still get voltage spikes with linear supplies too of course.
 
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Re: Suggestions on variable DC power supplies.

I have a whole bunch of bench supplies I'm looking to sell. What sort of voltage/current are you looking for? If 30V/20A is what you're after, I've got a few I can give you a good price on.
 
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Re: Suggestions on variable DC power supplies.

I ignored when you took rep from my 2-year-old review thread, but now I've got more for my post offering help? Because "shipping is too high"? And now you're calling into question the quality of my supplies with no basis?

gajz5ct.gif


Not sure what your problem is, but you can have a minus 4.

Mr. Umbrella, feel free to PM me if you're interested.
 
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Re: Suggestions on variable DC power supplies.

I have trusted Cyparagon with a couple high dollar lasers in the past, he has a good reputation in this community. I don't think Cyparagon would sell me defective equipment. Naturally I am a bit leery of "cheap Chinese supplies " as diachi mentioned.

Pm incoming.
 
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Re: Suggestions on variable DC power supplies.

I ignored when you took rep from my 2-year-old review thread, but now I've got more for my post offering help? Because "shipping is too high"? And now you're calling into question the quality of my supplies with no basis?

(childish gif removed)

Not sure what your problem is, but you can have a minus 4.

Mr. Umbrella, feel free to PM me if you're interested.

Get over yourself. You give people unnecessary negative rep you will get it in return. Only difference is I'm not bitching about it in the open like you are.
I asked a question related to your products you mentioned because I was interested in one of them but now I don't want to do business with a crybaby.

And keep your friends from bothering me as well. I don't need more harassment from children in pm. Thank you.
 
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Re: Suggestions on variable DC power supplies.

I was interested in one

That's a lie.

You left neg rep because "shipping was too high" without even asking the shipping... BEFORE you inquired.

You give people unnecessary negative rep you will get it in return.

So you're admitting your negative rep was unnecessary. That says a lot about how petty you're being.
 
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Re: Suggestions on variable DC power supplies.

That's a lie.

You left neg rep because "shipping was too high" without even asking the shipping... BEFORE you inquired.

I knew the shipping price on your ebay page. Really now try to use more of that brain of yours ;)

So you're admitting your negative rep was unnecessary. That says a lot about how petty you're being.

It's not a secret that I don't like you and I admit to stooping down to your level a few times but remember that you aren't any better. So pointing your finger only serves to show the many more pointing back.

Really now I suggest you get over your feelings about me returning your neg rep. As I said, you risk getting one for leaving one. You've been here long enough to know that. Crying about it isn't going to make it better FYI ;)
 
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Re: Suggestions on variable DC power supplies.

Cyp's skilled and equipped enough to fully build, let alone repair, any PSUs he has or might need, even aside from his massive rapport with the community. I'd have no concerns buying such used equipment from him.
 
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Re: Suggestions on variable DC power supplies.

Alright, alright. no need to drag negative rep, personal attacks or topics from another threads into this.

As far as shipping goes the weight, size, and location would be a factor. I am actually close to Cyparagon, I'm in Joliet Illinois zip 60436. I haven't decided which PS of his to buy so when I decide the weight will be determined.

He said he will make a video showing the ps working and running through its paces. We'll see.
Thanks guys
 
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Re: Suggestions on variable DC power supplies.

I knew the shipping price on your ebay page. Really now try to use more of that brain of yours

I should use my brain? That's rich, coming from someone that has no concept of how shipping prices are generated on ebay. Sorry for not assuming you're watching all my online activity like some sort of predator.

Y'know, for someone that supposedly hates me so much, you stalk me an awful lot and pay close attention to everything I do.

It's downright creepy, this obsession of yours.

As I said, you risk getting one for leaving one. You've been here long enough to know that. Crying about it isn't going to make it better FYI ;)

Okay, so to be clear, you're completely okay with random acts of negative rep as retaliation? You won't "cry about it"? Odd that you would pick a fight in this regard, given the current odds of 94 to 805.
 
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ARG

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Re: Suggestions on variable DC power supplies.

Alright, alright. no need to drag negative rep, personal attacks or topics from another threads into this.

Agreed.

Cyp knows his stuff when it comes to power supplies, old grudges are irrelevant in this topic. Let's get this thread back on track.
 
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Re: Suggestions on variable DC power supplies.

Well, linear regulators waste quite a bit of power and will need overhead which may inhibit your ability to produce HV for certain applications. Not sure if it is relevant to lasers or not.
If your application is sensitive to EMI Noise or supply noise, go for linear. Certain LDO ICs [not sure if they come preassembled into bench supplies] can produce as small as 20uVrms at the output. I know of no SMPS that can get anywhere near that even with secondary filtering.

Another is size, how big is your workbench? :)
A 50W linear power supply is typically 3 x 5 x 6”, whereas a 50W switch-mode can be as small as 3 x 5 x 1”. That’s a 80% size reduction. On account of weight a 1000W Linear will need two guys, a hand truck, and some back-braces to install. A 2000W switcher can fit in a suitcase.

I'm not entirely sure how does a power supply react to a laser, as I can't imagine the load being a particularly inductive one. but there's the transient response of the power supply to consider, its basically how fast the power supply can react to a sudden load. Linear or Switching relies an an error amplifier somewhere to maintain regulation. If the output load quickly changes from say full load to half load, the output voltage of the power supply will spike until the internal control circuit compensates for it and continues to compensate until the voltage dips from overcompensation. Then the reverse occurs. This brief delay may mean nothing for resistive loads, but if your load is sensitive to voltage spikes, go linear. For a 50% change in load a switcher may take 3000uS to recover while a linear supply will likely recover around 50uS.

Finally, since you mentioned you'll be doing experimentation. You would also have to keep current leakage across the Earth line in mind. In switchers there will be high voltage bipolar caps across the AC bus to Earth for reasons to dampen or eliminate feedback noise, but these caps do leak a tiny amount of current through Earth. If your oscilloscope uses Earth as the ground reference, you might get really bizarre readings.

Just a few things to think about. I'm sure someone who is actually been in the industry and not a hobbyist will chime in with better answers
 
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