Who makes a high quality power supply?

Above mentioned should be good. Sencore makes high quality equipment also.

If you are looking for a high end power supply I suggest lambda url:

I have used them on various projects and found the supplies performed quite reliably. They come in rack mount, din rail mount and direct mount designs and several diffferent features such as programmability are offered.

Delta powersupplies are very good, but i do not know of they are avaialble inde US. It is a dutch company

Btw is not the same as the other delta power supply company which is a Taiwan based company

--
# A brainstorm to one person could be a slight draft to the other one.
# Cees Keyer, Amsterdam school of technology  (change -at- in @ in E)
# dept. Electronic Engineering, Weesperzijde 190, 1097DZ Amsterdam, NL
# cees-at-ieee.org  Voice: (+31)20-5951639, Fax: (+31)20-5951420

A power supply is a power supply. The cheapest one will do. I have good luck with $18.00 power supplies. They either work or they don't. People who pay $150 or $200 for a power supply are crazy. I've bought the cheapest for decades. It don't have to last 200 years, I won't live that long and it will be obsolete in a couple years anyway.

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Blattus Slafaly  ? 3     :)  7/8

I think you're taking a fatalist attitude. I have to disagree with you on a few points. Experimenters need a PS with constant current or current limiting capabilities (in case the breadboarded circuit is miswired or designed improperly). Metering is another necessity for experimenters. Yes, the user can always use bench meters for that, but it's sure handy to have those meters built into the PS. Keeps everything neat and easy to monitor, and frees your bench meters for probing the circuit.. Also, as a general rule, I like linear supplies for analog experimenting. Switchers can cause tremors in analog circuits that will drive you crazy unless you are aware of the source. Dual tracking supplies are great for analog circuits as well, since many designs need positive and negative sources. Again, keeps everything neat and easy to monitor. People aren't "crazy" for paying reasonable prices for good equipment. The extra cost of a well featured power supply can easily pay for itself by avoiding destruction of expensive components because the power supply couldn't limit or control the output current. Good power supplies don't become obsolete in a couple of years, as computers do. With proper use and a little care, they can last for decades.

Back to the OP's post... Constant Voltage (CV) operation is the basic mode of a power supply. It means that the output voltage is constant, regardless of current being drawn from the supply (within limits, of course). The output voltage of an unregulated supply will vary, depending on the current being drawn. Constant Current (CC) operation means that the power supply output is a constant current, regardless of the load resistance (again, within limits). The power supply will vary the output voltage on order to maintain the current at a constant level. If the unit has current limiting capabilities, that means that if you are operating in CV mode, and the current demanded by the load exceeds the supply's current setting, then it will switch into CC mode at the current limit setting, or it will shut down, causing the voltage to go to zero volts (or to a very low value). You set the current limit by setting the supply's mode to CC, then setting the output voltage to the maximum voltage that you want your circuit to feel. Short (yes, SHORT) the output terminals together, and set the current control to the amount of current you want to supply to the circuit, or for the limiting to occur.

If your supply has dual tracking outputs, that means the when you set the output voltage of the master output, the other output will follow that voltage setting. You control both output voltages with one control setting. That mode is usually controlled by a Tracking Mode (or similar label) switch.

That's pretty much the basics of PS operation.

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Dave M
MasonDG44 at comcast dot net  (Just substitute the appropriate characters in the 
address)

Some people are like Slinkies.  Not really good for anything, but they bring a 
smile to your face when pushed down the stairs.

Someone once told me, "buy good tools and only cry once" and I've found that to be consistantly true. Not once have I looked back and thought dang, I should have spent less money on this tool, but many times I've grumbled that I should have bit the bullet and splurged on a better one.

That maybe true how ever, a well designed power supply has much better protection in it to save your attached devices. crap power supplies tend to have poor regulation, voltage not in spec and when something goes wacky with them, they can take out the devices that are loaded on them or, they can just shut down silently or burn up with smoke and possibly flames.

Powers supplies are not perfect regardless of cost how ever, most of the higher end ones tends to guaranty performance and protection of your devices.

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http://webpages.charter.net/jamie_5"

No they're not. Things like regulation and short circuit protection can vary enormously.

And a cheap SMPS with cheap caps is not likely to last long. An analogue one with a poor transformer - the expensive part.

It would depend on the rating of it. $200 would be crazy for a 1 amp one - but not for a decent bench supply.

What becomes obsolete in a power supply?

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*If at first you do succeed, try not to look too astonished.

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Good question.. Maybe he is talking about a ATX PC power supply? All of my AT power supplies are unfortunately obsolete, at least for use in modern computers.

Indeed - but the OP talked about a 30v 10A CVCC PS. Not that I know what CVCC is - Google suggests it's the Cuckmere Valley Canoe Club. Perhaps they use some form of electrolysis to reduce friction? ;-)

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*Growing old is inevitable, growing up is optional

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Constant Voltage Constant Current. AIUI, the OP isn't talking about a computer power supply, or a benchtop piece of test equipment, but something to build into a chassis of a custom piece of gear. We stick with Lambda or Power One and have good results.

Correct regarding CV/CC but the OP is more than likely talking about a variable bench supply :-) He is also asking for help how to use it, and may be looking for what the difference between voltage and current and what an adjustable current limit (damm useful!), sense connectors and ground lift/connect may be used for.

Such things will be glossed over in the average chinese manual as those concepts are self explanatory for the engineer person specifying and buying such a unit. HP's (and most US written) manuals may be a bit more forthcoming?

His is probably like Mastech's

Anyway, My experience is with Thurlby (TTi) bench power supplies, don't know if these made it much in the US direction - but popular here in the UK for business and education use.

We need the OP back ...

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Adrian C

He stumbled in here from Google (so I'm among many who only saw replies) and probably can't find his way back.

Just curious what use a constant current constant voltage bench supply would be? Or does it mean *either* constant voltage or constant current?

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*If you try to fail, and succeed, which have you done?

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

For bench supplies, it's either, so I put a slash in my answer between CC/CV.

It's a supply where you wind up the voltage to what you want and then you set the current limiter to what you consider a safe maximum to the load circuit you are fooling with.

If the load demands more current than your limit, the supply will reduce the voltage to maintain the great law of Ohm. So essentially it will be delivering constant current (CC) to the load and flashing warning lights which will tell the user something is wrong with the circuit.

(Though in some circumstances ignoring the warning may be useful for things like charging nicad cells which should be charged using the constant regulated current.)

If you have no current limiter in force, then the supply works in constant voltage (CV) up to the point of smoke (or blown internal fuse or some other limiter) for excessive current delivered.

The following explains using a supply from HP for the point of view of an EE student.

Basics of Power Supplies - Use of the HP E3631A Programmable Power Supply

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Adrian C