Just found this... is it useful?

When I was cleaning out our garage, I found a constant voltage (you set voltage, current is automatic) power supply with output adjustable 4.5 to 16 volts, up to 25 amps. What are the uses for this and is it worth keeping?

That sounds like you typical " lab bench power supply", if you like to experiment with bulbs or electronics they are very usefull. If you know what you are doing they also make great battery chargers - the emphasis on knowing what you are doing - you can easily get in sheep dip if not careful. I would never use one for Nicad or Li-on's

I use several for all sorts of electronic projects as well as a charger for 12V ( 13.8 V ) lead-acid cells.

Actually, I have used it before to charge 18ah AGM's for my powerpacks among other things. The thing is although I found it a long time back, kept forgetting to mention it here, plus my dad said I can have it now so... You are right about the charging as I wouldn't try a li-ion or even a ni-mh pack as they are both very tollerent to overcarging, trickle charging and over-current charging so yea... I was more interested in hearing about flashlight uses. Actually, I remember someone conducting a "destructive bulb test" and using one of these PSU's. Thanks for the help

very usefull, you can simulate a battery input on lots of stuff, without having to discharge $4 worth of cells to see how it reacts at different voltages. for example. a voltage controlling PSU is very valuable to testing a driver before you try and shove it in some light that uses battery.

you could wire it to light your whole house with leds

carefully enough and with enough control of that huge amperage , you could charge batteries too.

you could rig up a current regulator with some cheap parts, and be able to actually control the current.
then with a few meters in place you could have control and visual on the output.

That would be cool, backup lighting for the entire house consisting of 1 watt luxeons would be sooooooo cool... but impractical to set up

Now a new question: I have heard a lot about switching vs linear power supplies and quite frankly I don't know much about the difference/which is better, etc. My supply is about a foot by a foot by about 6 inches, weighs about 20-25 pounds and has 2 huge metal heatsinks on the back. As said before amps 20 contin, 25max volts 4.5-16. Thanks

big beasts that weigh a ton, are usually linear, ya computer power supply is switching, and see how small it is and can do hundreds of watts.

switching uses electronic methods to chop up the voltages , linear more often uses resistive methods and multi-tapping of the transformer and relays and all to change the voltage.
but they both have parts of each going on, like switching has limits so they still have multitapping of the transformer, so i dont completly understand.

linear is huge heavy and robust and lives forever, switching is electronic , smaller lighter, smarter newer , more stuff is going on electrically, and can fail more often. MY assessment.

Well, mine is very heavy... so I would think it is linear. Any other advantages besides being more durable?

D-Dog said:

Well, mine is very heavy... so I would think it is linear. Any other advantages besides being more durable?

Click to expand...

No RF noise, usually less ripple too. And far greater cost. They generally are far "cleaner" supplies - but hopefully someone who knows far more about them than I do will be along shortly.

D-Dog said:

Well, mine is very heavy... so I would think it is linear. Any other advantages besides being more durable?

Click to expand...

From Wikipedia, the free encyclopedia

A switched-mode power supply, switching-mode power supply or SMPS, is an electronic power supply unit (PSU) that incorporates a switching regulator. While a linear regulator uses a transistor biased in its active region to specify an output voltage, an SMPS actively switches a transistor between full saturation and full cutoff at a high rate. The resulting rectangular waveform is then passed through a low-pass filter (typically an inductor and capacitor) to achieve an approximated output voltage. Advantages of this method include smaller size, better power efficiency, and lower heat generation. Disadvantages include the fact that SMPSs are generally more complex than linear supplies, generate high-frequency electrical noise that may need to be carefully suppressed, and have a characteristic ripple voltage at the switching frequency.

---------------

Switching power supplies also play some fun games with the power factor on the AC side when used as AC to AC or AC to DC supplies. Not really a problem unless one is running a really huge one or lots of little ones like in a commercial environment.

PS: If you are a TRUE flashaholic, I would make sure there is a fuse in the output leads, because you are sure to do something sooner or later that would otherwise let the magic blue smoke out when trying something outlandish "just to see what happens...":devil:

PPS: NEVER EVER EVER put a low value resistor directly across the power leads - I don't think we ever found all the pieces of that sucker...

Enjoy!

Yea, I'll be sure to remember the resistor part Also, the entire PSU is fuse protected from the AC Side, 5amp slow-blow, and on the DC Side there is an automatically resetting breaker set at 25amps

If you decide you don't want it, I'll take it off your hands.

Very useful. I had to pay €70 for one, and it's only a five amp unit.
Only thing is, the minimum voltage is too high...