Can you recommend a great power supply for lab experiments (possibly AC and DC)?

Question

I am looking for some suggestions on a really good experimental power supply I can buy for some simple benchtop experiments. Can someone recommend a good one or a good supplier?

I went to a surplus store, and they had a brand new single for $200 with 5A/ 0-30V DC with meters...The guy said AC ones are hard to get.
I wasn't that impressed.

I wonder if they sell ones that can do 0-120v DC and AC (adjustable frequency, etc)? Dual? In sort of the same price range.
Or would I have to build circuits do to this? Maybe I need a signal generator instead?

It seems strange they wouldn't have a good one like this on the market for a reasonable price, that can do a lot of stuff.
I got a great digital multimeter for example for 80 bucks that can do just about anything.

I have an EE degree, but haven't touched the stuff in 15 years. (done only software stuff). I would like to try some very simple experiments and play with diodes, coils, and transistors

Thanks for any pointers!

Answer 1

Usually, you won't find both AC and DC output in one power supply. Most benchtop supplies are DC output. You usually have choices in the number of output voltages, the output current of each, and some other features which usually aren't that important (programmability). I personally own an Agilent E3630 supply which offers three output voltages (each is DC) and is fairly low noise in its output (good for analog circuits). We have some similar supplies on our benches at work from a different manufacturer, but these triple output supplies normally cost around $400 on up.

I attached a website link below for a company I have used to buy test equipement including power supplies.

If you need an AC supply at 60 Hz (assume you are in US), then you can find a variable transformer, also known as a Variac, and use it to step up or down the line voltage. These work at other frequencies too (50 Hz). Variac is trademarked, but is often used as a shorter name for variable transformers. Cost of one of these is on par with the cost of a good DC bench supply. Be careful on the wiring if you choose to do this!!

Hope this helps...

Answer 2

A lot depends on what sort of experiments you have planned. You need to come up with some specs that suit your own needs. Without giving us details about your plans, it is tough to give you a simple, definitive answer.

That being said, here is what I can tell suggest:

1. A variable voltage supply for basic analog circuits. Perhaps 0 to 15 or 20 V, 1 to 1.5A. If you have something specific in mind that requires more voltage, then get more voltage.

2. If you plan to use op-amps, then a +/-15V supply, 100 to 300 mA. Not that you need that much current, but it isn't much and could become useful for other things

3. For digital circuits, a 5 V supply is a must-have. You probably wouldn't need much current for digital stuff, but if you see some multi-amperage supply for a good price you might as well grab it, if you have any high-amperage projects in mind.

Hope this helps, or at least gets you started on the right path. You might find low prices at eBay.

p.s. By the way, I just use Wall-Warts and fixed voltage regulators for my own home projects. A good power supply can be expensive.

Answer 3

the advantages of DC over AC is it may carry greater capability in line with conductor. additionally in the time of long distances the place there is a great volume of capacitance interior the line. As we properly be conscious of, DC has a tendency to forget approximately capacitance different than to cost it up the place as AC will bypass via a capacitor or act as though it does, ensuing in capability loss. DC voltage does no longer have a corona discharge as does AC. it somewhat is to assert AC is leaking out everywhere. 800,000 volts seems the right end for DC,and is with regard to the breakdown voltage for the semiconductors used to transform it to AC. even in spite of the indisputable fact which you would be able to place those factors in series so as that each and every semiconductor has a share of the finished volume of voltage. Now the share question. 80% greater capability must be transmitted using DC, and is inverted to AC using a static inverter.

Answer 4

A Variac, mentioned in a previous post, is the name of a particular make of variable transformer.

They are rather expensive and you are unlikely to find it much use.

The only other a.c. supply frequency, apart from 50Hz in some countries, is 400Hz which is sometimes used in aircraft. Again, it is unlikely to be of interest to you.

Your money will be better spent on something else.

Answer 5

Thank God for EBay :P.

Here are a few results, I hope that I helped. I too would enjoy experimenting a little with electrical components.

A little red one, supposedly silent with 800 rated watts and 1kilowatt max output.
http://cgi.ebay.com/SILENT-1000W-1000-WATT-GAS-GENERATOR-AC-DC-OUTLET-1-KW_W0QQitemZ320007209103QQihZ011QQcategoryZ106437QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Another, rather large, but this one looks pretty good. 800 rated watts with 1250 watt max and 120 volt AC 12 volt DC And 2 Horsepower! YAY HORSEPOWER!
http://cgi.ebay.com/NEW-1250-Watt-Portable-Gas-Generator-RV-Camping-Ac-Dc_W0QQitemZ180005970008QQihZ008QQcategoryZ46412QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Runs 5 hours full, 120 volt AC 12 volt DC, it only says 1000 Watts, I'm guessing that is maximum. It says it cannot be shipped to California and is only approved for 47 states.
http://cgi.ebay.com/SMALL-PORTABLE-GAS-POWERED-ELECTRICAL-GENERATOR-AC-DC_W0QQitemZ320006294652QQihZ011QQcategoryZ46412QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

If you want to look a little yourself, or get an EBay account if you don't have one, (I gave you a few with Buy It Now options)
http://search.ebay.com/ac-dc-generator_W0QQfromZR8QQfsooZ1QQfsopZ3QQsatitleZacQ2fdcQ20generatorQQsbrsrtZd
is my search page. I hope that I helped, and good luck and be careful. I was electrocuted twice :O.


Edit: Oh, did you mean a transformer?

Answer 6

yeah the rock band haha

Answer 7

Try newarkinone.com