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Suggestions for a bench top power supply and frequency generator? — Parallax Forums

Suggestions for a bench top power supply and frequency generator?

vanmunchvanmunch Posts: 568
edited 2014-02-04 07:25 in General Discussion
Hey everyone, I’ve been thinking about buying a bench top power supply and possibly a frequency generator and I was wondering what you would recommend in the ~$100 price range. Would it be possible to get one with digital readouts and 2-3 outputs or is that just crazy? :)

Thanks!

Dave

Comments

  • TCTC Posts: 1,019
    edited 2014-02-02 14:46
    For a bench top power supply, I am using a PC power supply. It might not be the cleanest voltage, but it offers me the 3 voltages I care about. And right now I don't have a need for clean voltages, just right voltages with all the current I could need.
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-02-02 14:49
    I have this one and have been happy with it so far. I have had it for a little over a year.
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-02-02 15:23
    There are several bench power supplies that fall into that price range and aren't too bad. Just be sure to get one with current limiting. I don't think you find a decent one with multiple outputs though. I have a couple of HP E3610A power supplies, so I don't keep up with the latest stuff, but I think Korad got most of their initial problems with the KA3005P sorted out.

    A PC power supply can deliver an almost ridiculous amount of current if you short it out. Just about guaranteed to turn your project into a smoking pile of melted wires and plastic if you make a boo-boo.
  • Mark_TMark_T Posts: 1,981
    edited 2014-02-02 17:15
    Firstly these are my strong requirements - you may differ, but I'd hate not having them:

    Physical pots to dial up current limit and voltage - you can power it up in exactly the state
    it was in when you last used it.

    Coarse and Fine pots for both current and voltage, really really useful.

    Analog meters. Nothing else shows you the current and voltage kicks as well, and by
    analog I'm not ruling out a LCD bargraph style, so long as its quick to respond to
    transients (this is most important for current, but useful for voltage). I'd like
    digital meters too of course, but if I need an accurate voltage I get the multimeter out
    and measure it at the end of the leads where it matters.

    Real analog meters let you see the voltage in the circuit after you switch off the supply!
    Great for battery charging.

    A current-limit LED with pulse-stretcher so you can see even momentary current limit
    events...

    Big chunky power switch at the front so you can kill the power QUICK!

    Floating outputs with a removable link to connect one of the +ve and -ve terminals
    to earth. Then you can use it as +ve or -ve rail supply, or floating.

    3A minimum.

    Mine's an Instek PS-3030 (I'd like more volts than 30 though).
  • ratronicratronic Posts: 1,451
    edited 2014-02-02 17:49
    I have a Mastek dual output 0-50v 0-5amp that the supplies can be switched in series, parallel, and independent. It only has course adjustment pots but each supply can be operated in constant voltage or constant current mode.

    I think it was put together somewhere in Asia but it serve's my purpose. Especially since I ended up getting it for free via Ebay. Only had to replace a broken pot.
  • TubularTubular Posts: 4,703
    edited 2014-02-02 18:12
    We bought a bunch of Manson SSP-7080s a couple of years ago and have been happy with them. I like the 4 digit displays that read in MilliAmps, Millivolts directly.

    They are flexible in that they can be Master/Slave (for dual tracking operation, or higher current, higher voltage, etc)
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-02-03 05:13
    Depends on whether you desire to buy new, or to buy used. There are an awful lot of bench power supplies and frequency generators sitting around unused. EBay might offer you some very attractive bargains. And a regional HAM radio swap meet might even do far better.

    It is just as much about where you buy as about what you buy.
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-02-03 08:03
    You might want to do some reading on the EEVblog Forums. They have one dedicated to "Test Equipment" and one for "Other Equipment & Products". There are some very knowledgeable people there. They love to tear into equipment and expose every flaw. They also have a lot of respect for well designed and manufactured products, no matter how old.
    Test Equipment

    Test Equipment reviews, teardowns, discussion, questions etc. This is the biggest T&M forum on the net, so your product has likely already been discussed, please use the Search function in the menu above first!
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-02-03 08:16
    I am wondering what you need the frequency generator for.

    Do you already have a scope?
    Is it going to be for analog sine wave as well as digital? Are you wanting to go way up into the RF range or do you want an audio generator?

    You can pretty well generate a digital signal up to 80 Mhz with the Propeller itself.
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-02-03 10:53
    I just saw where Digilent is offering their Analog Discovery Kit at the $99 student price for those registered in the edX "UT.6.01x Embedded Systems - Shape the World" class (it looks like registration is still open and it's free if you just want to audit). This is a very good deal, it is well worth that price. It includes a 2 channel 5 MHz AWG
    Arbitrary Waveform Generator
    • Two channels; 14-bit converters; 100 MSPS real-time sample rate
    • Single-ended waveforms with offset control and up to ±5 V amplitude
    • 5MHz analog bandwidth and up to 16k samples/channel
    • Easily defined standard waveforms (sine, triangle, sawtooth, etc.)
    • Easily defined sweeps, envelopes, AM and FM modulation
    • User-defined arbitrary waveforms can be defined using standard tools (e.g. Excel)
    • Cross-triggering between Analog input channels, Logic Analyzer, Pattern Generator or external trigger
  • Too_Many_ToolsToo_Many_Tools Posts: 765
    edited 2014-02-03 18:20
    RDL2004 wrote: »
    You might want to do some reading on the EEVblog Forums. They have one dedicated to "Test Equipment" and one for "Other Equipment & Products". There are some very knowledgeable people there. They love to tear into equipment and expose every flaw. They also have a lot of respect for well designed and manufactured products, no matter how old.

    I love that site...and yes..they do a great job of ripping the stuff apart.

    And there is a lot of truth in that the old stuff is the best stuff...engineering quality into anything cost money...money most companies do not want to spend today.

    The downside is that the older equipment is old...and like all of us, age causes things to fail and many times that are no replacements.
  • Too_Many_ToolsToo_Many_Tools Posts: 765
    edited 2014-02-03 18:24
    Loopy Byteloose wrote: »
    Depends on whether you desire to buy new, or to buy used. There are an awful lot of bench power supplies and frequency generators sitting around unused. EBay might offer you some very attractive bargains. And a regional HAM radio swap meet might even do far better.

    It is just as much about where you buy as about what you buy.

    Ham fests, swap fests are great places to buy...if you can test it before you buy it.

    They are also great places to sell your junk to the next sucker...buyer be very aware.

    I have many, many stories of junk being pushed at ham fests.

    One can use Ebay's location feature to look for nearby sellers of test electronics....there by avoiding shipping and be able to test before commiting the cash.
  • vanmunchvanmunch Posts: 568
    edited 2014-02-04 07:25
    Hey everyone, thanks for the info! I might actually break down and buy one. :)

    Dave
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