Mastech DC power supplies

Discussion in 'Power Electronics' started by vpoko, Apr 19, 2012.

  1. vpoko

    Thread Starter Member

    Jan 5, 2012
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    Does anyone have experience with Mastech DC power supplies? I'm looking at two models:

    1. The HY3005D-3. Linear, 30V, 5A, three outputs (one fixed @ 5V, 3A, the other two adjustable and usable independently or together in series or parallel) http://www.mastechpowersupply.com/d...-30v-5a-hy3005d-3-triple-outputs/prod_10.html
    2. The HY5005-2. Switch mode, 50V, 5A, two outputs (adjustable, usable independently or together in series or parallel). http://www.mastechpowersupply.com/d...y-30v-5a-hy3005f-3-triple-outputs/prod_9.html
    First, does anyone have experience with the brand and are they reliable? They're far less expensive than similar spec'd supplies from other manufacturers. Second, will a switch mode supply give me clean enough power to directly plug into microcontroller/digital logic projects, or will I need to use an additional linear regulator (7805 or similar)? This will be my main use for the supply, and perhaps I may use it to power a few motors one day. Having a hard time deciding whether my application calls for linear or if I should go with the switch mode. Any other power-related recommendations? Thanks!
     
  2. #12

    Expert

    Nov 30, 2010
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    It's a rare day when I need more than 30 volts. I'd go for the 30V linear supply because it should be cheaper and has plenty of volts for my needs.
     
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  3. BSomer

    Member

    Dec 28, 2011
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    106
    I have one that is similar to the linear you pointed to. The difference is that the displays are analog. I haven't had any issues with it and it was used when I got it. It was purchased from the college I went to after they upgraded all the lab equipment. I agree with #12 that the 30 volt model will be a fine choice. You already said that you plan on using it mostly for microcontrollers and the sort so it would be unlikely that you will need more voltage.
     
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  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    I just bought 2 x Protek 6003L (0-60VDC 3A)power supplies.. They are great..
    For $230 USD you can't beat them..

    For all the power supplies make sure you follow the wattage rating too.. Just because it says 0-30V, 3A doesn't necessarily mean it will do 3A @ 30V
     
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  5. #12

    Expert

    Nov 30, 2010
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    That sounds like some kind of trickery.
     
  6. saturation

    Member

    Dec 21, 2008
    22
    4
    I have one of Matechs: the 3030D. Your link is a best site to buy a Mastech brand supply because there are many other sites that sell similar looking units or identical brands, but they may not be made the same. For over 10 years, various users at the RCgroups forum have bought from Sean, the guy at Mastech, and have been happy with their purchases. Its what convinced me to get one 2 years ago. Several owners have posted tear downs and performance reviews on eevblog.com forum.

    That said, all is not peachy with the 3030D. The best is the published specs are accurate when pulling rated load, in this case 32V, 3A. However, the voltmeter sense leads are improperly placed and it has a fairly high internal resistance as a voltage source, so as loads increases, the voltmeter reading is increasingly off, you'll need a DMM across the load to monitor it properly. The current reading is accurate. Its easy to mod to correct the problem, but I haven't had the time.

    The LED models are better if you work indoors, its easier to see at any angle compared to backlit LCD, this one is a particular popular:

    http://www.mastechpowersupply.com/d...triple-outputs-30-v-5a-new-model/prod_81.html

    There are some reviews of look alike PSU on youtube, and some are incredibly awful: noisy, ripply, turn on overshoot, etc., so beware. For example, this clone of the 3030D:

    http://www.youtube.com/watch?v=0tI0A9nwxaU
     
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  7. vpoko

    Thread Starter Member

    Jan 5, 2012
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    Great info, thanks! I noticed on Amazon that there are units with different brand names that look identical and use the same model numbers as the Mastech; I figured that was par for course with Chinese-made electronics, but it's good to know that they're not all the same and I'll definitely be sure to buy mine from the site I linked. Also good call about LED's being easier to read at an angle than LCD's, I was leaning toward the LCD version but will be going with the LED one instead.
     
  8. saturation

    Member

    Dec 21, 2008
    22
    4
    Glad it helps. Note, if you buy from Sean email him too, because sometimes the stock status may not be accurate.

    S&H can be costly, given the weight of the linear supplies. Expect $25-35 for shipping atop the price.

    If you are experienced with repairing or restoring used electronics, better option are eBay used Agilent 36xx series linear supplies, which goes for under $200, delivered. They are either dual or single supplies in various power output capacities. Other great options are vintage analog scale Kikusui, Kenwood, [Japanese made] Sorensen or Power Designs [ USA made] supplies. They can be had far cheaper and are far better made and spec'd, but you have to known how to spot a good deal, many old supplies are best if well used compared to one that has been unused, due the risk of electrolytic capacitor dielectric decay.

    Finally, linear beats SMPS for most lab uses, because of far less than 1/10th less noise, and that's comparing linear versus SMPS from Agilent's line. With the Chinese brands, you never know.

    Enjoy and good hunting.
     
    Last edited: Apr 20, 2012
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  9. vpoko

    Thread Starter Member

    Jan 5, 2012
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    Thanks again! I'm a total newbie so I'm going to go the new item route so that it hopefully works right out of the box.
     
  10. panic mode

    Senior Member

    Oct 10, 2011
    1,320
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    @vpoko,

    just out of curiosity, where did you see 0-50V? i followed your links and both lead to power supplies that are 0-30V
     
  11. vpoko

    Thread Starter Member

    Jan 5, 2012
    258
    47
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