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Buy Equipments to start up my lab

  1. Sep 16, 2011 #1
    Hello all

    I want to buy few equipment. I want to set up my lab and start developing AC/DC converters. I have few years of experience but as I have worked in large company I dont know which is the cheap substitute for following equipment.

    I would like to have

    1) A power Supply- I have used Agilent power supply, I want a cheap substitute for this one. My requirement, should have 1.5 KVA rating, upto 300 V AC, variable frequency, 45-65 Hz. Output current 5A (Max). If it is giving AC + DC then its better but its not a requirement.

    2) A power analyzer- Have used Yokogawa. I want a analyzer which has a resolution of 250mA or less and 0-300 V for voltage. It should measure, voltage, current, power, power factor, THD, current peak. Must be atleast 2 channels.

    3) A good Oscilloscope- I will be using mostly analog devices, but might use digital device. For analog circuit maximum frequency on circuit will be 250 kHz and for digital 5 MHz. Which Scope will be good. I am using LeCroy scope.

    Can anyone tell me a cheap substitute for this equipment. I tried searching internet but it seems that I am not able to find a company. Any suggestions or any questions are welcome. Will be waiting for replies.

    Thanking you.

  2. jcsd
  3. Sep 17, 2011 #2
    What you are doing is not going to be cheap.
    Search the WWW for what you want. EBay?.
    Go to ham radio sales.
    Sometimes colleges or businesses sell their surplus equipment.
    Will your present employer sell you some of their surplus or broken equipment? Tell your company you want to make some simple experiments so you can better understand what you are doing. Don't tell them that you intend to compete with them.

    Depending on what is available you should probably start with:
    For 50/60 hertz would forget 50 hertz and start with 60 hertz only.
    Get a variable transformer and isolation transformer + circuit breaker and on/off switch. (60 hertz problem is solved)
    For 45 to 60 hertz would buy a 60 hertz motor and a 50 or 60 hertz generator. Couple the motor to the generator with pulleys and belts. Change the diameter of pulleys to change the frequency.
    Above is the direction that I would start out. If a solid state unit could be found that is reasonably priced, that would be OK.

    Do not purchase a power analyzer. Use oscilloscope and do calculations.

    Purchase digital oscilloscope. An analog scope will probably not give good results.

    More important than any of the above is a stock of components. If you need a 10 ohm resistor and have to order it, it will take a minimum of 2 or 3 days. A few times like this and a month will have passed. GET A GOOD STOCK OF COMPONENTS.

    Also there are tools, soldering iron, screwdrivers, wrenches, metal working tools to cut holes is chassis.

    Also you should have other test equipment. Voltmeters, ammeters, some sort of load (Light bulbs are nice, they light up when everything is working), some sort of current transformer so can see current, clip leads....... computer system to write reports, letters......

    Software: DipTrace is good program to design small printed circuit boards, should have Microsoft Word and Microsoft Excel or equivalent

    Good Luck
  4. Sep 17, 2011 #3
    This doesn't sound like a scratch in the bucket for power supply design. Some other items that are pretty much a neccesity are:

    One or more current probes
    One or more programmable loads
    A spectrum analyzer and LISN
    A temperature chamber
    Plenty of thermocouples and a way to monitor them

    And, if you're really serious:
    A means of air flow control (for cooling studies)
    A network analyzer to ensure that the tuning responds properly
    An HF antenna with amp to check for low band radiation

    Off line power supply design is a seriously capital intensive business, that is, if you want to make products that are reliable, meet safety agency approval, and CE/FCC approval. After all that, most of these products are shipping at cost + less than 10% from Taiwan and China.
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