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How to make Regulated Power Supply

Discussion in 'Power Electronics' started by Manick9, Sep 14, 2011.

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  1. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    I need to make a power supply for a motor for my project.
    Mains Voltage is 240V AC,13A at 50Hz
    I need 24V DC for the motor and motor current rating is ard 1.7 to 2.3A.
    I am not sure what are the parts i need and what calculations i need to perform.
     
  2. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Voltage regulation

    Hi Manick9.
    Yes thats possible, in many ways, whats the project, if you dont mind me asking, as a lot of motors will happily run on rectified unregulated DC, depends on your motor application. Dave. :)
     
    Last edited: Sep 14, 2011
  3. daddles

    daddles

    443
    3
    Jun 10, 2011
    One thing to consider is buying a power supply -- they can be had for $20 to $30 or so. Here's one example.
     
  4. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    I will have to make the benchtop power supply myself like a test jig to test the motor..
    Dave i don't mind.Its a water pump motor requiring fixed DC voltage.
    If you could help me it would be gr8.
    Thanks
     
    Last edited: Sep 15, 2011
  5. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Motor control

    Hi again. How strange, forgive the phrase, not you. I was given a power supply yesterday, some one knew i was after a reasnable size transformer, on the other end of this psu was a water pump. The transformer was 4 amps rated at 12 volts output, so i was after the transformer, the attached circuit was a rectifier and smoothing capacitor, and two fuses, so if you need fixed voltage speed of the pump thats the way to go, or multi speed control can be done other ways with regulators and or resistors. Dave.
     
  6. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    Hello again.
    I don't think i can get a psu like that ere in SIngapore. Its pretty urgent.
    I will have to make the power suppy.
    I think i need to use a step down transformer,bridge rectifier,smoothing capacitor and a regulator.
    I dunno what power rating i require for the transformer.And whether i must put a fuse.how to calculate the value for smoothing capacitor.
     
  7. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Motor control

    The power for the pumps motor depends on power ratings, i know you stated a guide to power needed, but pump motors will vary in power demands, one factor is water pumped at a same as water level, or is there a gravity difference, ie pulling the water some hight. A power supply a few amps above what you need, so there is some head room in power avaliable. you can build one or buy one depends on the route you want to take, a bit more on the pumps work load would be usefull as to your psu needs. Dave.
     
  8. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    The pump operates in the range 1.7A to 2.3A. and takes in 24V. I am not sure of the power rating.The pump operates at the same lvl.
    I will have to build one as it is part of my project.
     
    Last edited: Sep 15, 2011
  9. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Motor pump control

    Ok a transformer step down for 24 volts at say 5 amps so you have some in reserve, 100 VA, volt amps should do the rectifier can be a full wave package rated at 15 amps, these come in a bolt down square package 4 tags AC in DC out a capacitor of around 10000uf 35 to 40 volts, and a fuse on the out put, i cant post a diagram as iam on my not so good phone, but if you still need a diagram, i normally put the pc on later in the day, unless another member can help and post a diagram before me. Dave.
     
  10. Manick9

    Manick9

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    Sep 14, 2011
    Thanks. A diagram would be better. No hurries upload when you are on your pc.
    I also would like to know how to ground my case.Fuse comes from the transformer output or the after rectifier?
    What Amp fuse would i need?
     
  11. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    I am not sure i bought the correct transformer.
    it is written as 0-115-230 , 30V-0-30V @12VA
    I got a 1A fuse,fuse holder,240V neon lamp,2X 0.1uF capacitors ,470uF capacitor 35V, toggle switch, 7824 voltage regulator,4 1N4001 diodes,stripboard and a power cord.
     
  12. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    pump power supply

    Hi Manick9.
    Ive drawn a diagram, but my scanner is playing up, so i will post some links to diagrams on how to build this supply. Dave. :)

    [​IMG]

    [​IMG]

    The second image is a full wave rectifier package.
     
  13. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    I do not need a regulator?I will have to go and change the transformer to 100VA and 230-24V . How does the output turn out more than 24V?I need to get a 10000uF capacitor 35V also.What is the fuse value and the watt for the 1000 ohm resistor?
    Thanks.
     
    Last edited: Sep 16, 2011
  14. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Pump psu

    Hi again. Yes 12 VA is way to small. because your power supply is not regulated, the capacitor pushes up the RMS voltage a few volts, but for motor use thats not critical as when under load the voltage will drop to about 24 volts, as for a fuse this goes on the mains 240 volts line to the transformer, a fuse of 500 milliamp to 1 amp should be ok, this type of supply is fine for a pump and motor control, the trasformers chassis or case if metal must be grounded. Dave.
     
  15. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    how do you calculate values for the capacitor?is there any formula?I need a big electrolytic capacitor of more than 10000uF right?I will be changing the transformer to 100VA.I already have 1Amp fuse with me.I thought the current coming in from the mains is 13 A isn't 1A too small? There is a 13A fuse in the power cord.What shd be the power rating of the 1k ohm resistor?
     
  16. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Motor pump

    I dont know if your misunderstanding voltage rectification, and regulation, if the pump motor is DC volts it must be a rectified power input, voltage regulation is a more accurate voltage output, not necessary for most motor pump applications, so the circuit i posted is the way to go. If your motor is DC and you try running it on AC it wont work, AC ( alternating current ) DC, ( direct current ) If the motor is AC only the transformer is needed, if its DC then the circuit above is needed. Dave.
     
  17. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    I need DC for motor. I don't think it needs to be regulated. just did not know how to do the calculations. I am a EEE student doing my 2nd yr diploma.
     
  18. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Pump motor

    the fuse is one amp on the transformers input to protect the circuit from over load, the load resistor can be half a watt 0.5 watts. the capacitor for smoothing is roughly 1000uf per amp of power, but the motor current draw will have high demands under load, so 10000uf or slightly bigger will help load conditions. Dave.
     
  19. Manick9

    Manick9

    37
    0
    Sep 14, 2011
    Thanks a lot. I will have to make it and will let you know how it goes. Just need to know how to wire up the transformer and ground the metal case.you connect the neutral to the 0 and the live to the 230V of transformer right? Earth is for grounding right

    You seem to help a lot of ppl on these forums. I saw you online and posting on other threads as well.so nice of you.
     
  20. davelectronic

    davelectronic

    1,087
    12
    Dec 13, 2010
    Pump control

    if i where you the best way forward is get some books on power supply design, and look into web articals and psu projects, they range from very simple for basic applications to high technology supplys for critical voltage and current line and load regulations, iam a hobbyist and learn through books and other known and trusted publications. Dave.
     
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