Make 5V constant DC power supply (I=500mA)

Discussion in 'The Projects Forum' started by Zeeshan Ahmed, Jan 19, 2011.

  1. Zeeshan Ahmed

    Thread Starter New Member

    Jan 19, 2011
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    hEY ALL OF YOU GUYS.....i had been given a project in which i want to make a contant 5V DC power supply....help me and give me full details or a good link about it for help...this is my first project......thnk you.,...
     
  2. wayneh

    Expert

    Sep 9, 2010
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    Consider just buying one. Any USB-type phone charger will work better than anything you build, and they can be found for very little money.
     
  3. soda

    Active Member

    Dec 7, 2008
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    Hi Zeeshan,

    Here's a diagram on a pcb you can use for your 5v supply
     
  4. wayneh

    Expert

    Sep 9, 2010
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    That'll work, and the input voltage can be from ~6-24V AC. However, the more voltage you drop across the 7805, the more heat it will produce and the bigger heat sink it will need.
     
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    That will dissipate (waste) 2 Watts as heat when the load is 500mA.

    A switching power supply dissipates fractions of a watt of heat at 500mA load.

    Plus, +5V 500mA to 2A are all over from cheap to free due to their use in phones, mp3 players, and many other consumer electronics. The designers often change the "end" for each model, so if you chop that off, you have an extremely stable power source, essentially for free.
     
  6. soda

    Active Member

    Dec 7, 2008
    174
    13
     
  7. wayneh

    Expert

    Sep 9, 2010
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    That's a valid position. However I'm personally thankful that when I come here with preconceived notions of what I want, the smart people here challenge those notions and remind me of much simpler solutions, if those exist. That's what friends are for, to challenge us before we do something silly. The OP could very easily find a circuit for himself if all he wants is a circuit. Engaging with the living, breathing people here implies a need for a bit more, the wisdom of one's friends.
     
  8. soda

    Active Member

    Dec 7, 2008
    174
    13
    Hey wayneh, thanks for the lecture you just gave me. I'LL remind myself of it the next time i post a reply.
     
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