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Starting Capacitor

  1. Apr 13, 2005 #1
    I have a 5.01 Volt, 500 mA source
    and need to power 12 Volt fan
    any suggestions
    (once the fan is in motion the power source will keep it turning)
    so would just some capacitors work to start it?
    a power boost would be more advantageous though
  2. jcsd
  3. Apr 14, 2005 #2


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    Science Advisor

    The 12V fan will likely start and run on the 5V source albeit slowly and with the possibility it would require a little push to get it started.

    Capacitors are only going to store the same voltage used to charge them. So it will only be able to go to 5V.

    You could charge 3 capacitors to each have 5V and then series them to get 15V but you would not be able to connect the capacitors and power supply together without using diodes and switches. Fairly rude goldberg-ish, and the problem is that capacitors store an incredibly small amount of useful electricity when you examine the discharge curve and how much of it you'll be able to use. So you would need large capacitors to get useful amounts of current and that costs money. It would be far easier to build a boost converter or get a 5V fan or get a 12V source in the first place.
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