Twosky2000

Members
  • Content Count

    3
  • Joined

  • Last visited


Reputation Activity

  1. Like
    Twosky2000 reacted to zador.blood.stained in Voltage Regulator 7805   
    For the 7805 dropout voltage lower than 3V is not recommended and lower than 2V may not work reliably, so the input voltage should be at least 8V.
  2. Like
    Twosky2000 reacted to zador.blood.stained in Voltage Regulator 7805   
    Well, 7805 is a linear regulator, so it will generate a lot of heat at this voltage difference and current.
    Tips? Use a switching (buck) converter.
  3. Like
    Twosky2000 reacted to pzw in Voltage Regulator 7805   
    Agree with zador. What you can try to do (if possible) is lower the voltage to 8-9V, instead of 12V. That will remove 1W of heat from the 7805. Also install a heatsink on the regulator, and do not forget to add a electrolytic capacitor of 220uF - 1000uF at the output of the regulator to take care of the current surges a SBC produces at times.
    Depending on the exact type of the 7805 you might run into the max. current handling capacity. The most common TO220 version is standard 1A max... There are 78M05 units, but those will require a heatsink for the much higher current.
    All in all is a 7805 a poor choice for your application. I would recommend looking at a switching regulator of i.e. Recom. Do not forget the additional capacitance on the output though...
  4. Like
    Twosky2000 reacted to zador.blood.stained in Voltage Regulator 7805   
    For the 78xx electrolytic cap should be on input and ceramic cap should be on output (as close to the regulator as possible). For all types of regulators looking at the datasheet is recommended before trying to apply a common sense - some require a ceramic cap on the output while others require electrolytic one for the stability.
    In any case 78xx or any kind of linear regulator should not be used here - it will consume more power than the board itself at this voltage difference.
  5. Like
    Twosky2000 reacted to Igor in Voltage Regulator 7805   
    LM2596 should be right for the job - it can cope with such loads and they are dirt cheap.
     
    https://www.aliexpress.com/wholesale?SearchText=LM2596