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BrianG · 08.15.2009, 03:03 PM

zero: this is the failsafe thing I was building: http://rc-monster.com/forum/showthread.php?t=22819

And adding a regulator works when the voltage is high, but anywhere near LVC, the drop-out value (usually 1-1.5v, even with LDO types) limits its usefulness. When the 2s LiFe pack is peaked at 7.2v, a 1v drop-out is fine because you still get 6.2v. As you can see though, a drop-out even as low as 1v will limit the output much below that. At just 3v/cell, you can only get 5v out. Linear regulators are kind of limited when it comes to current and differential voltage. Neither can be too high or power dissipation is high as well. Switching regulators work, but you need to find one that is both a "buck" (which is what all our UBECs are) and "boost" depending on what voltage it is being fed.

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BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	08.15.2009, 03:03 PM zero: this is the failsafe thing I was building: http://rc-monster.com/forum/showthread.php?t=22819 And adding a regulator works when the voltage is high, but anywhere near LVC, the drop-out value (usually 1-1.5v, even with LDO types) limits its usefulness. When the 2s LiFe pack is peaked at 7.2v, a 1v drop-out is fine because you still get 6.2v. As you can see though, a drop-out even as low as 1v will limit the output much below that. At just 3v/cell, you can only get 5v out. Linear regulators are kind of limited when it comes to current and differential voltage. Neither can be too high or power dissipation is high as well. Switching regulators work, but you need to find one that is both a "buck" (which is what all our UBECs are) and "boost" depending on what voltage it is being fed.