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BrianG · 12.29.2008, 01:10 PM

Wow, 0.5A??!! That seems high IMO. A typical 2500mAh AA battery set would last about 5 hours, so I guess that seems about right. Unless that linear regulator was heatsinked outside the radio, 1.35w is too high. Doesn't sound like much, but it is.

Or, reconfigure that 5v regulator for 6v operation. Just take a couple resistors. Then the power dissipation becomes (7.7v-6v)*0.5A, or 0.85w. Still a tad high for my taste, but workable.

Or, use a hybrid setup. Run 3s (or more) with the switching BEC of your choice set to 6v along with a LVA. That'll get the efficiency back up. Then, use that 5v regulator at the output of that as a safety net. Power dissipation on the linear reg would be (6v-5v)*0.5A, or 0.5w. If you could get a low-dropout regulator instead, you could set it for 5.5v and reduce power loss to around 0.25w. A little bit of an involved setup, so I guess it depends on how badly you want to run lipos in your radio.

	(#7)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	12.29.2008, 01:10 PM Wow, 0.5A??!! That seems high IMO. A typical 2500mAh AA battery set would last about 5 hours, so I guess that seems about right. Unless that linear regulator was heatsinked outside the radio, 1.35w is too high. Doesn't sound like much, but it is. Or, reconfigure that 5v regulator for 6v operation. Just take a couple resistors. Then the power dissipation becomes (7.7v-6v)0.5A, or 0.85w. Still a tad high for my taste, but workable. Or, use a hybrid setup. Run 3s (or more) with the switching BEC of your choice set to 6v along with a LVA. That'll get the efficiency back up. Then, use that 5v regulator at the output of that as a safety net. Power dissipation on the linear reg would be (6v-5v)0.5A, or 0.5w. If you could get a low-dropout regulator instead, you could set it for 5.5v and reduce power loss to around 0.25w. A little bit of an involved setup, so I guess it depends on how badly you want to run lipos in your radio.