Rx6x Monitor 1s lipo in Voltage Booster

DESCRIPTION

Single cell lipos (1S) are a convenient power source because they are cheap, available in many sizes, and do not require balancing. Lipos are charged to 4.2v and used down to 3.0v. This is often not enough volts to power a motor. Voltage boosters can increase the voltage but these don't usually have low voltage protection. Lipos are damaged if their voltage falls too low.

This feature allows the Rx to be powered with the boosted voltage and monitor the voltage of the lipo with a separate input. The Rx will cut power to the motor when the lipo voltage falls to 3v.

This feature is not intended to be used when powering the Rx direct from 1 lipo.

CONNECTIONS

The Rx6x input can only measure up to 1.1v and the lipo can be as high as 4.2v when fully charged. So two external resistors are required to divide the lipo voltage by 4.

Suitable resistor combinations are 1k+3k, 1k1+3k3, 1k2+3k6, 1k3+3k9. This 1+3=4 ratio is important. Resistors with 1% accuracy are recommended but not essential. Any size/watts can be used.

ASSUMPTION

This feature and the wiring diagram assumes that the negative path is 'straight through' the voltage booster. Put another way, negative on the input of the voltage booster must be 'common' with negative of its output. This is usually easy to confirm by visual inspection.

RX SETUP

Rx60: Enable P1 for the 'boost' option (3,1,5).

Rx61: Enable P2 for the 'boost' option (3,2,5).