Imported from GitHub: ThunderFly-aerospace/TFSBEC01 · commit fdcb78b · license GPL-3.0

Description

High efficient switching power supply for UAV actuators.

README

TFSBEC01 - High efficient power supply with measuring circuit for UAV

Many devices in unmanned vehicles require a quality power supply, and it is very useful to know the actual and real consumption of these components. Our TFSBEC module is designed to provide power to servos, autopilot (flight controller), and other medium-power drone accessories. In case the user needs more current or two independent sources on his drone, for example, a separate source for avionics and power-consuming elements (actuators), it is possible to chain these modules.

Parameters

Parameter	Value	Note
Regulator technology	Switched step-down	LMR14050
Input voltage	6 - 40 V	Equivalent of 2S to 9S li-pol accumulators
Output voltage	5.4 V, 5 A	based form the PX4 standard, can be adjusted
Regulated connector	Molex Click-n-mat 6p, JST-GH 6p	Connectors are parallel
In/Out connector	XT30	max current 15 A
Current measurement range	0 - 50 A
Volts per Amper	39.6 mV/A	From component datasheet
Current measurement Volts offset	330 mV	From component datasheet
Voltage measurement range	0 - 40 V	Depend on target ADC max input ( max. 3.95 V )
Voltage measurement divider	10.13	From schematic
Size	approx. 46 x 30 mm	PCB only
Weight		PCB only
Compatibility	Pixhawk-based drones	As a quality source, it can be operated on any drone

PX4 Params

These constants are nominal values taken from the datasheet:

• A = BAT1_A_PER_V = 25.2525
• B = BAT_V_OFFS_CURR = 0.33
• BAT1_V_DIV = 10.13

QGC build-in measurement can be used to estimate parameters more precisely for the specific piece. The PX4 estimation of current is calculated from the ADC raw voltage by the following formula:

For the computation of BAT_V_OFFS_CURR, multiple current measurements are usually needed, because there are significant peaks due to powering of electronics with a low current consumption.