Tuesday, May 2, 2017

Current / Voltage Module - Voltage Divider

Cheap Power Module w/Current Sensor

 From Banggood

(Weight of this module as-received is ~20.79g, while the module board only is 4.01g.)


Voltage Sensor - Voltage Divider

BEWARE!!!  This module voltage sensor does not output 3.3v which can burn out a flight controller if connected directly.

Voltage output of this module:
Input (Battery) Voltage Module Output Voltage
(3S) 12.25 6.27
(4S) 16.62 8.51

A simple voltage divider circuit can be added to the module output to get a 0-3.3v range for use on flight controllers.

Voltage Divider Calculator HERE

The suggested values to use are:

R1 R2
Module (3S) 6.27 1k 1k
Module (4S) 8.51 3.3k 2k
(3S) 12.6 10k 3.3k
(4S) 16.8 10k 2.2k

Remember to perform voltage sensor calibration on the flight controller.

Current Sensor

The current sensor on this power module seems to be okay for use on 0-3.3v flight controller.

Measured Current Module Reading Calibration(amp/volt)
7.82 0.400 19.550
8.43 0.438 19.247
12.69 0.540 23.500
13.45 0.590 22.797

This may be a 75A current sensor?