Can anybody tell me what is the best way to wireup the low current sensor breakout ACS712?
I tried to connect it as it is with input wires to the large IP+ and IP-.
However I could not find a stable output. Also even when the current is varied from 1 to 4A no significant change in output voltgae is observed wven by adjusting the gain to the max.
Also with the 5V supply and common grounding on the output side
Sorry to hear that you’re having trouble with your board, are you measuring the Vo pin using a multi meter? It doesn’t matter whether you’re using the large or the small IP pads, they’re connected to each other anyway.
What are you using as a current supply for the board?
First i am testing the sensor using an electronic load and dc voltage supply. And YES, the output is connected to a multimeter.
But in my real usage the current source will be 2 x 20W PV panels in series and a data acquisition unit will be used to record the sensor output
Ok I think the issue is that you’re connecting a benchtop power supply directly up to the board yes? By adjusting the maximum current output on your supply, you aren’t changing how much current the circuit is drawing, merely allowing it to draw more current IF IT NEEDS. But the circuit itself isn’t changing and represents a constant load, therefore your output voltage isn’t going to change.
Tested it with different load settings (supply voltage fixed, load resistance varied to have different currents each time)
Hmm ok, how are you varying the circuit load? What resistor values are you using?
My settings were such that i had 1, 1.5, 2 and 2.5 A in the circuit . I also had an ammeter connected along with the current sensor , which displayed these currents.
Ok, have you calibrated it as per the instructions of the product page?
You mean by adjusting the gain and offset right? This was my attempt to calibration. I wanted to see the output of sensor for different currents. But it kept fluctuating within the same range at all current levels . (even with adjusting the gain and offset screw)
Yep, as mentioned here: “The ACS712 Low Current Sensor Breakout outputs an analog voltage that varies linearly with sensed current. To calibrate, first set the output offset to the desired level (with zero current on the sense lines, read output with a DVM). Then with a known current input (a 100mA limited supply works well for this), set the output deflection with the gain pot. Sensitivity is then calculated as (Vref - Vdeflect)/(current input).”