Looking on Aliex & eBai , all the Hall current sensor modules I can find are bi-directional.(0A = VCC/2)

I am looking for uni directional so I can get better resolution for DC current.
It should have AU suffix but so far I can't find

Thanks

 

Have you looked here?

https://www.allegromicro.com/en/products/sense/current-sensor-ics

 

Looking on Aliex & eBai , all the Hall current sensor modules I can find are bi-directional.(0A = VCC/2)

I am looking for uni directional so I can get better resolution for DC current.
It should have AU suffix but so far I can't find

Thanks

@tonigau
A Web search for "Hall sensor Arduino module uni directional" will get you a lot of choices and info.

 

Thanks for the suggestions, but I cant find a module with uni-dir chip on.

I will get the ACS712 modules & replace the 712 with a 713 chip, this will work for me.
or the ACS758LCB-050U
not sure why the market is dominated by the bi-dir version, is everyone measuring AC or charge/discharge circuits ?.


thanks

 

Thanks for the suggestions, but I cant find a module with uni-dir chip on.

I will get the ACS712 modules & replace the 712 with a 713 chip, this will work for me.
or the ACS758LCB-050U
not sure why the market is dominated by the bi-dir version, is everyone measuring AC or charge/discharge circuits ?.


thanks

The ACS712 will measure unidirectional current (DC) as well as it will measure bi-directional current (AC). The only downside, if we even wish to call it a downside, is the output is offset at 2.5 volts when using a 5.0 volt supply. The ACS712 has a few versions it comes in which are 5 Amp, 20 Amp and 30 Amp with output sensitivities of 185 mV/Amp, 100 mV/Amp and 66 mV/Amp respectively.

The ACS712 is an older version of Allegro's current sensor chips. Newer chips like the ACS724 current sensor chip do offer some DC versions but the ACS712 can be used in both bi-directional and uni-directional applications. Also don't take bi-directional to always mean an AC current. Think about a current meter placed on a battery. Driving a load the battery has a current flow in one direction but when I charge the battery the current flows in the opposite direction. So if I monitor the current into and out of the battery it has a bi-directional current flow which is actually DC isn't it? The term bi-directional does not always imply AC. Sometimes, using automotive applications as an example, we want to know if a battery is charging or discharging.

Ron.

 

The sensitivity is much better when measuring DC (single direction current) with the ACS713 & better matches my ACD input range compared to the ACS 712 which I can only use significant limited number of ADC values.

ACS713ELCTR-20A-T 185 mA/V, ACS712ELCTR-20A-T 100 mA/V



My application has unidirectional current, the ADC I am using has 5V reference so the 713 is better suited as indicated in above graphic (from ACS71x datasheets).

I understand the 712 & 713 are "Not for new designs" due to Allegros end of life status but the availability of newer chip'd modules in the maker market would likely be delayed for some time yet.
Maker market suppliers have a habit of not moving away from outdated parts (like PIC16F877/A)

hi Ron, yes the current would look like DC if one had a meter measuring...
Not trying to be too pedantic(I cant help it) but discharge/charge current of a battery would still be defined as Alternating Current(periodically reverses direction), Just the period time is usually high & duty asymmetrical . This is most evident looking at a data-log graph of the solar charged/load discharged battery current .
---------------------------
Anyway, my gripe is: why the Uni-directional ACS713 module boards are almost non existent in the maker module market ( from my searching so far).
Tonigau

 

You may want to consider the ACS712 is heading to being obsolete. From our friends at Allegro:

Not for New Design
These parts are in production but have been determined to be
NOT FOR NEW DESIGN. This classification indicates that sale of
this device is currently restricted to existing customer applications.
The device should not be purchased for new design applications
because obsolescence in the near future is probable. Samples are no
longer available.
Date of status change: June 5, 2017

Note the status change date is a few years ago. Eventually existing stock will be depleted.

Recommended Substitutions:
For existing customer transition, and for new customers or new applications,
use ACS723.

The ACS713 data sheet from Allegro has the same header with the same suggested replacement. Both the ACS712 and ACS713 are on their way out. This really matters not for a one time design use but for multiple use long term they are telling us it is at the end of its life cycle.

Ron

 

|-o-|
If the module has a 713 I will buy it, if it has a 723 I will buy it.

They are both pin compatible so I don't see any real issues except the difference in sensitivity.
My board has a calibrate function in firmware.

 

If you want a hack, get a bidirectional one and add a magnet to it to offset the reading to zero.

 

Hi

You can also remove the output offset using an opamp.

eT