Hall Effect Current Sensor?

[Jack]

With a front dinette Fleet, there is no easy place to insert a shunt in the wires from the truck alternator. (But if there is, please let me know.)

So I'm looking for a hall effect sensor that operates on 12 V and has mV output (10 mV to say 100 mV - I can rig a voltage divider, as needed).. I've got a little multimeter panel unit that displays the solar current using a shunt and I want to switch between it and the alternator.

 

[Wandering Sagebrush]

Jack, I can’t help, but as I’d never heard of a Hall Effect Current Sensor, I called on Prof. Google to educate me.

Hopefully, someone will chip in with a source, but for those like me, here’s a YouTube clip on the topic

‪What is Hall Effect and How Hall Effect Sensors Work https://youtu.be/wpAA3qeOYiI via @YouTube‬

 

[PaulT]

Search for "hall effect ammeter" and you should find what you want..

Paul

 

[Jack]

I'm just looking for the sensor - I have a small panel mounted meter mounted next to my battery monitor on the front of the kitchen panel. I was hoping someone had come across a 12 V powered through-hole sensor.

Searching for "hall effect ammeter" (instead of sensor) did turn up a Bayite meter with a sensor that should work with my meter.

The YouTube video gives a good explanation of the hall effect. Of the many applications, one not listed was rocket engines. A number of satellites (and some space probes) have hall effect thrusters.You take a heave atom, typically Xenon, strip an electron off it to create a large positive ion and use a magnetic field to shoot the ions out the back of a can to create thrust in the opposite direction..

 

[BillTheHiker]

Never heard about this. Seems like I could use an ammeter to determine amps my compressor fridge is actually drawing. Purpose is to make projections for how long battery can power it and determine if I need more solar.
Found a $19 one on Amazon:
https://www.amazon.com/bayite-Digital-Current-Voltage-Transducer/dp/B01DDQM5PK

How accurate would such device be compared to one that uses a shunt? Would it be good enough for my stated purpose?

 

[PaulT]

If would likely be of sufficient accuracy to measure instantaneous alternator current. The issue is that the alternator current will vary depending on engine speed, state of charge of starter battery, state of charge of the camper battery, etc. Additionally, with varying current, you would need to track current over time to compute energy into & out of the camper battery.

You really need a battery monitor to sum all the currents into & out of the camper battery to give you a better estimate of SOC.

Paul

 

[BillTheHiker]

Thanks Paul,

I am not really interested in what is going on at the alternator end. I just want to know how much my fridge is drawing so I can estimate how many days it will go without driving the truck and on days with no sun. So my plan is to hook up this device when the camper is in the garage[no sun] and see what it reads with only the fridge running. It appears I would pass the positive battery cable through the loop hole in the device -is that right?

 

[ClimberRob]

Bill: in my opinion, you're better off just installing a shunt-based monitor next to the battery. The shunt doesn't need a lot of space, and it's reasonably accurate. If you want to measure just the fridge, shut off everything except for the fridge and run it for 24 hours under your desired conditions (heat, ventilation, etc.).

 

[ClimberRob]

With a front dinette Fleet, there is no easy place to insert a shunt in the wires from the truck alternator. (But if there is, please let me know.)

So I'm looking for a hall effect sensor that operates on 12 V and has mV output (10 mV to say 100 mV - I can rig a voltage divider, as needed).. I've got a little multimeter panel unit that displays the solar current using a shunt and I want to switch between it and the alternator.

You don't have room to install the shunt directly next to, or on, the battery?

 

[PaulT]

I misunderstood your need. In that case, the no cost way is to use the mfg published spec for energy use. Or buy a clamp on DC ammeter and clamp it around the fridge power lead to make your measurement.

Paul

 

[Jack]

I was only interested in alternator charging - I've got a battery monitor and a Bluetooth MPPT to get the other numbers.

Here's the threadd on answering that question:
http://www.wanderthewest.com/forum/topic/18925-how-much-juice-is-your-alternator-getting-to-the-camper-batteries/