EzOSD Current Sensor

[dolby]

I just purchased a EzOSD and it was a snap to get it up and running however I'm having an issue with the current sensor using a 4s Lipo (16.8v).

I measure the input voltage to the current sensor at 16.8v and if I dont connect anything to the ESC (output) the OSD shows 16.8v. If I measure the voltage with nothing else connected to the output it reads 16.8v

As soon as I connect my hexacopters main power to the ESC (output) of the current sensor the voltage drops to 13 - 14v, the battery side still stays at 16.8v. The OSD shows an amp draw of 0.6 and a voltage of 13 - 14v. Why is the voltage being dropped with such little load?

I seems like the slightest bit of load will drop the voltage down. As a test I just connected (1) 30amp ESC (a spare not even connected to a rx or motor) and the voltage dropped to 15.6v while the battery was still 16.8v.

Any ideas? Would this be a bad current sensor? I purchased it from Hobbywireless last week.

[edit] Just tried a 3s Lipo and I'm seeing the same results.

[ssassen]

That's weird, there's nothing that could explain that as that would mean a huge amount of power is dissipated in the sensor, which would make it run excessively hot. Did you check the top sticky in this forum? The current sensor issue one, you could be affected if this is an older EzOSD.

[dolby]

Hi ssassen,

Thanks for your reply. Yes I did, in fact the sticker isn't even foil now its paper.

[ssassen]

Then I'm puzzled, can you draw a wiring schematic of how you've got everything hooked up?

[dolby]

Sorry it took so long, Holiday and a Birthday got in the way.

Here is my current wiring diagram. Thanks again for your help so far.

*Please note I still see a voltage drop if I just connect the EzOSD Current sensor to just 1 space ESC.

[ImmersionRC]

What's that 12V reg? Any why not use proper 5.8GHz Vtx? The Foxtech 500mW are an accident waiting to happen and excessively large. Did you know our 600mW is 1/10th the size and handles up to 6S directly?

[dolby]

I would love an ImmersionRC 600mw 5.8 tx but its never in stock when I look at all the US retailers on your website. If they ever get back in stock I may buy one.

I'm currently using this one: http://hobbywireless.com/index.php?m...roducts_id=619

But how would that fix the current sensor problem I'm having?

[ImmersionRC]

I would love a ImmersionRC 600mw 5.8 tx but its never in stock when I look at all the US retailers. But how would that fix the current sensor problem I'm having?

I'm currently using this one: http://hobbywireless.com/index.php?m...roducts_id=619

I have difficulty believing that, our US retailers orders those in batches of a few 100pcs, sometimes several times a month, they don't all go out of stock instantly.

As for your current sensor issue, I don't know. I would start a process of elimination, starting with the 12V regulator and see if removing any of these components changes anything. Also, how are you measuring the voltage? Is it displayed in the EzOSD wrong, or are you using a DVM?

[dolby]

Why would I lie about that? If you have an internet connection you can easily check your self. I needed a new transmitter two weeks ago and spent the entire week waiting for them to come back in stock, hitting every US site on your retailer list and they are still all on backorder. If you know of a US dealer that has them in stock I'll buy one right now.

Like I said above I broke down the system to just 1 ESC connected directly to the ESC port on the Current sensor and the voltage still drops. Adding more ESC's and the voltage drops even more. If you read my first post I explain how much of a drop.

Thanks for your help so far.

[ImmersionRC]

Why would I lie about that?

Don't get me wrong here, that's not what I'm saying, I know what volumes we shipped and I have a hard time believing they are all sold out that quickly. If that's the case we must have better sales than I expected

Like I said multiple times above I broke down the system to just 1 ESC connected directly to the ESC port on the Current sensor and the voltage still drops.

Where/how do you measure the voltage? That's pretty essential to figure out what is going on here. Also, are you sure you have the BATT and ESC connector on the CS wired in correctly? I.e. BATT > goes to the battery, ESC > goes to the load, your ESCs in this case. Also, apart from the voltage drop, do you also see a current being drawn? And can you measure the voltage difference between the + of BATT (input) and + of ESC (output) on the ESC, this should be no more than a few mV. Or simply measure voltage on BATT and ESC and subtract the two values, this value should be a few mV at max.