Mounting Turnigy Watt Meter

[tkollen]

After having read this thread I decided to do the Jeremy-mod and I bought a Turnigy meter a few weeks ago. It looks like they have changed their design. There are no more potentiometers for calibration. An unused 3-pin connector is visible on the piggyback board. Does anyone know if this version can be calibrated and if the 3-pin connector and the IN-/IN+ lugs can be useful for the mod?

 

[izeman]

i have not found a way to calibrate them. but on the other hand i didn't investigate much time.
if you use thick enough cables, and to a good enough soldering job, and cables are not too long, then offset should be neglectable. my mod is in the lower percentage offset.

 

[amberwolf]

An unused 3-pin connector is visible on the piggyback board.

Do you have a picture of that connector? (your picture only shows the 2-pin and a six pin)

Does anyone know if this version can be calibrated and if the 3-pin connector and the IN-/IN+ lugs can be useful for the mod?

I suspect the in-/in+ are alternate connector pins for power, but you'd have to trace them to find out.

I expect the 6-pin connector is for programming the MCU, but again you'd have to trace it out to see.

 

[tkollen]

The 3-pin male connector is on the right of the pcb. I did contact HobbyKing with the same question and they cleared it up. It is for an alternative power source. So my only question that remains is about calibration.

 

[amberwolf]

Ah, I misunderstood, since the TWM manual that came with mine explains what that side 3-pin is for. I assumed you meant "unused" as in "nothing installed to the PCB pads".

 

[merv]

doesnt work, waste of time

 

[Jeremy Harris]

doesnt work, waste of time

You're wrong. I have three modded like this, all work fine. Several others have done the same and seem happy.

What's your problem, maybe we can help you fix it?

 

[MAGICPIE3FOCUSPOWER]

Finally I had some good feelings to do this mod.
I can say it's cheap mod and works perfect!

Also I had to remove Turnigy brand logo, I like clean look.

I will make some picrures.

Thanks Jeremy! 8)

 

[merv]

I cant remember but i think it was stuck on 90amps or something il have another look at it, iv got a 50amp 75mv shunt could i use this shunt? Im guessing now because watever the turnigy shunt is calibrated for the original shunt.
Its covered in solder n watelse now originaly it was clean n neat but after an hour of solder n wires its a mess.
Is there different models of the turnigy watt meter? Mine was purchased 6 months ago from hobbyling no writing on circuit board

 

[Jeremy Harris]

I cant remember but i think it was stuck on 90amps or something il have another look at it, iv got a 50amp 75mv shunt could i use this shunt? Im guessing now because watever the turnigy shunt is calibrated for the original shunt.
Its covered in solder n watelse now originaly it was clean n neat but after an hour of solder n wires its a mess.
Is there different models of the turnigy watt meter? Mine was purchased 6 months ago from hobbyling no writing on circuit board

If it was stuck on 90A then that sounds like a wiring problem to me. The original shunt is a 0.001 ohm, 1% tolerance, 3 watt rated surface mount resistor. The meter should work OK with any 0.001 ohm shunt resistor, but may need calibrating after the mod to get the readings spot-on.

I believe the newer models may not have the calibration pots, based on the observations of others, but I'm not sure when this change took place.

 

[dilkes]

I am about to do the remote shunt mod on my Turnigy Wattmeter. My question before I start:

Is standard telephone wire sufficient for the 3-wire connection from the shunt up to the display? If not, what would be a better choice for a small gauge wire?

Many thanks

 

[d8veh]

I am about to do the remote shunt mod on my Turnigy Wattmeter. My question before I start:

Is standard telephone wire sufficient for the 3-wire connection from the shunt up to the display? If not, what would be a better choice for a small gauge wire?

Many thanks

Any wire with three or more conductors is OK. I've used telephone wire, but it's not the best choice because the single strand conductors can break due to fatigue, so, if you do use it, make sure that all the wires are tied down so that they can't move or vibrate.

 

[sacko]

Saw this thread a while ago and finally got around to doing it. I should have taken note when someone in this thread mentioned the design of the Turnigy Watt meters have designed as there arent any pots to adjust the thread amp readings.

I hooked mine up to my charger, these are the results;

Doh..

 

[amberwolf]

There may well be issues with the TWM's calibration now, but you should note that at least some (and I expect many) RC chargers don't accurately report current (or voltage!). If you poke around my Venom charger thread and RC LiPo repair thread there's some info there about how inaccurate the readings were, even compared to a TWM (whcih itself is inaccurate).

 

[powerlord]

Hi Guys - I'm gonna stick one of my spare wattmeters not used on the bike in my motorhome.

thing is - shared earths or van body means it's difficult to know where I can actually stick it.

There are two 12v batteries (one each side of van) wired in parallel.

I've tried the 3 wire method on the earth out of one of the batteries, but then, of course I'm only reading half the current draw effectively (assuming each battery is balanced and same resistance under load).

I could fart around trying to unearth batteries and connect them through cables only, etc but I wondered if passing +ve through the turnigy instead of -ve in the 3 wire layout would work ?

ie:

source+ : battery
source-: no connection

load+ : all van load +
load-: thin earth wire

would that work ?

 

[Samd]

Happy to 3d print some snapin handlebar mounts if people are keen?

 

[dnmun]

Hi Guys - I'm gonna stick one of my spare wattmeters not used on the bike in my motorhome.

thing is - shared earths or van body means it's difficult to know where I can actually stick it.

There are two 12v batteries (one each side of van) wired in parallel.

I've tried the 3 wire method on the earth out of one of the batteries, but then, of course I'm only reading half the current draw effectively (assuming each battery is balanced and same resistance under load).

I could fart around trying to unearth batteries and connect them through cables only, etc but I wondered if passing +ve through the turnigy instead of -ve in the 3 wire layout would work ?

ie:

source+ : battery
source-: no connection

load+ : all van load +
load-: thin earth wire

would that work ?

no that won't work. the current has to flow through the negative wires in order to measure the current. so you have to put the wattmeter in the ground wire of the battery. the positive lead can go to the battery or any other 12V source. you only have to connect one end of the red wire. unless you send current through it to charge the battery and then it has to be between the alternator and the battery positive terminal.

 

[juliusmagnificus]

Hi all, I did the mod and it works perfect.

 

[heathyoung]

You can actually buy these (rebranded) designed for an external shunt so someone must make them like this already...

http://www.jaycar.com.au/productView.asp?ID=MS6172

 

[dnmun]

Hi all, I did the mod and it works perfect.

did you install that rocker switch on the end also? neat idea.

 

[juliusmagnificus]

did you install that rocker switch on the end also? neat idea.

Yes, like this one :

 

[MAGICPIE3FOCUSPOWER]

I want to use an aftermarket shunt, but which one do I need to buy?

Thanks!

 

[jateureka]

If you are talking about the Turnigy wattmeter then this was answered a few posts back

The original shunt is a 0.001 ohm, 1% tolerance, 3 watt rated surface mount resistor. The meter should work OK with any 0.001 ohm shunt resistor, but may need calibrating after the mod to get the readings spot-on.

I believe the newer models may not have the calibration pots, based on the observations of others, but I'm not sure when this change took place.

If you are talking about the Jaycar wattmeter then that would depend on the current draw for your setup.

 

[MAGICPIE3FOCUSPOWER]

Thank you!

 

[dnmun]

i bot some 4milliohm shunt resistors, surface mount 2512s and can stack 4 of them up and solder the ends together to make 1 milliohm shunt. some of the cheap wattmeters use 3 of the 3 milliohm 2512 shunts to make 1 milliohm.