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Electronic fuel gauge damper

salty_monk

Forum Guru
Past Site Supporter
TGSR Superstar
I have Koso XRSR gauges on the 750 and the fuel gauge is very accurate but it changes with angle of the bike etc even worse than a stocker On my 78 1000.
( where I assume just the slow speed of the needle acts as a bit of a damper).

The stock 750 moved a lot less so I guess Suzuki did something to the gauge to damp the movement. That one stayed at level with power off 78 does not.

So is there anything I can add to the power line to damp response without changing it's resistance? I don't want to change the way it reads just slow it down a bit.

The resistance is approx 0-120 ohms
 
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fill the gas tank with oil :-\\\; that should dampen it.













sorry; unless filtering power to the Koso the only other thing would be to build a smart gas tank gauge which monitors fuel consumption and severely averages the data. It would regenerate a voltage to make the Koso indicate a smooth tank level. I'll look at a few things today.
 
I figured... it's almost like you need a "slow read" so that the gauge only reads when the level has remained constant for a second or two otherwise it stays at previous reading.

It's not a big deal, what makes it more noticeable is that the Koso flashes when the gauge hits reserve (3 bars out of ten). On a half full tank you can easy get it into that zone on a corner.

The Koso accuracy of speed is the best I've seen from any of these electronic type speedo's. It can sense from up to 6 magnets (I use 5 as it's a 5 bolt rotor) so it doesn't have the typical delay that this type of sensor shows as it's reading 5 times a revolution (1852mm so about one read per foot travelled).

Dan :)
 
I figured... it's almost like you need a "slow read" so that the gauge only reads when the level has remained constant for a second or two otherwise it stays at previous reading.

It's not a big deal, what makes it more noticeable is that the Koso flashes when the gauge hits reserve (3 bars out of ten). On a half full tank you can easy get it into that zone on a corner.

The Koso accuracy of speed is the best I've seen from any of these electronic type speedo's. It can sense from up to 6 magnets (I use 5 as it's a 5 bolt rotor) so it doesn't have the typical delay that this type of sensor shows as it's reading 5 times a revolution (1852mm so about one read per foot travelled).

Dan :)

Do you know where I can pickup a cheap magnetic pickup for am Innovate LM-2 data recorder? It can be general purpose.

So is the front rotor the most convenient place to pickup the bolts going round?

Looks like the only thing I can really use is the rear sprocket carrier bolts. I can made a pretty stout mount off the lower shock bolt (no more than 2"-3" long.
 
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The Koso & the Acewell pickups are magnetically switched. In the case of both you just put a magnet in range & away you go.

A Sigma bicycle pickup might be your cheapest route but Koso & Acewell sell them as accessories.

The Koso set comes with 6 very strong tiny magnets that you put in the allen head of the rotor bolts. You can also purchase bolts from them with a magnetic head too....

You can pick up any source that turns round once a wheel revolution I guess....

There are some "proximity" sensors on some of the digital car speedo's I've seen. These just need to be placed a couple mm from a bolt head/end & they trigger without any magnets. Not sure where you'd get one of those...
 
The Koso & the Acewell pickups are magnetically switched. In the case of both you just put a magnet in range & away you go.

A Sigma bicycle pickup might be your cheapest route but Koso & Acewell sell them as accessories.

The Koso set comes with 6 very strong tiny magnets that you put in the allen head of the rotor bolts. You can also purchase bolts from them with a magnetic head too....

You can pick up any source that turns round once a wheel revolution I guess....

There are some "proximity" sensors on some of the digital car speedo's I've seen. These just need to be placed a couple mm from a bolt head/end & they trigger without any magnets. Not sure where you'd get one of those...

I won a pair of these. They are magnetic sensors that generate a change in output based on coming close to a peice of metal. They are also active in that they have preamplifiers that square up the signal inside so that the there is more noise immunity and the device will work up to 6mm away from the metal it is detecting. So I should be able to detect each of 5 bolt on my sprocket carrier by mounting off my rear shock mount.

If this is non threaded, then you make a clamp queezes down like a triple tube clamp.

Rockwell Long Range Inductive Proximity Sensor NEW 2CT!

Manufacturer: Rockwell Aut.
Model: 872C-M6NP12-D4
Description: Rockwell Long Range Inductive Proximity Sensor NEW 2CT
Condition: New
Packaging Condition Details: Good Condition

New
Quantity: 2CT
Item: Long Range Inductive Proximity Sensors
Bulletin: 872C
Input: 10-30VDC
Load-200mA Max
Output: NO
PNP Quasi
Sens. Dist-6mm
Items are new in original manufacturer sealed packages. Packages are in good condition.
 
A Sigma bicycle pickup might be your cheapest route but Koso & Acewell sell them as accessories.

I fitted a Sigma to a BMW R100 a while ago and used a rare earth magnet from an old PC harddrive to trigger it. Just a dab of epoxy under it, but it was difficult to get it off without the epoxy anyway.
 
Dan,
After getting my voltage regulatro to work I did notice there was still alot of fuel gauge movement. I did a little work on a damping unit based on the GS 82/83 1100 magnetic fuel gauges. Finally after looking around there is apparently an anti-slosh module in some FORD's. No sure what tehy use, but the circuit I came up with is similar in principle to this one.
The circuit operates on the basis that the gauge deflects on the basis of a voltage into sensor output. Normally with just a passive resistor the gauge deflects based on the current flow allowed through the external sensor.
Anyway, by monitoring the sensor through some type of voltage divider, a Low Pass Filter (time constant in the seconds) voltage follower can be used to drive the gauge. The voltage follower has a FET at it's output to have the drive capability for the relatively low reistances in the gauge.
I was testing the principle last nite with a fuel gauge but could not beleive how slow it was. Apparently the oil had not run out of it. It takes 15-20 seconds for it to swing full scale.
Anyway this is the most practical thing to do for an anti-slosh circuit. You can probaly fit it all on a 1"x2" circuit card . I have thought of a combo module to dampen both fuel; and temp but you and I must be the only ones with such problems. :o

Jim

http://www.discovercircuits.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=6590&page=2
 
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Interesting stuff... I'd have to get some breadboard then :D

Shame there is no off shelf module.
 
Interesting stuff... I'd have to get some breadboard then :D

Shame there is no off shelf module.

So how is the gauge setup now

0 to 5V using a 120 ohms voltage divider pot as input to the Koso?

That would be pretty easy.

edit: I just read the Koso unit directions and I can't figure out why they would need to set the unit for ohms. It also says to not leave the stock guage connected. Both of these seem contrary to how a typical analog input would be implemented. Simple A/D converter for a 0-12V input and you don't care what the resistance is. You would need to see if Koso will give you some idea of what the input is as it is not obvious?
 
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Dan,
I drew a circuit of what the Koso is doing. If you could
l check something that would confirm my suspicions.

If you fill your tank and read the gauge it should be at F. Also see if you can measure the voltage going into the Koso.

Then change the resistor setting in the setup. Change the resistor value to twice what you measure full. So if you are normally at 120 ohms F then move to 240 ohms and the display should drop to 1/2 F with no change in the voltage. I'm figuring that your voltage with the 120 ohm resistor is less than a volt. If you had a 240 ohm resistor the voltage would go up to 2V and you would have to adjust the internal resistance setup which tells the device that 2 V is no full instead of 1 volt. That means that you could put a 1.2V batttery at the as an input and get it to read a little over 1/2 when the gauge is programmed for 240.


Basically what is going on is they wanted the gauge to source the current for the gauge voltage divider. Since all gauges are different with different ohms that means the voltage range will change as you connect different sensor to the device. The setup is to recalibrate that.


All the above being true, it should be easy to build a anti-slosh circuit.
See attached for illustarion of what I suspect KOSO are doing. Your measurements would confirm that.
 
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There are only 2 input selections on the Koso either 100ohms or 500 ohms.

Does that mean I need to test in a different way?

We could always steal Bruce's meter in Reno & take a look I guess..!
 
There are only 2 input selections on the Koso either 100ohms or 500 ohms.

Does that mean I need to test in a different way?

We could always steal Bruce's meter in Reno & take a look I guess..!

Well we could, but in the mean time do a quick test.

1.) Fill gas tank
2.) Set Koso to 100 ohms range selection
3.) measure voltage at the input to the Koso_____
4.) Note fuel display reading_______
5.) Set Koso to 500 ohm range selection
6.) Measure the voltage at the input to the Koso_____
7.) Note Fuel display reading_______
 
OK, I will try to do so asap. I'm not 100% I can get to it without removing fairing etc now so might not be as quick a job as it first sounds :)
 
OK, I will try to do so asap. I'm not 100% I can get to it without removing fairing etc now so might not be as quick a job as it first sounds :)

You can measure the voltage at the sensor as well. No need to undo the fairing; it is the same connection.
 
Jim

No need to lift the tank either... I've been messing with bikes to get ready for the weekend and no time for this yet... I'll be bringing a meter with me in any case.

Dan
 
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