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Fuel gauge


edwardc
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I think the best solution to this problem is a capacitive device which is basically two electrodes in the petrol and the further up the electrodes, the greater the capacitance. It's then fairly trivial to come up with the electronics to give you a read out. One of the biggest reasons that this is suitable is it lends itself to the peculiar shaped tanks that many of us have to contend with.

At a much simpler level (scuse pun) is a simple float switch that brings on a warning light when the fuel drops beyond a certain level. If you go for this option, make sure you chose a switch that is suitable for immersion in petrol.

I also saw somewhere today a direct reading (I think mechanical) gauge for paramotors, which came in about £150 which I think is absurdly expensive.

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Some great ideas. I love the Micro fuel gauge Mike.

We need to put our ideas together and find a cheap way of doing this. I can put a float switch in that will tell me when I am at a specific point in the fuel cycle very cheaply (as per Phil) but we need to monitor all the time. The option is to put 3 or 4 in connected to seperate LEDs or optic switches but that is also expensive.

I can get a row of LEDs from Maplins to use but the variable tank sender units are too expensive.

The electrode idea sounds good if we can get more info (Ben).

This is the best think tank for Paramotoring so lets have any more ideas and I am sure we will sort it.

Cheers

Eddie

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I looked at Jim Weirs site just now, that 'PCB' looks a right mess!

This kit is for 'fluid' so will need to take into account the properties of petrol. I like the LED arrangement; http://www.electronic-circuits-diagrams ... ckt6.shtml

Some more info here, schematics etc...; http://www.rcgroups.com/forums/showthread.php?t=914185

Can we not have this sensor at whatever litre we decide is 'turn around now', then simply run it to a small 'hobbie' box mounted on the chassis with an LED and 9v battery inside? Or, another two or three if you want 'full' tank, 'half' and 'low'... http://docs-europe.electrocomponents.co ... 40c2e2.pdf a single sensor is only £13...

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I looked at Jim Weirs site just now, that 'PCB' looks a right mess!

This kit is for 'fluid' so will need to take into account the properties of petrol. I like the LED arrangement; http://www.electronic-circuits-diagrams ... ckt6.shtml

Some more info here, schematics etc...; http://www.rcgroups.com/forums/showthread.php?t=914185

All you'd have to do to have LED's with Jim's circuit would be to run an A to D converter to drive them.

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Ben

Mentioned the multiple sensor idea before but at £13 a time without the LEDs we are getting near the price of the micro fuel gauge already made up!

Eddie

Oh ok, well I worked it out a bit cheaper...

Miniature case: £1.59

Green LED (8mm): 39p

Orange LED (8mm): 39p

Red flashing LED (8mm): £1.09

3 Level Sensors: £40.98

Sundries (washers etc): £3.00

TOTAL: £47.44

Plus, assuming it works, it can be bought it kit form and made yourself...or pay a bit extra for the PMC, prebuilt version. You also have the choice of going for a simpler version with only the one sensor and flashing red LED for when you are low...

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A flashing light when you're low is not really good enough is it.....? when you're planning your flight, you need to take into consideration where you're going, the distance, airspeed, wind direction, anticipated groundspeed, etc.... will give you a rough idea on how much fuel you're going to use- providing you know your burn rate. Add around say a litre for reserve and you can get it spot on normally.

When i'm flying every so often i think about fuel level- but before i glance at my tank, i make an estimation of what i expect to see there- for example if i've taken off with 5 litres, and been flying for 40 mins then, i expect to see 2 litres in the tank.... I also know that i've got another 40 mins left for the mission, and 20 minutes reserve should it be necessary... This is a much better way of monitoring the fuel level.... instead of waiting for a LED to start flashing.... I certainly wouldn't waste money on this, unless it gave me a calibrated indication of what was actually in the tank, so that i could monitor burn rates.....

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You're right Gordon, I guess we should always know how much fuel is in the can. But, like on a car, it would be nice to have a little reminder maybe? For the times you're having such a good flight, times literally flying...and before you know it, the motor is coughing and spluttering...

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Im sure this guy is on the forum

He mentions a fuel low level light in this video and how he did it.

http://uk.youtube.com/watch?v=AjNNmhfQL ... annel_page

Just had a look and he uses the same switch as I have gone for, but may be cheaper as from a different manufacturer. He only has the one sensor so the two LEDs are overkill really.

EdwardC: http://uk.rs-online.com/web/search/sear ... breadCrumb

There are two manufacturers, Gem and Honeywell...

The deisgn id so very simple, nothing to go wrong really.

Ben

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You're right Gordon, I guess we should always know how much fuel is in the can. But, like on a car, it would be nice to have a little reminder maybe? For the times you're having such a good flight, times literally flying...and before you know it, the motor is coughing and spluttering...

Ben i don't accept this arguement- during a flight there are so many factors that you must continually consider and constantly evaluate- anyone who could inadvertently run out of fuel is not truely 'piloting' the machine.... If you're having a 'such good' time not to notice the gust front approaching, or cumulus stacks forming, then you are going to have more serious issues.

Calibrating a tank to activate a 'low' fuel light is a waste of time- might as well just wait for the ceasation of vibration/noise.... the best indication of all that you're out of fuel.

I consign electronic fuel level guages for paramotors to the same category as chocolate fireguards, glass hammers, rubber nails, motorcycle ashtrays,

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I consign electronic fuel level guages for paramotors to the same category as chocolate fireguards, glass hammers, rubber nails, motorcycle ashtrays,

Presumably you also dispense with the little mirror then Gordon, as it is just telling you what you already know? If you still use the mirror, then what is wrong with using a workable alternative, electronic or otherwise?

Personally, I know that the mirror system is fallible, as I was convinced that I had plenty of fuel the other day, because I was using the mirror. As it happens (and don't ask me how) what I saw in the mirror was not reflected (sorry) in reality. Maybe a trick of the light, maybe abject stupidity (which I suppose you can't really make contingency for), but I ran out about 4 miles from goal and about 20 minutes earlier than expected.

I like doing a fuel plan, but higher than expected winds aloft, resulting in you using the speed bar loads can make a huge difference and throw out planning to a massive extent. As I've only just started using mine, and I was only using it intermittently, I had no real idea how it would affect my fuel burn.

Lets face it, the reason that fuel planning is drummed into PPL pilots, is mainly because the fuel gauges are so abysmally inaccurate in most light aircraft.

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