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Tapping power from a gas engine to light an LED
9

Tapping power from a gas engine to light an LED

Tapping power from a gas engine to light an LED

(OP)
Hi Guys,

I am an Agicultural Engineer (Irrigation & Water Mngt).. and I'll highly appreciate any help/advice you can share on...

I operate on a farm (in the Philippines) several gasoline (anywhere from 6 to 10HP) "pull start" (rather than battery start) engines that drive water pumps. These pumps/engines are operated during the night (it is pitch black!). While the engines/pump are in line of sight, they are located far (100-400 yards) from where we can view them. At present, we do not know wether the engines are ON or OFF unless we inspect them regularly and individually.

Since combustion in the engines is done thru "spark plugs" and a magneto, is it feasible and practical to tap some current from the ignition system to power an LED ?
If so, will it significantly degrade the engine's efficiency?

Thank you,
Paskee
PS. I can get the engines wiring diagram from the manufacturer.

RE: Tapping power from a gas engine to light an LED

2
Find some place to mount a bicycle generator. If there is space under the flywheel to mount a second magneto coil that would be a better place to draw power.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Tapping power from a gas engine to light an LED

A neon bulb can typically be capacitively coupled to the spark plug wire, and made to blink with each spark. But it would be too dim to see from any distance.

What about the oil pressure switch? Most engines of this type would have an oil pressure switch to kill the engine if it runs low on oil. Tap into that signal, determine its characteristics, and take it from there.

RE: Tapping power from a gas engine to light an LED

(OP)
Thanks Waross,

I will try your idea.. in fac .. the engine is coupled to the pump by a pulley/ belt configuration and I can place a smalll bicycle type generator to interface w/ the belt ... my reservation however is that a 2nd magneto is a mechanical solution, another thing that can break ... which we try to avoid as much as possible in the field... good thing is that its not a critical component of the engine/pump function.. I will inform you of the results in a month or so.. Thanks again..Paskee

RE: Tapping power from a gas engine to light an LED

(OP)
Thank you VE1BLL,

I like your suggested solutions.."wire and bulbs":

a.the spark plug tap - the blinking effect is wonderful (easier to see and possibly extends the bulb life).. my thought is however to tap before the spark plug capacitor (on the main magneto) rathar than after (where it could possibly degrade the electrical inout to the spark plug and effect its function)

why NEON ... I did a cursory search, I did not find any advantage over LED?

b. the oil switch ... you are correct, a few of the engines have thie feature ..

I will ask the manufacturer ( Briggs and Stratton ) about both these solutions, snd what maximum power I can draw w/o affecting the engine.

Tahnks again VE1BLL...Paskee

RE: Tapping power from a gas engine to light an LED

LEDs (being semiconductors) are naturally more sensitive to high voltage spikes (but reportedly not as sensitive as one might think). Neon bulbs (e.g. NE-2) would probably be more forgiving in a spark plug driven system.

For low voltage applications, it's gotta be LEDs all the way.

RE: Tapping power from a gas engine to light an LED

I some lawn mowers where there is a battery start, they use a sort of second magneto to charge the battery. I assume the windings may be different to gain a lower voltage. The problem is this fixture is part of the casting of the engine like the magneto (or the bolt holes would be).

The bicycle generator is somewhat inexpencive, which make it a good solution.

Most neon bulbs have a 90V conduction voltage, which is why they work well for high voltage. The current demand is also small, so a resistor is placed in series to drop the voltage. Most LED's have a turn on voltage in the 1 to 2 volt range, which makes them a little more problematic.

RE: Tapping power from a gas engine to light an LED

I like Bill's idea for the bicycle generator.

RE: Tapping power from a gas engine to light an LED

LEDs run on DC, so you'll need a rectifier.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies to make the best use of these Forums?

RE: Tapping power from a gas engine to light an LED

(OP)
HI Guys,

The bicycle dynamo (runs by friction )probably will not work. I just called a mechanic at a bysycle shop..he said the bicycle dynamos were built tor maximum of 200 rpm.. an engine running at 2000-3000 rpm will smoke the dynamo. It means placing a reducing wheel to accomodate the speed.. that is another part/complication.

Also, they are expensive.. $100 for a dynamo(hub based) LED combination ! the engines they are running cost brand new about $300.. it seems a mismatch.

Thanks.. Paskee

PS.. The electrical solution ( I hopw it turnss out to be inexpensive). My thinking was small LED flashlights are so inexpensive ($5).. that I can get away with some wires and an pre-mounted LED light .. we have about 17 engines nad my farmer neighbors can benefit too from a solution.

RE: Tapping power from a gas engine to light an LED

So the purpose of the LED would be so you could look across the field and see if it is running? Does that mean you now have to have someone looking at the lights regularly? Or how often do you inspect to ensure that they are operational?

If I were doing this, my thought would be to have an alarm to alert me when an engine was off, instead of constantly having to go monitor for lights at each one. Maybe even set it up so that you are monitoring what the engine is doing(water pressure/flow I presume?), and that way you can catch issues aside from engine running.

Seems like a simpler solution would be to go on a walk around the field every so often :)

RE: Tapping power from a gas engine to light an LED

How about reflectors and a spot light. Put a reflector on the pulley and hit it with a spot light. If its spinning you'll know it.

RE: Tapping power from a gas engine to light an LED

(OP)
Hi BRADRRS,

If we have 17 engines, and view (via binoculars) that a light that is supposed to be on on say location #6 is OFF..we will know that that engine is not working and then go out and fix it. The farm is about 20 acres. It takes anout 1.25 hrs to walk the periphery during the day, about 2.5 hrs in the night ( there are no roads or walkways.. just small paddy embankments..about 1 ft wide, earthen (snake risk, too!) .. and it is pitch black. It is third world situation, no electricity, etc.) Pressure, water flow is not a big concern.. just if it is running or not.

BTW... you presented a GREAT idea.. why not produce a signal when it is off (not when it is ON).. since the engines are running 95% of the time.. we save money by turning on an LED/or NEon bulbs only 5 %.. then batteries might work!

Thanks you... Paul

RE: Tapping power from a gas engine to light an LED

(OP)
Hi Telecomguy,

Your spotlight / reflector idea ... kinda far (400 yards) and electricity is not available.. I got to power the spotlight w/ batteries

Thanks..Paskee

RE: Tapping power from a gas engine to light an LED

I think bradrs is on to something. Far easier to tell if one light is on than to tell that only 16 out of 17 are on, particularly if there isn't good and consistent angular separation between them from the observation location.

RE: Tapping power from a gas engine to light an LED

You can go four ways. Two of them would be energy harvesting.

1) A generator. It can be any really small dc motor recharging a battery.
2) Thermal harvesting using the rejection heat of the exhaust.
3) Vibrational energy harvesting using the engines vibration.
4) Lastly would be solar. You could use the typical junker solar lights and use a vibration or pressure (water) switch to turn them on and off.

In all cases you'd want a simple blink of a high brightness LED pointed in your direction.

Now if we can just find an applicable product ready made.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Tapping power from a gas engine to light an LED

I'd go with Keith's last option, but add to the possible sensing modalities, exhaust temperature. Therefore, a standard backyard solar light that turns on when the exhaust temp drops below a set value, and the battery can be recharged during the day.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Tapping power from a gas engine to light an LED

(OP)
Hi Itsmoked/IRStuff,

Thank you.. but, I am looking for a $10 solution! .. Paskee

RE: Tapping power from a gas engine to light an LED

If the engines are available with an electric start/battery charging function, then changing the magneto coil to a unit with battery charging capability will give you a usable voltage. One unit may be used to power several nearby pumps if you go with a battery and a lights on for failure solution. A sail switch in the cooling air flow may be cheap to make. Use a piece of plastic sheet glued to the arm of a limit switch.
I hadn't thought about exhaust heat. If you buy some TC extension wire you may construct some thermo-piles that will generate enough power and voltage to light an LED when the exhaust is hot.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Tapping power from a gas engine to light an LED

I would put a piece of 3M reflex tape on a paddle that gets turned away by exhaust gases and turned back in your direction when engine stops. You can scan the field with a bright LED torchligt and binoculars. If you see bright reflexions, you have engines that do not run.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Tapping power from a gas engine to light an LED

One issue with motion activated mechanisms is that you need to make sure that wind cannot cause the same effect.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Tapping power from a gas engine to light an LED

Sure, you need to take wind direction and speed into account.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Tapping power from a gas engine to light an LED

The $10 budget makes 'lit when not running' more difficult.

I'd start with about five turns of #24 solid insulated wire wrapped around the engine's spark plug lead and just soldered to the terminals of an LED. If the LED burns out quickly, insert a resistor.

Mike Halloran
Pembroke Pines, FL, USA

RE: Tapping power from a gas engine to light an LED

Dead end. Too weak current, too short duration. And winding secondary around primary winding doesn't make a transformer.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Tapping power from a gas engine to light an LED

What about a nylon wind sock that gets inflated with the exhaust port of the engine? If it's sticking up in the air and waving about you know the engine is running.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies to make the best use of these Forums?

RE: Tapping power from a gas engine to light an LED

All these engines will have a wire to short out the "points" whether mechanical or an electronic module to stop the engine. A capacitance load of .047 connected to this lead should have no effect on the ignition system. Just add a full wave rectifier and small cap to extend the pulse should produce power for the LED. Add current limiting resistor selected more to extend out the pulse than to actually limit current. My experience with LED has shown that these easily "ghost" with as little as a couple microamps of current. On a really dark night these should be visable if a reflector is included to spread out the light. When this rain stops I will try this on my lawnmower.

RE: Tapping power from a gas engine to light an LED

(OP)
HI Operahouse,

Plese tell me your what happened to the device on your lawnmower.. maybe the solution I am looking for
Thanks
Paskee

RE: Tapping power from a gas engine to light an LED

I tried the experiment on the lawnmower today and the results were good. I used a 3W 120V 6X6 LED assembly
which the normal power board had beenremoved because of damage. That 6X6 array in series normally starts
conducting at about 90 some volts if I remember. My power circuit was a .1uF 400V capacitor from the points
connected to the center of two 1N4005 diodes in series. The minus side of the diode string connected to ground.
The + side of the string connected to another .1uF cap filtering the output and a 300 ohm resistor going to the
+ side of the LED string. Engine was run at a fast idle and I estimate this was maybe 0.1 to 0.25W of power going
to the lamp. Not bright but clearly visable in daylight. I tried another 120V LED lamp directly across the
points but that didn't work at all. This is likely because these lamps normally contain an anti ghosting
resistor that places about a quarter watt resistive load on the lamp. This prevents household wiring capacitance
from causing the lamp to ghost on when not actually powered. It is likely a commercial 120V lamp would work
if this ghosting resistor is removed. Typically the resistor value is between 47,000 and 100,000 ohms. I
measured the AC voltage at the points and it was about 100V making these LED lamps a good match. Is the
normal line voltage there 220V?. My LED was white. If a 36 LED string could be found that might be more
efficient.

RE: Tapping power from a gas engine to light an LED

Last sentence should read ...red 36 LED string.

RE: Tapping power from a gas engine to light an LED

(OP)
Thanks Opera House,

1. The normal line voltage in the Phils is 220Volts... but there is no elctric service in the farm ... we have a small generator.. but thta's it.

2. I am gald your lawnmower worked ! And if you can see the LEd during the day.. it surely will work during the pitch black of the night ! Hooray!

3. Where did you connect the LED wire? ( you mentioned points?)
Paskee

RE: Tapping power from a gas engine to light an LED

I was wondering about the voltage to see if locally supplied LED lamps would work like those with an E27 base. Some China made lamps are easy to snap apart plastic cases. With these you could open them up and remove the anti ghosting resistor and then you would be all set to just connect them to the points. Do you buy on ebay? Just need some comonality where we can view the same item. As this is a RE project, it might be of interest to others and we could work together on it on fieldlines.com

RE: Tapping power from a gas engine to light an LED

(OP)
Hi OperaHouse,

1. I am US base, living in California.. so I can buy the components here.
2. Yes, I can buy at ebay, Amazon, or wherever in the het.
3. Sorry, but I still do not what connection to the points is/are..please elaborate.
4. What also is an RE project... "real experience" ?

thanks a lot..
Paskee

RE: Tapping power from a gas engine to light an LED

(OP)
Hi OperaHouse,
I went to www. fieldlines... your description was of the schematics was good... the pictures were truncated (incomplete).. can you please send the pictures directly to me...appreciate it greatly... thanks paskee

RE: Tapping power from a gas engine to light an LED

The pictures are fine there. Try using a different browser to look at them.

Or right click on them and "save picture to" a file on your desktop and look at them without a browser.

You're not allowed to put your email address in these forums so I don't see how opera is going to "email you".

Keith Cress
kcress - http://www.flaminsystems.com

RE: Tapping power from a gas engine to light an LED

(OP)
Hi Keith,

Got the pix/circuit... thanks ... I will try it as soon as I get an engine

PAskee

RE: Tapping power from a gas engine to light an LED

The bulb that seems to be the one I used is lights of america 2101LEDG10 - 41K MR16.
I haven't been able to find other suitable lamps with a single LED die. I did purchase
from China a lamp identical to this ebay #170942327062. The case did snap apart.

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