Honda/Huasheng/Titan,Lighting & Electrical System.

[fetor56]

Devoted specifically to the Honda GXH50 engine but i see ablolutely no reason why it won't work on the others;any suitable others.
Use the black kill switch wire as an electrical power source as it powers 12Volt LED's.I don't know the exact voltage or current yet cos i've just noticed this.I HAD to start the engine first & then switch on the light which suggests low useable current.
The engine can also be killed with the same black kill wire but i'm not overly keen on that,& i'm NOT aware of any OTHER wire that can be used to kill the engine.............kill suggestions anyone?
The pic doesn't do justice to the LED's brightness because of the flash of the camera.

 

[Irish John]

Can someone shine a light on this?

Electrics are not my best subject so you are saying to take one wire off the black and connect to the 12v LED and another wire off the light's terminal and connect it to earth. Is there a 12v halogen car light that could be used? This renders the kill switch defunct I take it but does taking current off the motor affect it's ability to function normally I wonder?
This might be a great breakthrough Fetor.

 

[fetor56]

Electrics are not my best subject so you are saying to take one wire off the black and connect to the 12v LED and another wire off the light's terminal and connect it to earth. Is there a 12v halogen car light that could be used? This renders the kill switch defunct I take it but does taking current off the motor affect it's ability to function normally I wonder?
This might be a great breakthrough Fetor.

That's exactly what i'm saying....u CAN also run a LED tail-light continuously(even at start-up)
With headlights i think u would need to start the engine then turn the lights on.
I havn't noticed any ill-effects with using the black kill switch wire as a power source,BUT it's still early days..........start small.

 

[skyl4rk]

You should still be able to use the kill switch, it would just bypass the light and ground out the power.

A current regulator would be a good idea.

http://www.instructables.com/id/Super-simple-high-power-LED-driver/

The output is likely pulse dc. A largish capacitor in line would help smooth the voltage peaks.

What does the voltmeter say?

 

[HoughMade]

I am watching this thread with much interest. I want to add a headlight, turn signals and a tail/brake light.

If this works, I would like to mount a smallish SLA battery and use the black wire to charge the battery and run the lights off of the battery. If there was a discharge condition with everything on, that's OK because if I started with a fully charged battery, I imagine the charge would allow the battery to run everything for a long, long time.

 

[HoughMade]

So just thinking out loud. If the Honda is putting out pulses of DC (if its AC, of course I would add a rectifier and elminate the other diode), why couldn't I run that into an inductor (made my own once to filter alternator whine from my car stereo) to smooth it out, through a voltage regulator to keep it from going much above 14 volts, through a diode to keep 1 way flow, and into a 12 volt lead acid battery. The inductor probably would be necessary, but what could it hurt?

So far we don't know how much power can be pulled from the kill switch wire, but even a few hundred milliamps would stretch the usable time on the battery, wouldn't it?

I'm no electrical genius, so feel free to correct and criticize me.

 

[skyl4rk]

Here are some of the measurements that I would do to design a system:

1. Measure Voltage while motor is running at idle. I do not believe that the Voltage will be AC, it will likely be pulse DC. Your meter will translate pulse DC to an average voltage.

2. Put a diode inline and measure voltage behind the diode. It will likely be about 1.5V less than the previously measured Voltage. This is the voltage available for charging. You should measure at idle and at higher rpm, for example cruising speed rpm.

3. Put a potentiometer in the circuit and turn it until the motor stops running (idle speed). Take the pot out of the circuit and measure the resistance. Voltage at idle divided by Resistance in ohms where the motor dies equals the maximum amount of amps you can draw before killing the motor at idle.

With that information and an idea of what loads you want to power, one could start to design a system.

You have the right idea about how it would be done. I don't think you will need a rectifier. An inductor would smooth out the pulse DC, as would a capacitor. What to do with voltage regulation depends on how much voltage you have to deal with, and how many amps you can draw before killing the motor.

You may be able to use a simple zener diode voltage regulation system, or you may want a solid state voltage regulator. If the voltage is right, you may not even need any regulation.

 

[HoughMade]

Great info. Thanks!

 

[skyl4rk]

I have a Dax Titan kit on its way, so I may be able to take some measurements soon.

 

[duivendyk]

I doubt that it is a pulsed dc signal more likely ac pulses,no inductive device is capable of such a feat without either a rectifier or a commutator, as in dc generators.Be this as it may ,LED's can run on an ac voltage provided the reverse voltage is not excessive.If you put two back to back you are on safer round since the forward voltage on one limits the reverse voltage on the other one, but each will generate light only half the time.I think that taking some measurements would be useful in designing a safe system.Sticking a diode with a voltmeter behind it gives you only limited info,you will get a series of voltage pulses which the meter will average in some fashion,it tells you nothing about the peak value which is also important to know.Assuming that you were reading a positive dc output in the first test,then as a second measurement stick a electrolytic cap (say 22 micro farad or more with a 25V rating,the value is not critical) to ground, that is the lead from the diode with the band next to it should be connected to the + side of the cap and the other side of the cap to ground. Then read the voltage again.It's probably quite a bit higher.Repeat the whole procedure including the first measurement but reverse polarities of diode& cap.You should now read voltages of the opposite polarity.It would be helpful to do it at normal running rpm and also at idle.Lastly with the engine turned off measure the resistance to ground of the black wire. This is also important to know.Be advised that LED's do NOT behave as normal linear resistors,more like crummy diodes.The current goes up exponentially and only the source resistance will limit the current and keep them from getting fried,you seem to have lucked out.If the drain on the ignition system is too high the engine would quit, which is just as well
It would also be useful to know at what load the ignition malfunctions, but that would take a number of resistors to try, or better a variable resistor.BTW there is absolutely no harm in using the kill switch in the normal fashion.I hope you have a multimeter.One thing I forgot to mention, put a large resistor 100k or so across the cap to discharge it between measurements or else short it out before you start a measurement,the only drain on it is the Voltmeter,some of the digital ones have an 10 Megohm or higher input resistance which could conceivably result in false readings